Category Archives: Ratings

False Trochanter Mealybug | Pseudococcus dolichomelos

California Pest Rating  for
False Trochanter Mealybug | Pseudococcus dolichomelos Gimpel and Miller
Hemiptera: Pseudococcidae
Pest Rating: A

 


PEST RATING PROFILE

Initiating Event:

Pseudococcus dolichomelos is currently Q-rated.  A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background:  This mealybug is found underground on the roots and crown of its host plants (Gimpel and Miller, 1996).  It presumably feeds on roots.  It has been associated with plants in at least 12 families: Amaryllidaceae, Asteraceae, Euphorbiaceae, Fabaceae, Hypericaceae, Onagraceae, Poaceae, Polygonaceae, Rosaceae, Solanaceae, Urticaceae, and Zingiberaceae (García Morales et al., 2016).  The biology of this recently-described (1996) species is poorly known.

Worldwide Distribution:  Pseudococcus dolichomelos occurs in the eastern United States (Florida, Louisiana, Maryland, Michigan, New York, North Carolina, South Carolina, Texas, Utah, Washington, D.C., and West Virginia) and Hawaii (García Morales et al., 2016; Gimpel and Miller, 1996; von Ellenrieder and Watson, 2016).

Official Control: Pseudococcus dolichomelos does not appear to be under official control anywhere.

California Distribution:  Pseudococcus dolichomelos is not known to occur in California (Symbiota Collections of Arthropods Network).

California Interceptions:  Pseudococcus dolichomelos has been intercepted in California associated with cut flowers of Alpinia purpurata, Oncidium sp., and Zingiber sp. from Hawaii (PDR # 1367825, 1367535, 070P06137999, and 100P06282530), peaches from Utah (PDR # TR0P06024371), and primrose plants from Florida (PDR # 370P06678226).

The risk Pseudococcus dolichomelos would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Pseudococcus dolichomelos occurs over a wide portion of the United States, including areas with temperate (e.g., Michigan) as well as tropical/subtropical (e.g., Hawaii, south Texas) climates. This suggests that this species is capable of becoming established over a wide portion of California. It has been associated with a wide variety of plants in 12 families, so it is not expected to be limited by distribution of potential host plants.  Therefore, Pseudococcus dolichomelos receives a High (3) in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Pseudococcus dolichomelos has been associated with, and presumably feeds on at least 12 families of plants. Therefore, it receives a High (3) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Pseudococcus dolichomelos has been intercepted multiple times on cut flowers and other commodities, so it is evidently capable of being spread artificially on infested plants.  Therefore, it receives a Medium (2) in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Root-feeding mealybugs include species that are pests of food and ornamental plants.  However, dolichomelos is not known to be an economic pest anywhere it is known to occur, even though it occurs over a wide area.  Therefore, it receives a Low (1) in this category.

Economic Impact:

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Root-feeding mealybugs have the potential to impact the health of plants, as demonstrated by the fact that some are economically-significant pests. If Psuedococcus dolichomelos became established in California, it would encounter species of native plants, including many rare ones, that it has not previously been exposed to.  It is possible that it could have an impact of some of these plants.  Therefore, it receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Pseudococcus dolichomelos: Medium (11)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Pseudococcus dolichomelos is not known to occur in California.  It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (11)

Uncertainty:

The most important uncertainty regarding this species is its ability to significantly impact the health of plants; this has not been shown to be the case anywhere it currently occurs.

Conclusion and Rating Justification:

Pseudococcus dolichomelos is a root-feeding mealybug with a broad host range.  It is not known to occur in California, but it is likely capable of becoming established over a large portion of the state.  If this was to occur, it is not likely to become an economic pest, but there is a chance that it could impact the environment.  For these reasons, an “A” rating is justified.


References:

García Morales, M., Denno, B.D., Miller, D.R., Miller, G.L., Ben-Dov, Y., and Hardy, N.B. 2016. ScaleNet: A literature-based model of scale insect biology and systematics.  Accessed November 7, 2017.  http://scalenet.info.

Gimpel, W. F. and Miller, D.R. 1996. Systematic analysis of the mealybugs in the Pseudococcus maritimus complex (Homoptera: Pseudococcidae). In (B.K. Gupta, ed.) Contributions on Entomology, International (pp. 38-42).  Associated Publishers.  Gainesville, Florida.  163 pp.

Symbiota Collections of Arthropods Network.  Accessed March 7, 2018. http://scan1.acis.ufl.edu

von Ellenrieder, N., and Watson, G.  2016.  A new mealybug in the genus Pseudococcus Westwood (Hemiptera: Coccomorpha: Pseudococcidae) from North America, with a key to species of Pseudococcus from the New World.  Zootaxa.  4105: 65-87.


Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov


Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov


Comment Period:* CLOSED

4/10/18 – 5/25/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: A


Posted by ls 

A Burrowing Bug | Rhytidoporus indentatus

California Pest Rating  for
A Burrowing Bug | Rhytidoporus indentatus Uhler
Hemiptera: Cydnidae
Pest Rating: C

 


PEST RATING PROFILE

Initiating Event:

Rhytidoporus indentatus is currently Q-rated.  A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background:  Rhytidoporus indentatus has an appearance typical of members of the family Cydnidae; it is small (3.8-5.8 mm in length), oval-shaped, dark, and shiny (Froeschner, 1954; Froeschner and Maldonado-Capriles, 1992).  Very little information is available on the biology of this species.  It has been found in caves in Cuba and Jamaica, and it was reported to feed on fruit and seeds in bat guano (Barroso and Díaz, 2014; Peck, 1992).  It has also been intercepted on various root commodities, which suggests it may feed on roots as well (see below).  The members of this family are referred to as “burrowing bugs” because most species live underground and feed on roots, but some live above ground and feed on fallen seeds or the exposed parts of plants.  Few species in this family are recognized as economically significant pests.  Among them are some species that damage cassava roots or peanuts (Bellotti et al., 1994; Chapin et al., 2006).  Besides the direct damage to the roots, feeding by these insects can allow infection by pathogens, including fungi.

Worldwide Distribution:  Rhytidoporus indentatus is known from Pacific islands (including Guam), the Greater Antilles (including Cuba), and the United States (southern Florida and Hawaii) (Bishop Museum, 2002; Froeschner, 1976; Lis and Zack, 2010).  It was also apparently collected from Baja California, although additional evidence of this species occurring there was not found (Cervantes Peredo and Ramos Rivera, 2017).  The Greater Antilles distribution is presumed to represent the native range of the species, and the Pacific island, Mexico, and United States records represent introductions (Froeschner, 1954).

Official Control: Rhytidoporus indentatus is not known to be under official control anywhere.

California Distribution:  Rhytidoporus indentatus is not known to be present in California (Symbiota Collections of Arthropods Network).

California Interceptions:  Rhytidoporus indentatus has been intercepted on ginger, sweet potatoes, taro, and turmeric from Hawaii (PDR # 926381, 926378, 1308357, 190P06060306, 190P06620121, and 190P06620007), in the soil of plants from Hawaii (PDR # 1239534), with cut flowers from Hawaii (PDR # 1040836, 1418527, 1418527, and 1396118), with palms from Florida (PDR # 1039799), and in miscellaneous shipments from Hawaii and Florida (PDR # 975978 and 1376006).

The risk Rhytidoporus indentatus would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Except for the record from Baja California, Rhytidoporus indentatus is apparently restricted to areas with a tropical or subtropical climate. The climate of California appears largely unsuitable, but it is possible that this species could become established in a limited portion of the state.  Therefore, Rhytidoporus indentatus receives a Low (1) in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: There is very little information available on the biology of Rhytidoporus indentatus. If it is assumed that the interception records represent feeding on the associated commodities, this species may feed on roots and seeds of a broad range of food plants.  Therefore, it receives a High (3) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Rhytidoporus indentatus presumably flies, as it is sometimes collected at light (Froeschner, 1976).  Therefore, it receives a Medium (2) in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Rhytidoporus indentatus is found in the Caribbean, Florida, and Pacific islands.  Yet, there are no reports of this species being an economic pest, even though it presumable occurs in agricultural situations, based on the fact that it has been intercepted on commodities.  Therefore, it receives a Low (1) in this category.

Economic Impact:

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Rhytidoporus indentatus has been introduced to the United States (Florida and Hawaii) and other localities. Although this species presumably feeds on plants (possibly seeds and roots), there is no evidence that it can cause significant damage to plants.  As explained above, this species is not expected to become an economic pest, so it is unlikely that its establishment in California would trigger treatment programs. Therefore, it receives a Low (1) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact:

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact.

Environmental Impact Score: 1

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Rhytidoporus indentatus: Low (8)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Rhytidoporus indentatus is not known to be present in California.  It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Low (8)

Uncertainty:

There is very little information on the biology of Rhytidoporus indentatus.  The absence of reports of it being a pest anywhere it has so far been introduced to suggests that there is a low pest potential in California as well.  However, it is possible that R. indentatus causes damage to roots underground but the damage is not recognized or not realized to be caused by this species.  There is also uncertainty regarding potential for environmental damage, because this species would have access to native plants in California that it has not previously encountered.  It could, for example, feed on seeds of a rare plant to the extent that populations of such a plant would be threatened.

Conclusion and Rating Justification:

There is no evidence that Rhytidoporus indentatus is a pest or has an environmental impact anywhere it is found.  Although it is not possible to predict with certainty what impact it would have in California, it appears highly unlikely that this species would become a problem in this state if it became established here.  For these reasons, a “C” rating is justified.


References:

Barroso, A.A. and R.B. Díaz.  2014.  Estado de conservaciόn de Jimeneziella decui, una especie cavernícola de Cuba (Opiliones: Laniatores).  Revista Ibérica de Aracnología.  25: 43-57.

Bellotti, A.C., Braun, A.R., Arias, B., Castillo, J.A., and Guerrero, J.M.  1994.  Origin and management of neotropical cassava arthropod pests.  African Crop Science Journal.  2: 407-417.

Bishop Museum.  2002.  Hawaiian All-Species Checklist.  Accessed March 27, 2018. http://hbs.bishopmuseum.org/checklist/query.asp

Chapin, J.W., Sanders, T.H., Dean, L.O., Hendrix, K.W., and J.S. Thomas.  2006.  Effect of feeding by a burrower bug, Pangaeus bilineatus (Say) (Heteroptera: Cydnidae), on peanut flavor and oil quality.  Journal of Entomological Science.  41(1): 33-39.

Froeschner, R.C.  1976.  The burrowing bugs of Hawaii, with description of a new species (Hemiptera: Cydnidae).  Proceedings of the Hawaiian Entomological Society.  22(2): 229-236.

Froeschner, R.C.  1954.  Monograph of the Cydnidae of the Western Hemisphere.  Ph.D. dissertation, Iowa State College.  552 pp.

Froeschner, R.C. and Maldonado-Capriles, J.  1992.  A synopsis of burrowing bugs of Puerto Rico with description of new species Melanaethus wolcotti (Heteroptera: Cydnidae).  Journal of Agriculture of the University of Puerto Rico.  76: 177-185.

Lis, J.A. and R.S. Zack.  2010.  A review of burrower bugs (Hemiptera: Heteroptera: Cydnidae sensu lato) of Guam.  Zootaxa.  2523: 57-64.

Peck, S.B.  1992.  A synopsis of the invertebrate cave fauna of Jamaica.  National Speleological Society Bulletin.  54: 37-60.

Symbiota Collections of Arthropods Network (SCAN).  Accessed March 28, 2017. http://symbiota4.acis.ufl.edu


Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov


Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov


Comment Period:* CLOSED

4/10/18 – 5/25/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: C


Posted by ls 

Pickerelweed | Pontederia cordata L

a Pickerelweed plant
Robert H. Mohlenbrock
USDA, NRCS 1995
Northeast Wetland Flora
@ USDA NRCS PLANTS
California Pest Rating for
Pickerelweed (Pontederia cordata L)
Family: Pontederiaceae
Pest Rating: D | Proposed Seed Rating: None

PEST RATING PROFILE

Initiating Event:

Pontederia cordata currently does not have a rating.  It has recently been recommended by Project Plant Right and by the California Invasive Plant Council as a viable alternative for water hyacinth (Eichhornia crassipes) in water gardens. Reports that P. cordata may be spreading spontaneously in California have prompted this review (Kelch & Murdock, 2012).

History & Status:

Background: Pontederia cordata is a perennial, herbaceous, emergent aquatic plant native to the eastern United States. It has light green stems and leaves, and showy blue-violet flower spikes.  The plant can reach four feet tall with the spike growing to six inches in length.  Pontederia cordata typically grows in shallow water (not more than three feet deep), and inhabits marshes, bogs, and the margins of lakes and streams.

Worldwide DistributionPontederia cordata is native to Canada, Central America, Brazil, the West Indies and Argentina (Horn, 2002). It is naturalized in parts of Australia, Europe, and Africa.  It is considered invasive in Kenya (BioNET-EAFRINET, 2011) and South Africa (Invasive Species South Africa, 2018).  Pontederia cordata is native to the eastern United States. The native distribution of P. cordata is from Nova Scotia to Minnesota, south to Florida and Texas (NRCS, 2002).

Official ControlPontederia cordata is officially a controlled weed in South Africa.

California Distribution: Pontederia cordata is not currently established in California.  There have been occasional finds, but limited in scope. Currently these are interpreted as waifs.

California Interceptions: Pontederia cordata has collected a total of nine specimens in California.  The Consortium of California Herbaria has records in Alameda, San Joaquin, Monterey, and Riverside counties.

The risk P. cordata would pose to California is evaluated below.

Consequences of Introduction

1) Climate / Host Interaction: Pontederia cordata prefers fresh, non-turbid water (Lougheed et al, 2001) which limits the areas of establishment. Risk is Medium (2), as cordata may be able to establish in fresh water areas, an uncommon habitat in much of California.

Evaluate if the pest would have suitable hosts and climate to establish in California.  Score:

Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Host Range: Risk is High (3) as weeds do not require any one host, but grow wherever ecological conditions are favorable.

Evaluate the host range of the pest. Score:

Low (1) has a very limited host range.

Medium (2) has a moderate host range.

High (3) has a wide host range.

3) Pest Dispersal Potential:   Capers et al, 2009 reviewed the functional dispersal traits of aquatic plants and ranked cordata as a “Poorly dispersing species”.  While this plant has the capability of reproducing sexually in its native range, it appears to be limited in other areas, including California, to vegetative reproduction by rhizome.  Therefore, P. cordata receives a Low (1) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Pontederia cordata can form patches which, if such patches developed in canals, could potentially interfere with water flow (Cichra, 2001). Pontederia cordata receives a Low (1) in this category.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact:  G

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: The vegetation and seeds are edible to wildlife (NRCS, 2002) and the plant is a good filtration plant for nitrates (Song et al, 2014).  However, if cordata were to form large patches it could potentially interfere with water flow and trigger treatment programs.  Therefore, P. cordata receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact. Score: 2

Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

High (3) causes two or more of the above to occur.

Consequences of Introduction to California for P. cordata: Medium (9)

Add up the total score and include it here.

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: Pontederia cordata is has only been detected sporadically in California. It receives a Not established (0) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (9)

Uncertainty:

The plant has been a popular aquatic landscaping plant for decades, but has not established itself as a pest.  Uncertainty is Low.

Conclusion and Rating Justification:

Based on the score listed above the pest is low risk for further invasions of California. At this point a D rating is justifed.


References:

 BioNET-EAFRINET.  2011. “Keys and Fact Sheets:  Pontederia cordata (Pickerel Weed).  https://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Pontederia_cordata_(Pickerel_Weed).htm Accessed:  February 28, 2017

CalFlora: http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=9390 Accessed:  February 28, 2017

Capers, R.S., Selsky, R. & Bugbee, G.J.  2009. “The relative importance of local conditions and regional processes in structuring aquatic plant communities”.  Freshwater Biology.  doi:10.1111/j.1365-2427.2009.02328.x

Cichra, C.  2001.  “Physical and vegetative characteristics of floating islands”.  J. Aquat. Plant Manage. 39:107-111.  July 2001.

Consortium of California Herbaria: http://ucjeps.berkeley.edu/   Accessed:  March 1, 2017

Horn, C.N. 2002.  Pontederiaceae. In: Flora of North America Editorial Committee, eds. 1993+.  Flora of North America North of Mexico. 20+ vols. New York and Oxford. Vol. 26, pp. 45-46.

Invasive Species South Africa. 2018.  Plants Search: Pickerel weed (Pontederia cordata). http://www.invasives.org.za/legislation/item/311-pickerel-weed-pontederia-cordata Accessed February 28, 2018

Kelch, D.G., Murdock, A., 2012. Flora of the Carquinez Strait Region, Contra Costa and Solano Counties, California. Madroño 59:47–108.

Long, R.W. & Lakela, O. 1976.  A Flora of Tropical Florida: A Manual of the Seed Plants and Ferns of Southern Peninsular Florida, second edition.  Banyon Books, Miami, Florida.

Lougheed, V.L., Crosbie, B. & Chow-Fraser, P.  2001. “Primary determinants of macrophyte community structure in 62 marshes across the Great Lakes basin: latitude, land use, and water quality effects”. Can. J. Fish. Aquat. Sci. 58:1603-1612.

Natural Resources Conservation Service.  2002. “Plant Fact Sheet:  Pickerelweed (Pontederia cordata L.).  United States Department of Agriculture https://plants.usda.gov/factsheet/pdf/fs_poco14.pdf    Accessed February 28, 2018

Song, B., Mallin, M.A., Long, A., & McIver, M.R.  2014. “Factors controlling microbial Nitrogen removal efficacy in constructed stormwater wetlands”.  Water Resources Research Institute of the University of North Carolina.  WRRI Project No. 11-06-W
June 2014.


Author:

Karen Olmstead, Environmental Scientist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6879; plant.health@cdfa.gov

Responsible Party:

Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6650; plant.health@cdfa.ca.gov


Comment Period:* CLOSED

4/9/18 – 5/24/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

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♦  Comments may not be posted if they:

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Pest Rating: D | Proposed Seed Rating: None


Posted by ls

Dwarf Siberian pine beetle | Dryocoetes pini

California Pest Rating  for
Dwarf Siberian Pine Beetle | Dryocoetes pini
Coleoptera: Curculionidae: Scolytinae
Pest Rating: A

 


PEST RATING PROFILE

Initiating Event:

Dryocoetes pini is currently Q-rated.  A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background: This bark beetle measures approximately 2.5 mm in length.  Adults tunnel through the phloem (inner bark), where eggs are laid.  The larvae feed on the phloem.  This species has been reported to feed on pine (Pinus spp.), larch (Larix spp.), fir (Abies spp.), and spruce (Picea spp.) (European and Mediterranean Plant Protection Organization; Niijima, 1909).  The beetle is apparently not known as a significant pest in its native range (European and Mediterranean Plant Protection Organization).  Dryocoetes species are usually considered “secondary pests” and only attack dead, injured, or otherwise compromised host trees (Vega & Hofstetter, 2014).  At least one species, Dryocoetes confusus Swaine, is a serious pest of fir trees; it is apparently the most destructive member of the genus in North America (CABI,  2017; Hansen, 1996; Vega & Hofstetter, 2014).  The pathogenic fungus Grosmannia dryocoetis is associated with D. confuses (Vega & Hofstetter, 2014).  Similar fungi may also be associated with other Dryocoetes species, including D. pini.

Worldwide Distribution: Dryocoetes pini occurs in the Russian Far East, China, South Korea, and Japan (European and Mediterranean Plant Protection Organization; Park, 2016; Shiraki, 1952).  The species is not known to be present in North America.

Official Control: This species is not known to be under official control anywhere.

California Distribution: This species does not appear to be present in California (Symbiota Collections of Arthropods Network).

California Interceptions: This species is not known to have been intercepted in California.

The risk Dryocoetes pini would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: This species appears to occur primarily in areas with a temperate climate. It is possible that it could thrive in a large portion of California if it was introduced.  The tree genera that this species is known to feed upon occur throughout California.  Therefore, Dryocoetes pini receives a High (3) in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: As stated above, Dryocoetes pini has been reported from several coniferous genera. Therefore, pini receives a Medium (2) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Dryocoetes pini is presumably capable of flight. Movement of wood (especially firewood) is a likely pathway for the human-aided dispersal of this species if it was to be introduced.  Reproductive potential is unknown for this species.  Therefore, pini receives a Medium (2) in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Dryocoetes pini has been reported to be associated with several genera of conifers, including Pinus.  There is a possibility that, if this species was to be introduced to California, it could have a different impact than what is observed in its native range, including killing trees, which could reduce yield of timber.  Significant infestations also have the potential to impact the recreational value of forests.  Therefore, it receives a Low (1) in this category.

Economic Impact:  A

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Major outbreaks of bark beetles have the potential to kill large numbers of trees, which can have long-lasting impacts. Such impacts could include changes in forest composition, destabilization of soil, and even fire dynamics (Jenkins et al., 2008).  There are rare or threatened conifers in California that could be impacted by the introduction of pini.  Therefore, it receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A, B

 A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

 B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Dryocoetes pini: Medium (11)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Dryocoetes pini is not known to occur in California.  It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (11)

Uncertainty:

There is little information available on this species, so it was necessary to draw upon information regarding other species in the genus as well as other bark beetle genera.  There are also no examples of introductions involving this species, so assessment of the impacts of this species requires speculation.

Conclusion and Rating Justification:

Bark beetles can have significant impacts on forests.  One native species in the genus Dryocoetes, D. confusus, is an important pest in western forests.  Even though there is little information on the biology of D. pini, it seems justifiable to use caution and assign it an “A” rating.


References:

CABI.  2017.  Invasive Species Compendium. Wallingford, UK: CAB International. www.cabi.org/isc

European and Mediterranean Plant Protection Organization.  Forest pests on the territories of the former USSR.

https://www.eppo.int/QUARANTINE/special_topics/forestry_project/EPPOforestry_project.pdf

Hansen, E.M.  1996.  Western balsam bark beetle, Dryocoetes confusus Swaine, flight periodicity in northern Utah.  Great Basin Naturalist.  56(4): 348-359.

Jenkins, M.J., Hebertson, E., Page, W., & Jorgensen, C.A.  2008.  Bark beetles, fuels, fires and implications for forest management in the Intermountain West.  Forest Ecology and Management.  254: 16-34.

Niijima, Y.  1909.  Die Scolytiden Hokkaidos unter Berücksichtigung ihrer Bedeutung für Forstschäden.  The Journal of the College of Agriculture, Tohoku Imperial University.  3: 109-179.

Park, S.  2016.  Taxonomic review of Scolytinae and Platypodinae (Coleoptera: Curculionidae) in Korea.  Ph.D. thesis.  Seoul National University.

Shiraki, T.  1952.  Catalogue of injurious insects in Japan.  Preliminary Study Number 71.  General Headquarters, Supreme Commander for the Allied Forces, Economic and Scientific Section, Natural Resources Division.  133 pp.

Symbiota Collections of Arthropods Network.  Accessed March 2, 2018. http://scan1.acis.ufl.edu

Vega, F.E. & Hofstetter, R.W.  2014.  Bark beetles: Biology and ecology of native and invasive species.  Academic Press.  640 pp.


Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov


Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov


Comment Period:* CLOSED

4/9/18 – 5/24/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: A

 


Posted by ls 

Pseudocercospora theae

California Pest Rating for
Pseudocercospora theae (Cavara) Deighton 1987
Pest Rating: C

 


PEST RATING PROFILE

Initiating Event: 

On March 6, 2018, the USDA APHIS PPQ requested State Regulatory Officials to review PPQ’s consideration of deregulation of the pathogen, Pseudocercospora theae at US ports of entry.  A ‘Deregulation evaluation of established pests’ report prepared by PERAL was provided for this review.  Therefore, the risk of infestation of P. theae in California is evaluated and a permanent rating is herein proposed.

History & Status:

Background:  Pseudocercospora theae is a fungal plant pathogen in the Mycosphaerellaceae family, that causes leaf spotting known as, bird’s eye spot disease of tea (Camellia spp.). The pathogen has previously been known by its synonyms, Septoria theae and Cecoseptoria theae (Braun et al., 2012; Farr & Rossman, 2018). Holliday (1980) reported that the fungus causes a “very minor” leaf-spotting disease in tea plants.

Pseudocercospora theae has not been reported in California. In the USA, the pathogen has been reported in Florida since about 1955 and disease caused by P. theae has not been reported after 1998.  It is likely that the pathogen is present at non-detectable levels and kept under control by standard disease management practices in nurseries (PPQ, 2018).

Disease cycle: While information on the specific biology of Pseudocercospora theae is limited, it is likely that its disease cycle is like that of other members of the genus.  Generally, Pseudocercospora-infected plants produce conidiophores (specialized hypha) that arise from the plant surface in clusters through stomata and form conidia (asexual spores) successively.  Conidia are easily detached and blown by wind often over long distances.  On landing on surfaces of a plant host, conidia require water or heavy dew to germinate and penetrate the host.  Substomatal stroma (compact mycelial structure) may form from which conidiophores develop.  Development of the pathogen is favored by high temperatures and the disease is most destructive during summer months and warmer climates.  High relative humidity is necessary for conidial germination and plant infection.  The pathogen can overwinter in or on seed and as mycelium (stromata) in old infected leaves (Agrios, 2005).    

Dispersal and spread: Specific information for Pseudocercospora is lacking, however, its mode of dispersal is likely to be like other species of the genus and include air-currents, rain splash/drops, infected plants and propagative material (PPQ, 2018).

Hosts: Camelia sp., C. japonica (Japanese camellia), C. sasanqua (sasanqua camellia), C. sinensis (tea tree; synonyms: Thea assamica, T. sinensis) (Farr & Rossman, 2018).  Although some species of Pseudocercospora are capable of infecting different hosts within a single family (Crous, et al., 2013), there is no evidence that this is true for P. theae (PPQ, 2018).

Symptoms:  Infected host plants exhibit circular leaf spots no greater than 2-3 mm diam., on both sides of a leaf.  The spots are at first purple red, with an indefinite yellow green border and turn white with a narrow purple red ring (Holliday, 1980) with a narrow, raised rim, followed by a dark marginal line or halo (Braun et al., 2012).

Damage Potential: Specific losses due to Pseudocercospora theae have not been reported.  Ornamental plantings of Camellia species may be affected in limited regions of California with sufficient moisture for pathogen infection and development. The climatic suitability of the pathogen encompasses Hardiness Zones 10-13 (PPQ, 2018; Margery et al., 2008).  Nursery production of Camellia species under controlled and conducive conditions for pathogen development would also be of concern in California.  However, P. theae outbreaks in Florida nurseries were successfully controlled by use of proper sanitation practices and fungicide applications (PPQ, 2018), therefore, it is likely that the same will be true for California.  If left uncontrolled, leaf spotting may lead to disease outbreaks under favorable conditions, wherein photosynthetic areas can be reduced, and in severe infections, leaf wilt and drop may be expected.

Worldwide Distribution: Asia: Nepal, Indonesia, India, China, Taiwan, Pakistan, Sri Lanka, Vietnam; Africa: Ethiopia, Malawi, Mauritius, Tanzania, Uganda; Europe: Georgia, Italy, Netherlands Antilles; North America: Florida; South America: Argentina, Brazil, Peru (Braun et al., 2012; EPPO, 2018; Farr & Rossman, 2018).

Official Control: Presently, Pseudocercospora theae is on the ‘Harmful Organism’ list for Colombia (USDA PCIT, 2018).

California Distribution: Pseudocercospora theae has not been reported from California.  The pathogen is not known to be established in California.

California Interceptions:  None reported.

The risk Pseudocercospora theae would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Limited parts of California with adequate moisture, as in coastal regions of the State where Camellia species are grown, are likely to favor establishment of Pseudocercospora theae.

Evaluate if the pest would have suitable hosts and climate to establish in California.

Score: 2

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: The host range is limited to Camellia [Camelia , C. japonica (Japanese camellia), C. sasanqua (sasanqua camellia), C. sinensis (tea tree)]

Evaluate the host range of the pest. Score:

Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Reproduction is high and dispersal conidia is through windborne conidia, and rain splash or raindrops. The pathogen is also spread through infected plant propagative material.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Specific losses due to Pseudocercospora theae have not been reported. Ornamental plantings of Camellia species may be affected in limited regions of California with sufficient moisture for pathogen infection and development. Nursery production of Camellia species under controlled and conducive conditions for pathogen development would also be of concern in California.  However, theae outbreaks in Florida nurseries were successfully controlled by use of proper sanitation practices and fungicide applications (PPQ, 2018), therefore, it is likely that the same will be true for California.  Uncontrolled infected plants may lose value, however, with control measures adopted, the impact is expected to be low.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: B

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Home garden plantings of Camellia species may be impacted if the pathogen was to establish under favorable environmental conditions and in the absence of adequate disease control.

Evaluate the environmental impact of the pest on California using the criteria below.

Environment Impact:

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact. Score:

– Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Pseudocercospora theae: 9

Add up the total score and include it here. (Score)

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

Total points obtained on evaluation of consequences of introduction to California = 9

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Evaluation is ‘Not established’ in California.

Score: (0)

Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 9

Uncertainty:

There is very limited information available on the biology of Pseudocercospora theae.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Pseudocercospora theae is C.


References:

Agrios, G. N.  2005.  Plant Pathology (Fifth Edition).  Elsevier Academic Press, USA.  922 p.

Braun, U., M. Rybak, R. Rybak, and M. G. Cabrera.  2012.  Foliar diseases on tea and mate in Argentina caused by Pseudocercospora species.  Plant Pathology & Quarantine 2 (2): 103-110.  Doi 10.5943/ppq/2/2/2

Crous, P. W., U. Braun, G. C. Hunter, M. J. Wingfield, G. J. M. Verkley, H. -D. Shin, C. Nakashima and J. Z. Groenewald.  2013.  Phylogenetic lineage in Pseudocercospora.  Studies in Mycology 75: 37-114. Published online: 22 May 2012; doi:10.3114/sim0005. Hard copy: June 2013. www.studiesinmycology.org

EPPO.   2018.   Pseudocercospora theae (CERSTH).  PQR database.  Paris, France: European and Mediterranean Plant Protection Organization.  https://gd.eppo.int/

Farr, D.F., & A. Y. Rossman.  2016.  Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA.  Retrieved August 1, 2016, from http://nt.ars-grin.gov/fungaldatabases/

Holliday, P.  1980.  Fungus diseases of tropical crops.  Cambridge University Press, New York. 607 pp.

PPQ. 2018.  DEEP report for Pseudocercospora theae (Cavara) Deighton (Mycosphaerellaceae: Capnodiales) – Bird’s eye spot. United States Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine (PPQ), Raleigh, NC. 4 pp.

USDA PCIT.  2017.  USDA Phytosanitary Certificate Issuance & Tracking System. Retrieved March 21, 2018. 6:36:50 pm CDT.  https://pcit.aphis.usda.gov/PExD/faces/ReportHarmOrgs.jsp.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

4/6/18 – 5/21/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: C

 


Posted by ls 

Colletotrichum henanense

California Pest Rating for
Colletotrichum henanense F. Liu & L. Cai 2015
Pest Rating: B

 


PEST RATING PROFILE

Initiating Event:  

On October 12, 2017, the California Dog Team a shipment of nuts of Castanea sativa (European chestnut) at a parcel distribution facility in Alameda County.  The shipment had originated in Indiana and was destined to a private citizen in Contra Costa County.  A sample of nuts were collected by Alameda County Agricultural officials, and sent to the CDFA Plant Diagnostics Branch for Diagnosis.  Suzanne Latham, CDFA plant pathologist detected the pathogen, Colletotrichum henanense in culture from the nuts. The identity of the associated pathogen was later confirmed by USDA National Identification Services at Beltsville, Maryland, and marked the first domestic detection of C. henanense in the USA.  Consequent to the California detection, all infected plant materials were destroyed. The risk of infestation of C. henanense in California is evaluated and a permanent rating is proposed.

History & Status:

Background:  Colletotrichum henanense is a distinct fungus species belonging to the vastly morphological and physiological variable C. gloeosporioides and is genetically identified from other species of the complex.  The species was originally described in 2015 from tea plants (Camelia sinensis) and Japanese thistle (Cirsium japonicum) in Xinyang, Henan Province, and Beijing, China respectively (Liu et al., 2015).  The pathogen causes anthracnose disease in its host plants.  Camellia species were affected by anthracnose disease in China where the plant species are used as in production of edible oil, processed tea and as ornamentals (Li et al., 2018; Liu et al., 2015).  The pathogen has only been reported from China until its 2017 detection in the California.

Symptoms: Generally, Colletotrichum-infected host plants exhibit symptoms of anthracnose which include dark brown leaf, stem and fruit spots and wilting of leaves which often result in dieback and reduction in plant quality.

HostsCamellia sinensis (tea tree), C. oleifera (tea-oil tree.  Theaceae); Cirsium japonicum (Japanese thistle.  Asteraceae) (De Silva et al., 2017; Li et al., 2018; Liu et al., 2015).  The detection of Colletotrichum henanense in Castanea sativa (European chestnut) is included here (see: Initiating Event).

Symptoms: Colletotrichum henanense causes leaf spot symptoms. Leaf spots or lesions in tea-oil tree are semicircular or half-oval, brown to black with greyish-white centers.  Severely infected leaves wither and drop (Li et al., 2018).

Disease Cycle: It is likely that Colletotrichum henanense has a similar life cycle to that of other Colletotrichum species and survives between crops during winter as mycelium on plant residue in soil, on infected plants, and on seeds.  During active growth, the pathogen produces masses of hyphae (stromata) which bear conidiophores, on the plant surface. Conidia (spores) are produced at the tips of the conidiophores and disseminated by wind, rain, cultivation tools, equipment, and field workers.   Conidia are transmitted to host plants.  Humid, wet, rainy weather is necessary for infection to occur.  These requirements may limit the occurrence of the pathogen in California fields and subsequently, the pathogen may be more of a problem under controlled environments of greenhouses.  Conidia germinate, penetrate host tissue by means of specialized hyphae (appresoria) and invade host tissue.

Transmission: Wind, wind-driven rain, cultivation tools, and human contact.

Damage Potential:  In China, 40% of tea-oil tree yield loss has been suggested (Li et al., 2018).  A 42.5% incidence of anthracnose disease caused by C. henanense was observed in 85 of 200 young tea-oil plants grown in a nursery in Kunming, Yunnan Province, China (Li et al., 2018).  Generally, anthracnose disease can result in reduced plant quality and growth, and marketability.  Nursery productions of Camellia and chestnut are particularly at risk as nursery conditions are often conducive to infection by Colletotrichum species.  In open fields, disease development may be sporadic as it is affected by levels of pathogen inoculum and environmental conditions.

Worldwide Distribution: Asia: China; North America: USA (De Silva et al., 2017; Li et al., 2018; Liu et al., 2015).

Official Control: None reported.

California Distribution Colletotrichum henanense is not established in California (see “Initiating Event”).

California InterceptionsThe risk Colletotrichum henanense would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Like other species of Colletotrichum henanense requires humid, wet, rainy weather for conidia to infect host plants. This environmental requirement and narrow host range may limit the ability of the pathogen to fully establish and spread under dry field conditions.

Evaluate if the pest would have suitable hosts and climate to establish in California.

Score: 2

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Presently, the host range is limited to Camellia sinensis, C. oleifera, Cirsium japonicum, and Castanea sativa.

Evaluate the host range of the pest.

Score: 1

Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Colletotrichum henanense has high reproductive potential and conidia are produced successively.  They are transmitted by wind, wind-driven rain, cultivation tools, and human contact, however, conidial germination and plant infection require long, wet periods.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Anthracnose-infected chestnut and camellia plants may result in lower crop value and market loss.  Nursery productions of Camellia and chestnut are particularly at risk as nursery conditions are often conducive to infection by Colletotrichum  In open fields, disease development may be sporadic as it is affected by levels of pathogen inoculum and environmental conditions. Its economic impact is evaluated as a Medium risk.

Evaluate the economic impact of the pest to California using the criteria below.

Score: B, C

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Chestnut trees cultivated and growing in open environments in California are not expected to be significantly affected by Colletotrichum henanense due to the high moisture conditions required for the development of the pathogen.  However, under humid and moist environments, the pathogen may be more of a problem particularly in ornamental plantings of Camellia in home/urban and private/public settings.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Colletotrichum henanense10

Add up the total score and include it here.

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

 Evaluation is ‘Not Established’

 Score (0). Colletotrichum henanense is not known to be established in California and is known only from its detected in an intercepted shipment of chestnut.

Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 10.

Uncertainty:

None.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for the anthracnose pathogen, Colletotrichum henanense, is B.


References:

 De Silva, D. D., P. K. Ades, P. W. Crous and P. W. J. Taylor.  2017.  Colletotrichum species associated with chili anthracnose in Australia.  Plant Pathology 66 (2): 254-267.

Farr, D. F., and A. Y. Rossman. Fungal Databases, U.S. National Fungus Collections, ARS, USDA. Retrieved March 16, 2018, from https://nt.ars-grin.gov/fungaldatabases/

Li, H., G. Y. Zhou, X. Y. Qi and S. Q. Jiang.  2018.  First report of Colletotrichum henanense causing anthracnose on tea-oil trees in China.  Plant Disease “First Look” paper, accepted for publication, posted 01/03/2018. https://doi.org/10.1094/PDIS-08-17-1302-PDN 

Liu, F., Weir, B.S., Damm, U., Crous, P.W., Wang, Y., Liu, B., Wang, M., Zhang, M., and Cai, L. 2015. Unravelling Colletotrichum species associated with Camellia: employing ApMat and GS loci to resolve species in the C. gloeosporioides complex. Persoonia 35: 63-86.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

4/6/18 – 5/21/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


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Pest Rating: B

 


Posted by ls 

Citrus Leaf Blotch Virus

    California Pest Rating for
Citrus leaf blotch virus
Pest Rating: B

 


PEST RATING PROFILE

Initiating Event:

On February 26, 2018, Dr. G. Vidalakis, University of California, Director, Citrus Clonal Protection Program, informed CDFA of his detection of Citrus leaf blotch virus (CLBV) from a Bearss Lime tree at a residence in Los Angeles County.  Subsequently, an official sample, which comprised a total of 4 subsamples, was collected by the CDFA from the same Bearss Lime tree and sent to the CDFA Plant Pathology Laboratory for diagnosis. On February 27, 2018, Tongyan Tian, CDFA Plant Pathologist, detected Citrus leaf blotch virus from all four subsamples using RT-qPCR and further confirmed the identity of the pathogen by conventional RT-PCR and sequencing. A temporary Q rating was assigned to the pathogen.  The status, risk and consequences of introduction of CLBV to California are assessed and a pest permanent pest rating is proposed herein.

History & Status:

Background: In 1968, Dweet mottle virus (DMV) was initially detected and reported from Riverside, California, during re-indexing of a candidate Cleopatra mandarin variety (C. reticulata) on ‘Dweet’ tangor at the University of California Riverside Citrus Variety Improvement Program, the forerunner of the present Citrus Clonal Protection Program (CCPP).  The candidate mandarin variety had been introduced from Florida into the Program at Riverside.  The virus produced leaf chlorotic blotching symptoms that resembled, but were distinct from, symptoms produced by psorosis virus and Citrus concave gum virus.  It also produced a mild exocortis reaction in Etrog citron.  The parent tree did not show symptoms of damage caused by any known virus and the trunk appeared normal without any signs of stem pitting or bark discoloration, although small fruit, twig dieback and little new growth were apparent.  Since the virus produced symptoms only in ‘Dweet’, it was named Dweet mottle virus (Roistacher & Blue, 1968). However, Dweet mottle virus was not reported from any commercial citrus production sites nor was it observed to produce any economic losses and was detected only once after 1963 in the CCPP indexing program (Krueger et al., 2012).

Then in 1984, at the Citrus Variety Improvement Program in Spain, Navarro and other scientists reported a new graft transmissible disease that caused a bud-union incompatibility between ‘Nagami’ kumquat and ‘Troyer’ citrange rootstock. The ‘Nagami’ kumquat had been introduced from Corsica, France.  In addition to bud-union incompatibility, the presumptive virus involved caused vein clearing in certain citrus species and stem pitting in Etrog citron.  However, after shoot-tip grafting, some plants produced were compatible with Troyer, but still caused stem pitting in Etrog citron, thereby, indicating the involvement of more than one virus (Navarro et al., 1984). Galipienso et al., 2000, gave further evidence of the involvement of more than one virus by demonstrating bud union crease in certain citrus species but not others when propagated on ‘Troyer’ citrange. However, chlorotic blotching in ‘Dweet’ tangor, like those induced by DMV, and stem pitting in Etrog citron were produced by all sources of the virus.  In 2001-02, the causal agent in “Nagami’ kumquat was partially purified and characterized and given the candidate name, Citrus leaf blotch virus (CLBV) (Galipienso et al., 2001; Vives et al., 2001, 2002).  Furthermore, these researchers detected CLBV in different citrus varieties from Japan, New South Wales (Australia), Spain, and Florida, usually associated with abnormal bud union on citrange or citrumelo. Comparison of 14 CLBV isolates from Spain, Japan, USA, France and Australia showed low genetic diversity (Vives et al., 2002).  Low rates of seed transmission were demonstrated in three citrus varieties or hybrids (Guerri et al., 2004).     A few years later, Vives et al., (2005) conducted partial sequence analysis to show that Dweet mottle virus from California had over 96% sequence (high) homology with citrus leaf blotch virus from Spain and therefore, suggested that DMV may be caused by CLBV.  Both viruses induce mottling in ‘Dweet’ tangor and stem pitting in ‘Etrog’ citron and that, besides CLBV, a different pathogen causing bud-union crease and vein clearing may be present in ‘Nagami’ kumquat sources but not in DMV from California source.  This was further demonstrated by Vives et al., (2008a) by the development of full-genome cDNA clones of CLBV that caused systemic infection in agro-inoculated herbaceous and citrus host plants and induced chlorotic blotching in ‘Dweet’ tangor and stem pitting in Etrog citron, but not vein clearing in Pineapple sweet orange or bud union crease on trifoliate rootstocks.  Then in 2010, Hajeri and other researchers at the University of California, Riverside, and the USDA ARS National Clonal Germplasm Repository for Citrus and Dates (NCGRCD), Riverside, determined the complete nucleotide sequence of DMV and with phylogenetic analysis showed that DMV is an isolate of CLBV, and not a distinct species, within the genus Citrivirus.

In California, the seed transmissibility of citrus leaf blotch virus caused concern to the citrus nursery industry.  Consequently, Kreuger et al. (2012) reported that all citrus trees at CCPP and NCGRCD were tested for the presence of the virus using RT-PCR with local DMV positives and a CLBV positive from Florida as positive controls. The virus was not detected in the tested trees.  Furthermore, they failed to detect it during surveys of field trees exhibiting bud union abnormalities for the presence of specific pathogens and therefore, while the overall status of CLBV in California is presently unknown, they believe that this virus if present at all, is only at a low incidence.  This is because the close identity of CLBV and DMV has likely prevented CLBV from becoming introduced into California.  All introductions of new citrus germplasm are indexed into ‘Dweet’ tangor as well as other indicator species at CCPP and NCGRCD. Reaction of CLBV in ‘Dweet’ tangor would enable detection of this virus, even if the actual identity of the virus was not known at the time of indexing. Detection of positives or even misidentifications would have been eliminated by thermal therapy or shoot-tip grafting before release (Kreuger et al., 2005, 2012).

Citrus leaf blotch virus has been reported in China, Corsica (France), Cuba, Italy, Japan, New South Wales (Australia), New Zealand, Spain, Florida, Arkansas, Oregon, and California (USA).  In Arkansas and Oregon, the virus was found in peony plants showing stunting and gnarled irregularities, however, since the virus was found in both symptomatic and asymptomatic material, it could not be associated with the disease and its role in peony health is currently unknown.  Nonetheless, CLBV may easily move between propagation cycles via mechanical and seed transmission of clonally propagated peony plants (Gress et al., 2017).

Citrus leaf blotch virus not only causes symptomless infection in most citrus but also, is unevenly distributed within an infected plant, thereby presenting a possible challenge for its detection. In greenhouse studies, Vives et al. (2002) detected CLBV consistently in young leaves of infected ‘Nagami’ kumquat, ‘Owari’ Satsuma, Navelina and Navel oranges, however, detection in old leaves of other citrus species (Eureka lemon, Marsh grapefruit and Nules Clementine) was not consistent, particularly in Pineapple sweet orange.  Detection of the virus in field trees was even less consistent, and not detected in neighbor trees showing similar symptoms possibly due to low titer or uneven distribution of the virus in the plant.

HostsCitrus spp., including C. sinensis, C. limon, C. unshiu, C. paradisi, Poncirus trifoliata, P. trifoliata x C. sinensis (Harper et al., 2008), C. medica (Etrog citrus), C. reticulata x C. sinensis (‘Dweet’ tangor) (Roistacher & Blue, 1968), Fortunella margarita (kumquat “Nagami’) (Navarro et al., 1984), Prunus avium cv. Red-lamp (sweet cherry) (Wang et al., 2016), Actinidia sp. (kiwifruit) (Zhu et al., 2016), Paeonia lactiflora (peony) (Gress et al., 2017).  Experimental hosts include Nicotiana cavicola (Guardo et al., 2009), N. occidentalis and N. benthamiana (Vives et al., 2008b).

Symptoms: Citrus leaf blotch virus causes symptomless infection in most citrus species and cultivars (Vives et al., 2008a).  However, CLBV (and the isolate, DMV) induce chlorotic blotching or mottling in ‘Dweet’ tangor and stem pitting ‘Etrog’ citron. Although CLBV does not induce bud union crease on trifoliate rootstock (Vives et al., 2008a), it has been found to be usually associated with abnormal bud union on citrange or citrumelo rootstock. A different pathogen or interaction of CLBV with a different pathogen is likely the cause of bud union crease and vein clearing symptoms (Vives et al., 2005).

Damage Potential: Citrus leaf blotch virus causes chlorotic leaf blotching in ‘Dweet’ tangor and stem pitting in Etrog citron.  Although it does not induce bud union crease in several citrus species it is usually associated with bud union crease symptoms in citrange and citrumelo rootstocks and therefore, an interaction between CLBV and other agent(s) cannot be ruled out.  There are no reports of yield losses due to CLBV and the virus can cause symptomless infections in most citrus species and cultivars. In California, CLBV (aka DMV) is a regulated pathogen and its distribution is unknown or at best likely to be of low incidence. CLBV (aka DMV) was not reported from any commercial citrus production sites in California nor was it observed to produce any economic losses (Krueger et al., 2012).  However, in certain scion-rootstock combinations using ‘Dweet’ tangor and Etrog citron rootstocks there may be a potential for disease development due to CLBV.

TransmissionCitrus leaf blotch virus is transmitted in citrus by grafting and seed.  CLBV dispersal occurs primarily by propagation of infected buds.  Low rates of seed transmission in at least three citrus species and hybrid, ‘Troyer’ citrange (Citrus sinensis x Poncirus trifoliata), ‘Nagami’ kumquat (Fortunella margarita) and sour orange (C. aurantium), has been demonstrated (Guerri et al., 2004).  Also, CLBV has been mechanically transmitted to Nicotiana cavicola (Guardo et al., 2009), by sap inoculation to N. occidentalis and N. benthamiana (Vives et al., 2008b), and transmitted from citrus to citrus by contaminated knife blades (Roistacher et al., 1980).  The virus is not transmitted by vectors (Galipienso et al., 2000).

Worldwide Distribution: Asia: China, Japan; Europe: Italy, Spain; North America: USA, Cuba; Oceania: New South Wales (Australia), New Zealand (Cao et al., 2017; Gress et al., 2017; Guardo et al., 2007; Harper et al., 2008; Hernández-Rodríguez, 2016; Navarro et al., 1984; Roistacher & Blue, 1968; Vives et al., 2002; Wang et al., 2016).

Official Control: Citrus leaf blotch virus is on the ‘Harmful Organism’ list for Uruguay (USDA PCIT, 2018).  CLBV (aka DMV) is a regulated pathogen in California’s mandatory Citrus Nursery Stock Pest Cleanliness Program (CCR, Title 3, Division 4, Chapter 4, Subchapter 6, Section 3701).

California Distribution: The distribution in California is unknown.  If at all present, it is likely to be only at a low incidence (Kreuger et al., 2005, 2012.  See: ‘Background’).

California Interceptions: No official interceptions have been reported.

The risk Citrus leaf blotch virus would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Although the distribution of Citrus leaf blotch virus in California, is presently unknown and is likely to be only at a low incidence (Kreuger et al., 2012), if not regulated, it may be possible for the pathogen to have a widespread establishment in symptomatic and non-symptomatic infected citrus varieties in commercial citrus-growing regions of the State.

Evaluate if the pest would have suitable hosts and climate to establish in California.  Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: The natural host range is limited primarily to Citrus  Other hosts include sweet cherry and kiwifruit reported from China and peony reported from Arkansas and Oregon. Experimental hosts include, Nicotiana cavicola, N. occidentalis and N. benthamiana.

Evaluate the host range of the pest.

Score: 1

Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Citrus leaf blotch virus has high reproduction within its plant host, although unevenly distributed within infected plants. It is transmitted by grafting, seed, and mechanically. Its ability for long distance spread through infected seed render it a high rating for dispersal.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Citrus leaf blotch virus is a regulated pathogen under California’s mandatory Citrus Nursery Stock Pest Cleanliness Program.  Under this program any citrus stock found positive for the pathogen would be eliminated before release for commercial planting.  This pathogen causes chlorotic leaf blotching in ‘Dweet’ tangor and stem pitting in Etrog citron.  Although it does not induce bud union crease in several citrus species, it is usually associated with bud union crease symptoms in citrange and citrumelo rootstocks and therefore, an interaction between CLBV and other agent(s) cannot be ruled out.  There are no reports of yield losses due to CLBV and the virus can cause symptomless infections in most citrus species and cultivars. Researchers have stated that CLBV has not been reported from commercial citrus production sites in California nor was it observed to cause any economic losses.  If citrus stock were not regulated, it is likely that in certain scion-rootstock combinations using ‘Dweet’ tangor and Etrog citron rootstocks there may be a potential for disease development due to CLBV. In such a case, it is estimated that CLBV could lower crop yield and value and trigger the loss of markets.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, B, C

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: No environmental impact is expected, however, if not regulated, CLBV may impact home/urban plantings of citrus host plants.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E.  The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact. Score: 2

– Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Citrus leaf blotch virus: 12

Add up the total score and include it here. (Score)

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included. (Score)

Evaluation is (0). While the distribution of CLBV in California is currently not known, there is no evidence that it is established within the State.

Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 12   

Uncertainty:

The in-state distribution of CLBV is not currently known.  Also, the impact of infection related to crop damage and losses is not known.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Citrus leaf blotch virus is B.


References:

Cao, M. J., Y. -Q. Yu, X. Tian, F. Y. Y. and, R. H. Li and C. Y. Zhou.  2017.  First report of Citrus leaf blotch in lemon in China.  Plant Disease 101: 8.  https://doi.org/10.1094/PDIS-10-16-1500-PDN

Galipienso, L., L. Navarro, J. F. Ballester-Olmos, J. Pina, P. Moreno, and J. Guerri.  2000.  Host range and symptomatology of a graft transmissible pathogen causing bud union crease of citrus on trifoliate rootstocks. Plant Pathology 49: 308–314.

Galipienso, L., M. C. Vives, P. Moreno, R. G. Milne, L. Navarro and J. Guerri.  2001.  Partial characterization of Citrus leaf blotch virus, a new virus from Nagami kumquat.  Archives of Virology 146: 357–368.

Gress, J. C., S. Smith, and I. E. Tzanetakis.  2017.  First report of Citrus leaf blotch virus in peony in the U.S.A. Plant Disease 101: 637. https://doi.org/10.1094/PDIS-08-16-1218-PDN

Guardo, M., G Sorrentino, T. Marletta and A. Carusa.  2007.  First report of Citrus leaf blotch on kumquat in ItalyPlant Disease 91: 104.

Guardo, M., O. Potere, M. A. Castellano, V. Savino and A. Caruso.  2009.  A new herbaceous host for Citrus leaf blotch virus. Journal of Plant Pathology 91: 485-488.

Guardo, M., G. Sorrentino and A. Caruso.  2015.  Characterization and incidence of Citrus leaf blotch virus in Southern Italy.  12th International Citrus Congress – International Society of Citriculture. Acta Horticulturae 1065: 825-83.

Hajeri, S., C. Ramadugu, M. Keremane, G. Vidalakis and R. Lee.  2010.  Nucleotide sequence and genome organization of Dweet mottle virus and its relationship to members of the family Betaflexiviridae.  Arch Virol 15: 1523-1527.  DOI 10.1007/s00705-010-0758-1

Harper, S. J., K. M. Chooi and M. N. Pearson.  2008.  First report of Citrus leaf blotch virus in New Zealand.  Plant Disease 92: 1470.  https://doi.org/10.1094/PDIS-92-10-1470C

Hernàndez-Rodríguez, L., J. M. Pérez-Castro, G. García-García, P. Luis Ramos-González, V. Zamora-Rodríguez, Xenia Ferriol-Marchena, Inés Peña-Bárzaga and L. Batista-Le Riverend.  2016.  Citrus leaf blotch in Cuba: first report and partial molecular characterization.  Tropical Plant Pathology 41: 147. https://doi.org/10.1007/s40858-016-0078-4

Krueger, R. R., J. A. Bash and R. F. Lee.  2005.  Phytosanitary status of California citrus.  International Organization of Citrus Virologists Conference Proceedings (1957-20), 16 (16): 468-472.  https://escholarship.org/uc/item/3667q9qn

Krueger, R. R., J. A. Bash and R. F. Lee.  2012.  Dweet mottle virus and Citrus leaf blotch virus.  http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=7112

Navarro, L., J. A. Pina, J. F. Ballester-Olmos, P. Moreno and M. Cambra.  1984.  A new graft transmissible disease found in Nagami kumquat. In: Timmer L. W., and J. A. Dodds (eds) Proceedings of the 9th Conference of the International Organization of Citrus Virologists, IOCV, Riverside, pp 234–240.

Roistacher, C. N., and R. L. Blue.  1968.  A psorosis-like virus causing symptoms only on ‘Dweet’ tangor.  International Organization of Citrus Virologists Conference Proceedings (1957-2010), 4(4): 13-18.

Roistacher, C. N., E. M. Nauer and R. C. Wagner.  1980.  Transmissibility of cachexia, Dweet mottle, psorosis and infectious variegation viruses on knife blades and its prevention.  Proceedings of the 8th Conference of the International Organization of Citrus Virologists, IOCV, Riverside 1980: 225-229.

USDA PCIT.  2018. USDA Phytosanitary Certificate Issuance & Tracking System. Retrieved March 15, 2018. 3:25:54 pm CDT.  https://pcit.aphis.usda.gov/PExD/faces/ReportHarmOrgs.jsp.

Vives, M. C., L. Galipienso, L. Navarro, P. Moreno and J. Guerri.  2001.  The nucleotide sequence and genomic organization of Citrus leaf blotch virus: Candidate type species for a new virus genus.  Virology 287: 225-233.

Vives, M. C., L. Galipienso, L. Navarro, P. Moreno and J. Guerri.  2002.  Citrus leaf blotch virus: a new citrus virus associated with bud union crease on trifoliate rootstocks.  International Organization of Citrus Virologists Conference Proceedings (1957-2010), 15 (15): 205-212.

Vives, M. C., L. Rubio, L. Galipienso, L. Navarro, P. Moreno and J. Guerri.  2002.  Low genetic variation between isolates of Citrus leaf blotch virus from different host species and different geographical origins. Journal of General Virology 83: 2587–2591.

Vives M. C., J. A. Pina, J. Juarez, L. Navarro, P. Moreno and J. Guerri.  2005.  Dweet mottle disease is probably caused by Citrus leaf blotch virus. 16th Conference of the International Organization of Citrus Virologists Conference Proceedings (1957-2010), 15 (16): 251-256.

Vives, M. C., S. Martin, S. Ambros, A. Renovell, L. Navarro, J. A. Pina, P. Moreno, J. and J. Guerri.  2008a.  Development of a full-genome cDNA clone of Citrus leaf blotch virus and infection of citrus plants. Molecular Plant Pathology 9:787–797.

Vives, M. C., P. Moreno, L. Navarro and J. Guerri.  2008b.  Citrus leaf blotch virus.  In: Rao, G. P., A. Myrta and K. Ling (eds).  Characterization, Diagnosis and Management of Plant Viruses, vol. 2. Pp. 55-67.  Studium Press, Houston, TX, USA.

Wang, J., D. Zhu, Y. Tan, X. Zong, H. Wei and Q. Liu.  2016. First report of Citrus leaf blotch virus in sweet cherry.  Plant Disease 100:1027.

Zhu, Chen-xi, Wang, Guo-ping, Zheng, Ya-zhou, Yang, Zuo-kun, Wang, Li-ping, Xu, Wen-xing and N. Hong.  2016.  RT-PCR detection and sequence analysis of coat protein gene of Citrus leaf blotch virus infecting kiwifruit trees.  Acta Phytopathologica Sinica, 46 (1): 11.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


Comment Period:* CLOSED

4/6/18 – 5/21/18


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:
Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.


Pest Rating: B

 


Posted by ls 

Banded Wood Snail | Cepaea nemoralis

BANDED WOOD SNAIL
California Pest Rating for
Banded Wood Snail  |  Cepaea nemoralis
Gastropoda: Helicidae  
Pest Rating: A

PEST RATING PROFILE
Initiating Event:

Cepaea nemoralis is frequently intercepted by CDFA. A pest rating proposal is required to support its permanent pest rating.

History & Status:

Background: Cepaea nemoralis, known as the banded wood snail, is the most common species of land snail in Europe and has been introduced to North America. This snail is commonly found in urban areas, where it inhabits gardens and abandoned lots. They feed on dead and living plant material, carrion, fungi, moss, and insects1.

          Cepaea nemoralis has a yellow, pink, or brown shell. The shell contains five dark bands. Banded wood snails are hermaphrodites, but cross fertilization occurs (each snail fertilizes the other). They often mate multiple times prior to egg-laying and can store sperm for up to 15 months. Eggs are buried in moist soil, hatching after about three weeks. The snails reach maturity in four years and may live as  long as five to nine years 1, 4.

Worldwide Distribution: Banded wood snails are distributed throughout much of Europe, extending to Poland.  This snail was introduced into North America during the nineteenth century, and it is currently found in Virginia, New York, Ontario, and Massachusetts1, 2.

Official Control: Banded wood snail is listed as a harmful organism in Canada, Israel, Japan, and Taiwan6.

California Distribution: Banded wood snails have never been found in the environment of California.

California Interceptions: Between January 2000 and August 2017, banded wood snails have been intercepted 20 times.  These interceptions include border station inspections and high risk pest exclusion activities.

The risk Cepaea nemoralis (Banded wood snail) would pose to California is evaluated below.

Consequences of Introduction:
  1. Climate/Host Interaction: Banded wood snails can feed on a variety of live and dead plants and dead animals and insects, including remains of ants, beetles, spiders, mites, springtails, and aphids. Banded wood snails may establish in larger, but limited, warm agricultural and metropolitan areas of California. It receives a Medium (2) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

  • Low (1) Not likely to establish in California; or likely to establish in very limited areas.
  •  Medium (2) may be able to establish in a larger but limited part of California.
  • High (3) likely to establish a widespread distribution in California.

2. Known Pest Host Range: Banded wood snails are highly polyphagous and are known to feed on a wide variety of live and dead plants and animals. It receives a High (3) in this category.

Evaluate the host range of the pest.

  • Low (1) has a very limited host range.
  • Medium (2) has a moderate host range.
  • High (3) has a wide host range.

3. Pest Dispersal Potential: Banded wood snails are obligately outcrossing hermaphrodites, with both individuals exchanging sperm during mating, and both individuals able to lay eggs afterward. On average, they lay 30-80 eggs that hatch in 15-20 days. Breeding takes place from April through October. The snail’s foot is used to create a cavity in the soil where the eggs are deposited1, 4. It receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest.

  • Low (1) does not have high reproductive or dispersal potential.
  • Medium (2) has either high reproductive or dispersal potential.
  • High (3) has both high reproduction and dispersal potential

4. Economic Impact: The banded wood snail is not expected to lower crop yields. It could reduce the value of nursery stock by disfiguring plants with its presence and increase crop production costs in nurseries and orchards. The banded wood snail is a potential vector of Angiostrongylus vasorum, the French heartworm (a disease of wild and domestic canids) 3. It receives a High (3) in this category. Economic Impact: B, C, E: Environmental Score: 3

Evaluate the economic impact of the pest to California using the criteria below.

A. The pest could lower crop yield.
B. The pest could lower crop value (includes increasing crop production costs).
C. The pest could trigger the loss of markets (includes quarantines).
D. The pest could negatively change normal cultural practices.
E. The pest can vector, or is vectored, by another pestiferous organism.
F. The organism is injurious or poisonous to agriculturally important animals.
G. The organism can interfere with the delivery or supply of water for agricultural uses.

  • Low (1) causes 0 or 1 of these impacts.
  • Medium (2) causes 2 of these impacts.
  • High (3) causes 3 or more of these impacts.

5. Environmental Impact: If introduced, the banded wood snail is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It might trigger new chemical treatments in orchards and nurseries and by residents who find infested plants unsightly. It is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. It receives a Medium (2) in this category.

Environmental Impact: A, D:  Environmental Impact: Score: 2

Evaluate the environmental impact of the pest on California using the criteria below.

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.
B. The pest could directly affect threatened or endangered species.
C. The pest could impact threatened or endangered species by disrupting critical habitats.
D. The pest could trigger additional official or private treatment programs.
E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

  • Low (1) causes none of the above to occur.
  • Medium (2) causes one of the above to occur.
  • High (3) causes two or more of the above to occur.
Consequences of Introduction to California for Cepaea nemoralis(Banded wood snails): High (13) 
  • Low = 5-8 points
  • Medium = 9-12 points
  • High = 13-15 points

Post Entry Distribution and Survey Information: The banded wood snail has never been found in the environment in California and receives a Not Established (0) in this category

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Not established (0) Pest never detected in California, or known only from incursions.
Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).
Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.
 High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (13)

Uncertainty:

Banded wood snails are commonly intercepted. There have been no formal surveys for this snail in the state. It is therefore possible that it could be present in some locations in California. 

Conclusion and Rating Justification:

Banded wood snail is not known to occur in California and might cause significant economic and environmental impacts if it were to become established here. Currently, an “A” rating is justified.

References:
  1. Animal Diversity Web. Accessed September 7, 2017. http://animaldiversity.org/accounts/Cepaea_nemoralis/

2. Encyclopedia of Life. Accessed September 7, 2017.
http://eol.org/pages/449909/details#overview

3. G.A. Conboy. 2000. Canine Angiostrongylosis (French Heartworm). Accessed September 7, 2017.
http://www.ivis.org/advances/Parasit_Bowman/conboy_angiostrongylosis/ivis.pdf

4. Maggie Whitson. 2005. Journal of the Kentucky Academy of Science, 66(2):82-88. Accessed September 7, 2017. 
http://stoppinginvasives.com/dotAsset/e2bbc1b0-81c5-42b1-b9e4-8123952c6c02.pdf

5. Pest and Damage Record Database, California Department of Food and   Agriculture, Plant Health and Pest Prevention Services.
http://phpps.cdfa.ca.gov/user/frmLogon2.asp

6. USDA phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed September 7, 2017.
https://pcit.aphis.usda.gov/pcit/


Author:

Javaid Iqbal,  California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Responsible Party:

Jason Leathers; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 654-1211; plant.health[@]cdfa.ca.gov.


Comment Period:*CLOSED

11/7/17 – 12/22/17


Pest Rating: A


Posted by dk

Alligatorweed | Alternanthera philoxeroides

California Pest Rating for
white flower with green leaves
Alligatorweed | Alternanthera philoxeroides
Family:  Amaranthaceae
Pest Rating: A | Proposed Seed Rating: R

PEST RATING PROFILE
Initiating Event:

There was a recent find of alligatorweed in Solano County; this is the first detection in northern California in many years.

History & Status:

Background: Alligatorweed is a perennial herb with horizontal to ascending stems to 1 m long, rooting at the nodes. The flowers are small and borne in small heads with white floral bracts. Like many aquatic emergent, it has distinctive submerged and emersed forms. The submerged form has hollow, floating, emergent and submerged stems. Terrestrial plants have solid stems. Typically, plants grow rooted in soil in shallow water and form dense, interwoven floating mats that extend over the surface of deeper water. Mats can become quite dense and nearly impenetrable. The floating mats can break away and follow currents to colonize new sites. Mats disrupt the natural ecology of a site by reducing light penetration and crowding out native species. Serious infestations can create anoxic, disease-promoting, and mosquito-breeding conditions.

Worldwide Distribution: This weed is found in wet, disturbed areas. It is also a weed of rice and sugar cane fields in tropical and subtropical regions. Native to southern Asia, alligatorweed is now found in tropical and subtropical regions around the world. It is considered an invasive species in Australia, China, New Zealand, and Thailand. Alligatorweed has been introduced throughout the southeastern United States from Virginia to Texas.

Official Control: Alligatorweed has had a CDFA rating of A as a pest in California for decades. The population in Los Angeles County has been managed intermittently over the years by the county, but it still persists.  It has official status as a weed in Alabama, Arizona, Arkansas, California, Florida, South Carolina, and Texas.

California Distribution:  Alligatorweed occurs in several southern California counties. It also has been detected in Contra Costa and Kings Counties, where it is eradicated. There was a recent find of 2 colonies in southern Solano County.

California Interceptions: Alligatorweed has been sent to CDFA by land managers.

The risk Alternanthera philoxeroides (alligatorweed) poses to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Risk is Medium (2), as the plant occurs in wetlands such as the Delta and creeks and rivers, as well as irrigation canals and watering ponds. These habitats are limited but widely distributed in California.

Evaluate if the pest would have suitable hosts and climate to establish in California:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Most plants do not require any one host, but grow wherever ecological conditions are favorable. It receives a High (3) in this category.

Evaluate the host range of the pest.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

High (3) has a wide host range.

3) Pest Dispersal Potential: Risk is Medium (2). Alligatorweed can spread rapidly via water movement and on boats and equipment as stem fragments. It is also grown as an aquarium plant and occasionally discarded into waterways. Seeds evidently are not produced in the United States.

Evaluate the natural and artificial dispersal potential of the pest.

– Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Risk is High (3), as the plant can lower crop yields in rice fields, trigger state or international quarantines, and force changes in cultural practices by blocking canals. It has spread widely in the southeast, and has proven difficult to eradicate both there and in California. Its mats can improve habitat for mosquito larvae, leading to larger mosquito populations.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, C, D, E, G

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: Risk is High (3) as alligatorweed could further invade the water systems of California, disrupt natural wetland communities and potentially lower biodiversity by invading wetlands. The dense growth impedes water movement, blocks the growth of native plants, and reduces available habitat for water birds and fish. Its invasion in the Delta and its tributaries could degrade habitat of rare species such as Mason’s lilaeopsis (Lilaeopsis masonii), Sacramento River Chinook salmon (Oncorhynchus tshawytscha),  and Giant garter snake (Thamnophis gigas).  Its presence would trigger additional control measures.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Alternanthera philoxeroides (alligatorweed) : High (13)

-Low = 5-8 points

-Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: Alligatorweed currently is known from 3-4 populations in northern and southern California. It receives a Medium (-2) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: -2

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (11)

Uncertainty:

Uncertainty is low, as alligatorweed has established in wetlands in California and other states. There is some uncertainty as to the actual distribution of this plant in California, as, like some other aquatic weeds, it is likely to be overlooked.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above:

Proposed Rating: Despite its limited ability to disperse between watersheds, this is a potentially significant weed in California of both natural wetlands and irrigation canals. Because of its potential economic impacts, it deserves an A rating, as it has proven tenacious and is actively spreading.

References:

Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. The Jepson manual: vascular plants of California, second edition. University of California Press, Berkeley.

Consortium of California Herbaria. Accessed 10/3/2017:  ucjeps.berkeley.edu/consortium/

Florida Dept of Agriculture Weed of the Month: Alternanthera sessilis. Accessed 10/3/2017: http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Plant-Industry-Publications/Weed-of-the-Month/April-2011-Alternanthera-Sessilis

Invasive Plant Atlas of the Mid-South. alligatorweed. Accessed 10/3/2017:    https://www.gri.msstate.edu/ipams/species.php?CName=Alligatorweed


Responsible Party:

Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6650. plant.health[@]cdfa.ca.gov.


Comment Period: CLOSED

10/17/17 – 12/1/17*


*NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Pest Rating: A | Proposed Seed Rating: R


Posted by ls

Nutria | Myocastor coypus

California Pest Rating for
Nutria  |  Myocastor coypus
Pest Rating: A

PEST RATING PROFILE
Initiating Event

On March 30, 2017 a suspected Nutria (Myocastor coypus) was turned in to California Department of Fish and Wildlife staff in Merced County. It was confirmed by the local Department of Fish and Wildlife Services trapper.  The animal was found living in a managed wetland (duck hunting club) adjacent to the Grasslands Ecological Area in Merced County.

History & Status

Background

Nutria are large aquatic rodents that may easily be confused with the even larger North American Beaver (Castor Canadensis). Their long rat-like tail is the primary distinguishing characteristic when compared to the large paddle shaped tail of the beaver. Nutria are herbivores that may consume up to 25% of their body-weight per day, in addition they are wasteful feeders focusing on roots and tubers while discarding up to 90% of the plant matter they harvest. They may impact crops and landscape plantings in areas adjacent to water ways, damage water conveyance and storage structures, undermine roads and vector parasites and diseases to humans and livestock. Nutria are primarily nocturnal, though lack of predatory pressure or the influence of human feeding may cause an increase in daytime activity. Nutria are prolific breeders, females may have 2-3 liters per year with an average of 4-5 offspring per liter. Young become sexually active between four and six months of age. Nutria nest in dense vegetation and construct burrows for protection from cold temperatures. Burrows can range from 6-45 meters in length. Nutria have been found to cause significant damage to wetland and riparian habitats and are considered agricultural pests in many parts of the world. In the early 1900’s they were purposefully introduced in many parts of the world to supplement the trapping of furbearing animals for the fur trade. In nature, their populations are primarily limited by harsh winters, commercial trapping and large predators such as alligators or large snakes. Nutria have successfully established in brackish estuarine waters around the United States, however they are not capable of natural immigration in to California with its mountains, deserts and coastline borders.

map for predicted suitable habitat
Figure 1. Geographical extent of predicted suitable nutria habitat (based on 2003 – 2007 mechanistic model) in the contiguous United States compared to the status of nutria populations by state. (Sheffels 2013)

Worldwide Distribution

Native to South America. Nutria are a common invasive species in the Southeastern United States. Blamed for significant impacts and loss of wetlands in the Mississippi Delta as well as the Chesapeake Bay. They are widespread in the Pacific Northwest, including Oregon, Washington and Southern British Columbia. Nutria have been successfully introduced and established in every continent other than Australia and Antarctica (Chesapeake Bay Nutria Eradication Project 2016).

Official Control:

A bounty system has been used in the past in Louisiana. During the 2009-2010 trapping season the state of Louisiana paid a $5 per animal bounty on 445,963 Nutria harvested for a total of $2,229,815 (Coastwide Nutria Control Program).

When necessary USDA – Wildlife Services will control localized populations of Nutria.  In 2002 an eradication program was initiated in the state of Maryland. As of 2016 all known populations had been removed from the Delmarva Peninsula of the Chesapeake Bay in Maryland. Surveillance is currently ongoing to verify eradication (Chesapeake Bay Nutria Eradication Project 2016).

Washington State requires any trapped Nutria to be immediately euthanized and prohibits their movement (Washington Invasive Species Council 2016).

Nutria are Considered an agricultural pest in China. Nutria eradication is underway in Japan. They are known to be responsible for damage to fish ponds in Israel. Nutria are considered a pest in Western Europe but a valuable resource in Eastern Europe where fur has higher value. England initiated a trapping eradication in 1981 and declared eradication in 1989. There are numerous Nutria eradication programs in France. They are considered a pest in Germany due to damage to dams. Nutria are also considered a pest of rice production in Italy. (Carter and Leonard 2002)

California Distribution:

There are historical reports of Nutria from Elizabeth Lake, Stanislaus River and Los Angeles County. The first introduction to the United States occurred at Elizabeth Lake California in 1899 which failed due to breeding failures. The California Department of Food and Agriculture conducted an eradication program for a feral population of Nutria from the Stanislaus River during the 1960’s. Eradication was achieved by 1978 (National Wetlands Research Center 2015).

Recent modeling of Nutria distribution and climate change predict that California is highly suitable for Nutria establishment and spread. The mountainous terrain and disconnected hydrological units are the only barrier between Northern California and the Nutria infested waterways of Southern Oregon (Jarnevich et al. 2017).

California Interceptions:

One adult Nutria was trapped in a managed wetland (duck hunting club) adjacent to the Grasslands Ecological Area in Merced County. There are anecdotal reports of additional Nutria sightings from the duck club caretaker.

Consequences of Introduction

The risk Nutria would pose to California is evaluated below.

Problems associated with high Nutria populations fall into several categories: destruction of marsh habitat, destruction of water control structures such as dykes and levees, destruction of agricultural crops, and the fact that the animals can serve as repositories of a variety of diseases.

1) Climate/Host Interaction: Evaluate if the pest would have suitable hosts and climate to establish in California. Score: 3

Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

Recent modeling data found that the majority of California could provide suitable habitat for Nutria. High elevations and deserts being the only limiting factors. Nutria could easily move throughout the inland waterways and irrigation networks.

2) Known Pest Host Range: Evaluate the host range of the pest. Score: 2

Low (1) has a very limited host range.

Medium (2) has a moderate host range.

High (3) has a wide host range.

Nutria are an aquatic species. Distribution would be limited to areas adjacent to waterways. Rivers, streams, estuaries and irrigation canals would all be suitable habitat. The interconnected waterways throughout the Sacramento-San Joaquin River and Delta and irrigated lands are all susceptible to Nutria establishment.

3) Pest Dispersal Potential: Evaluate the natural and artificial dispersal potential of the pest. Score: 3

Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

Nutria could naturally disperse throughout the entire Sacramento-San Joaquin Bay-Delta watershed which covers over 75,000 square miles from Tehachapi to the Cascades Mountain Range. They could also establish around natural and man-made lakes, reservoirs, irrigation canals and other waterbodies.

4) Economic Impact: Evaluate the likely economic impacts of the pest to California using the criteria below. Score: 3

Economic Impact: A, B, E, G

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

Nutria have shown to damage rice and orchards/vineyards potentially lowering crop yield and causing losses.  There is also potential for them to disrupt water delivery to crops and spread contaminants impacting food safety.  They are known to vector liver flukes and other parasites to livestock, damage water conveyance and storage infrastructure.

5) Environmental Impact: Evaluate the environmental impact of the pest on California using the criteria below. Score: 3

Environmental Impact: A, B, C, D, E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

High (3) causes two or more of the above to occur.

Nutria have contributed to massive wetland destruction and land loss. Nutria could feed directly on threatened or endangered wetland and riparian plants. Nutria have created eat-outs completely denuding vast areas of habitat, their burrowing activity also contributes to increased siltation of waterways which can impact fish habitat. Many areas of the United States currently have control and eradication programs targeting Nutria. In addition to being agricultural pests and damaging the environment Nutria have also impacted urban and residential landscaping, transmit parasites to animals and humans and become aggressive towards humans and pets.

Consequences of Introduction to California for Nutria:

Add up the total score and include it here. (14)

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included. (-1)

Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Nutria have successfully been eradicated from California in an area close to the current location of the detections. There is only one other documented introduction in 1899 which failed to establish. There are no PDR records of other encounters in the State.

Final Score

The final score is the consequences of introduction score minus the post entry distribution and survey information score: (13)

Uncertainty

It is important to separate out uncertainty from risk. Use this section to evaluate any uncertainty associated with the introduction of the pest to California.

The three primary limiting factors of Nutria populations are harsh winters, commercial trapping and large predator populations. California has very mild winters compared to other infested areas of the world. Fur trapping is a very insignificant activity in California due to social as well as regulatory constraints and low fur prices. California does not have large populations of predators nor predators large enough to effectively take Nutria. The Southeastern U.S. has alligators and the portions of Africa that have not been impacted have many different species of large carnivores.

Conclusion and Rating Justification

Proposed rating of A.

Nutria have proven to be a significant agricultural pest in other parts of the world with similar climates and cropping systems to California. Significantly impacted crops include rice, orchards and vineyards. In addition, Nutria are a known vector of ectoparasites and diseases. Livestock are particularly susceptible to liver flukes if exposed to water soiled by Nutria excrement (Menard et al.2000). Nutria have caused extensive damage to waterways, water storage and conveyance as well as adjacent rights-of-way. Of particular concern would be the thousands of miles of earthen canal, dikes and levees comprising much of the Central Valley irrigation infrastructure (Witmer et al. 2012).

Nutria have caused extreme environmental degradation to wetlands around the United States. Their feeding behavior can produce “eat outs” which eliminate the aquatic vegetation which contains wetland and marsh soils. The subsequent erosion is extremely damaging to wetlands. In addition, this erosion combined with their burrowing activity has the potential to damage fish habitat through increased siltation. In the Chesapeake Bay estuary one of the most heavily impacted habitat types is the Spartina sp. complex similar to much of the San Francisco Bay estuary.

Due to the documented negative impacts to agriculture and the environment of Nutria establishment and the high probability of eradication in California, a rating of A is justified.


References

Carter, Jacoby, and Billy P. Leonard. “A Review of the Literature on the Worldwide Distribution, Spread of, and Efforts to Eradicate the Coypu (Myocastor coypus).” Wildlife Society Bulletin (1973-2006), vol. 30, no. 1, 2002, pp. 162–175.  www.jstor.org/stable/3784650

Chesapeake Bay Nutria Eradication Project.  “U.S. Fish and Wildlife Service Species of Concern Fact Sheet: Nutria.” (2016) Aquatic Nuisance Species Task Force.  https://www.fws.gov/chesapeakenutriaproject/

Coastwide Nutria Control Program. “Home. Nutria Control Program” (2007) Louisiana Department of Wildlife and Fisheries.  http://www.nutria.com/site9.php

Jarnevich CS, Young NE, Sheffels TR, Carter J, Sytsma MD, Talbert C “Evaluating simplistic methods to understand current distributions and forecast distribution changes under climate change scenarios: an example with coypu (Myocastor coypus).” (2017) NeoBiota 32: 107-125. https://doi.org/10.3897/neobiota.32.8884

Menard A; M. L’Hostis, G. Leray, S. Marchandeau, M. Pascal, N. Roudot, V. Michel and A. Chauvin “Inventory of Wild Rodents and Lagomorphs as Natural Hosts of Fasciola hepatica on a Farm Located in a Humid Area in Loire Atlantique (France)” (2000), Parasite, 7, 77-82 http://dx.doi.org/10.1051/parasite/2000072077

National Wetlands Research Center. “Worldwide Distribution, Spread of, and Efforts to Eradicate the Nutria (Myocastor coypus).”(2015) United Stated Geological Survey (USGS). https://www.nwrc.usgs.gov/special/nutria/namerica.htm

Pasko, Susan and Anne Marie Eich, “Species of Concern Fact Sheet: Nutria” (2011) Aquatic Nuisance Species Task Force.  https://www.anstaskforce.gov/spoc/nutria.php

Sheffels, Trevor Robert, “Status of Nutria (Myocastor coypus) Populations in the Pacific Northwest and Development of Associated Control and Management Strategies, with an Emphasis on Metropolitan Habitats” (2013).Dissertations and Thesis.Paper 665. http://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1664&context=open_access_etds

Washington Invasive Species Council. “Stop the Invasion. Nutria, Myocastor coypus” (2016) Washington Department of Fish and Wildlife. http://www.invasivespecies.wa.gov/documents/priorities/NutriaFactSheet.pdf

Witmer, Gary; Sheffels, Trevor R.; and Kendrot, Stephen R., “The Introduction, Impacts, And Management of a Large, Invasive, Aquatic Rodent in The United States” (2012). USDA National Wildlife Research Center – Staff Publications. Paper 1215. http://digitalcommons.unl.edu/icwdm_usdanwrc/1215/


Responsible Party:

David Kratville, Senior Environmental Scientist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1102, plant.health[@]cdfa.ca.gov.


Comment Period: CLOSED

July 5, 2017 – August 19, 2017


NOTE:

You must be registered and logged in to post a comment.  If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.


Pest Rating: A


Posted by ls

Vertebrate Pests

Vertebrate pests are any species of mammal, bird, reptile, amphibian, or fish that causes damage to agricultural, natural, or industrial resources, or to any other resource, and to the public health or safety. Vertebrate pests cause millions of dollars in damage to agricultural crops, transportation infrastructure, water conveyance and restoration lands each year. Vertebrate pests threaten the public health and the environment as vectors of diseases that could be transmitted to humans, livestock and wildlife.


PEST RATINGS:

Nutria |  Myocastor coypus
Pest Rating:  A

Stemphylium solani G. F. Weber 1930

California Pest Rating for
Stemphylium solani G. F. Weber 1930
Pest Rating: A

 


PEST RATING PROFILE
Initiating Event:

On March 31, 2017, the CDFA Permits and Regulations Program requested a rating for Stemphylium solani.  Therefore, the associated risk and current status of S. solani in California are assessed here and a permanent rating is proposed.

History & Status:

Background:   Stemphylium solani is a fungal pathogen that causes Gray leaf spot disease in tomato, and Stemphylium leaf blight disease in cotton, garlic, and other hosts.  Gray leaf spot in tomato is actually caused by three species of Stemphylium, one being S. solani and the other two species: S. lycopersici (Enjoji) W. Yaman (syn. S. floridanum Hannon & G. F. Weber) and S. botryosum Wallr. f. sp. lycopersici Rotem, Y. Cohen, & I. Wahl.  Gray leaf spot is regarded one of the most destructive diseases of tomato in the southeastern United States and throughout the world wherever warm and humid conditions prevail (Jones & Pernezny, 2014).

Gray leaf spot disease has been reported from several countries worldwide including the United States (see ‘Worldwide Distribution’). In the United States, the disease was first observed in 1924 and by 1928 had spread throughout Florida causing widespread defoliation. Since then, the pathogen has been reported from several states but has never been reported from California.

Disease development:  The disease begins in infested seedbeds and transplant houses or field-transplanted seedlings, usually when the plants are in the first true-leaf stage of growth.  Cotyledons are not severely infected.   The pathogen is spread when infected seedlings are transplanted to fields.  Conidia (asexual spores) can be spread over extensive distances by wind. The teleomorph or sexual stage of S. solani is not known.  The disease is favored by warm temperatures (24-27°C) and high humidity. Spore germination and infection of plant are dependent on the presence of free moisture (dew or rain) (Jones & Pernezny, 2014).  Leaf wetness is considered more important than temperature in establishment of infection (Cerkauskas, 2005).  Stemphylium solani survives as a saprophyte on infected plant debris or on volunteer tomato, pepper, gladiolus, blue lupine, and other wild solanaceous plants.  In the southern state climates, the pathogen remains viable on tomato plants which are grown throughout the year (Jones & Pernezny, 2014).  The pathogen can be seedborne (Koike et al., 2007).

Dispersal and spread: Infected plants, seedlings, and plant debris.  Conidia may be wind-blown over extensive areas or by splashing water (Jones & Pernezny, 2014).

Hosts: Hosts of Stemphylium solani are included primarily in the plant family Solanaceae.  Numerous other plant families are also included with their associated hosts, including Amaryllidaceae (Allium sp.), Asteraceae (Lactuca sp.), and Malvaceae (Gossypium hirsutum).  Hosts include, Aegiceras corniculatum (black mangrove), Allium sativum (garlic), Aster sp. (aster), Basella rubra (Malabar spinach), Capsicum annuum (bell pepper), C. annuum var. annuum (cayenne pepper), C. frutescens (chili pepper), Carthamus sp. (distaff thistles), Cirsium sp. (thistle), Citrus sp. (citrus), Convolvulus arvensis (field bindweed), Cucumis sativus (cucumber), Dactylis glomerata (orchardgrass), Dianthus caryophyllus (carnation), Gossypium hirsutum (upland cotton), Ipomoea reptans (synonym: I. aquatica, swamp morning-glory), Kalanchoe blossfeldiana (flaming katy), Lactuca sativa (lettuce), Lupinus angustifolius (narrowleaf lupine), Lupinus sp. (lupine), Lycopersicon esculentum (synonym: L. lycopersicum, tomato), Lycopersicon sp., Pelargonium zonale (horse-shoe pelargonium), Physalis pubescens (husk tomato), Physalis sp. (groundcherry), Solanum gilo (gilo), S. lycocarpum (wolf apple), S. lycopersicum (garden tomato), S. melongena (aubergine/eggplant), S. melongena var. esculentum, S. pseudocapsicum (Jerusalem cherry), S. tuberosum (potato), Vicia faba (fava bean), Vigna sinensis (synonym: V. unguiculata, cowpea) (CABI, 2017; Farr & Rossman, 2017).

Symptoms:  Gray leaf spots or lesions are almost entirely limited to the leaf blades, but under favorable conditions, lesions may develop on petioles and on the more tender parts of growing stems.  Lesions on stems are linear and parallel to the stem.  Fruit symptoms have not been observed.  In infected tomatoes, symptoms of gray leaf spot are first exhibited as minute brownish-black specks on the lower leaves.  Randomly scattered circular to oblong spots develop on adaxial and abaxial leaf surfaces without being restricted by leaf veins.  The spots may be surrounded by a narrow yellow halo and enlarge to about 2.1 mm in diameter while individual spots on the base of leaves may enlarge to twice that size or more in diameter and occasionally coalesce, thereby, killing large portions of the leaf blade. As the spots enlarge, the centers turn gray, eventually dry, crack, and fall out.  Frequently, at this stage entire leaves conspicuously turn yellow, especially if the infection is severe, and die rapidly, turning brown before dropping from the plants.  Seedbed infections result in marked defoliation without conspicuous yellowing (Jones & Pernezny, 2014; Damicone & Brandenberger, 2015).  In garlic, early symptoms of S. solani infection were observed as white spots (1-3 mm), which enlarged to sunken purple lesions, extending until the leaves withered (Zheng et al., 2008).

Damage Potential:  Gray leaf spot almost entirely affects leaves, and defoliation can be severe reducing available photosynthetic areas of infected plants thereby, resulting in reductions in plant development, quality, and fruit yields.  In China, garlic leaf blight caused by Stemphylium solani affected over 7,000 ha of field production and reduced yields up to 70% (Zheng et al., 2010).  During 1994 and 1995, a severe epidemic of leaf blight of cotton in Brazil resulted in yield losses up to 100% in some commercial fields (Mehta, 1998). Gray leaf spot disease limited tomato production in Venezuela and Malaysia (Cadeño & Carrero, 1997; Nasehi et al., 2012).   In California, processing tomatoes are grown in the warm and dry San Joaquin and Sacramento Valleys while fresh-market tomatoes are grown in the San Joaquin Valley, Central Valley, Central and Southern Coastal regions and the Imperial Valley.  It is less likely that S. solani will be able establish under warm and dry regions of the state’s tomato production acreages, as well as under the possible use of resistant varieties, protectant fungicides and cultural management strategies.  However, for tomato and other host plants under wet and warm climates, the pathogen may be able to establish within those regions.

Worldwide Distribution: Asia: Brunei Darussalam, China, Hong, Kong, Taiwan, Thailand, Korea, Malaysia; Africa: Libya, Mauritius, Senegal, Sudan, Tanzania; Europe: Greece, Spain; North America: Canada, USA (Alabama, Florida, Georgia, Indiana, Louisiana, Maryland, Mississippi, North Carolina, New Jersey, South Carolina, Tennessee, Texas, Virginia); South America: Brazil, Honduras, Venezuela; Central America and Caribbean: Cuba; Oceania: American Samoa (CABI, 2017; Cadeño & Carrero, 1997; Farr & Rossman, 2017).

Official Control: Presently, Stemphylium solani is on the Harmful Organisms list for Peru (USDA-PCIT, 2017).

California Distribution: Stemphylium solani has not been reported from California.

California Interceptions: None reported.

The risk Stemphylium solani would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Although Stemphylium solani has a wide host range that includes several economically important agricultural crops in California as well as wild solanaceous plants, the pathogen is dependent on leaf wetness for plant infection and additionally on warm temperatures for disease development.  The disease is most severe under humid and overcast climate conditions that favor wet foliage mainly due to dew or rain.  These conditions would allow the pathogen to establish in a larger but limited part of California.

Evaluate if the pest would have suitable hosts and climate to establish in California.

Score: 2

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Stemphylium solani has a wide host range of plants included primarily in the family Solanaceae. However, numerous other plant families are also included with their associated hosts.  Economically important crops include tomato, pepper, cotton, citrus, cucumber, lettuce, garlic, eggplant and others.  Several wild solanaceous host plants could allow build-up of fungal inoculum.

Evaluate the host range of the pest.

Score: 3

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

High (3) has a wide host range.

3) Pest Dispersal Potential: Conidia are produced in abundance and readily dispersed by wind and splashing water. Also, the pathogen is spread through infected plants, seedlings, plant debris, and seed.

Evaluate the natural and artificial dispersal potential of the pest.

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Stemphylium solani causes gray leaf spot in tomato and peppers as well as leaf blight in other hosts. Leaves are almost always entirely affected by the disease and defoliation can be severe reducing available photosynthetic areas of plants thereby, resulting in reductions in plant development, quality, and fruit yields.  If not controlled, significant reductions in crop yield and markets could occur.  Use of fungicides and cultural management practices could increase costs of crop production.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, B, C, D

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact:  The pathogen could significantly affect home/urban gardening of agricultural crops and ornamental hosts.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Stemphylium solani: High (13)

Add up the total score and include it here.

-Low = 5-8 points

-Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Evaluation is Not establishedin California.

Score: (0)

Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score:  Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 13

Uncertainty:  

None.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Stemphylium, solani is A.

References:

CABI, 2017.  Stemphylium solani (gray leaf spot) basic datasheet.  Crop Protection Compendium. http://www.cabi.org/cpc/datasheet/51531

Cerkauskas, R.  2005.  Tomato diseases, Gray leaf spot, Stemphylium solani, S. lycopersici found worldwide in warm climates.  AVRDC – The World Vegetable Center Fact Sheet.  AVRDC Publication 05-634.

Cadeño, L., and C. Carrero.  1997.  First report of tomato gray leaf spot caused by Stemphylium solani in the Andes Region of Venezuela.  Plant Disease 81: 1332. http://dx.doi.org/10.1094/PDIS.1997.81.11.1332B

Damicone, J. P., and L. Brandenberger.  2015.  Common diseases of tomatoes Part 1.  Diseases caused by fungi.  Oklahoma Cooperative Extension Service EPP-7625.

Farr, D. F., and A. Y. Rossman.  2017.  Fungal Databases, U. S. National Fungus Collections, ARS, USDA. Retrieved April 3, 2017, from http://nt.ars-grin.gov/fungaldatabases/

Jones, J. P., and K. L. Pernezny.  2014.  Gray Leaf Spot.  In Compendium of Tomato Disease and Pests Second Edition.  Ed. J. B. Jones, T. A. Zitter, T. M. Momol, and S. A. Miller, APS Press. The American Phytopathological Society.  29-30 p.

Koike, S. T., P. Gladders, and A. O. Paulus.  2007.  Stemphylium solani, S. lycopersici – gray leaf spot.  In Vegetables diseases a color handbook.  Academic Press, an imprint of Elsevier, Burlington, San Diego.  211-212 p.

Mehta, Y. R.  1998.  Severe outbreak of Stemphylium leaf blight, a new disease of cotton in Brazil. Plant Disease, 82: 333-336.

Nasehi, A., J. B. Kadir, M. A. Zainal Abidin, M. Y. Wong, and F. Mahmodi.  First report of tomato gray leaf spot disease caused by Stemphylium solani in Malaysia.  Plant Disease 96: 1226.  http://dx.doi.org/10.1094/PDIS-03-12-0223-PDN

USDA PCIT.  2017.  USDA Phytosanitary Certificate Issuance & Tracking System. April 3, 2017, 1:17:10 pm CDT.  https://pcit.aphis.usda.gov/PExD/faces/ReportHarmOrgs.jsp.

Zheng, L., J. B. HUANG, and T. HSIANG.  2008.  First report of leaf blight of garlic (Allium sativum) caused by Stemphylium solani in China. Plant Pathology 57: 380.

Zheng, L., L. V. Rujing, J. Huang, D. Jiang, X. Liu, and T. Hsiang.  2010.  Integrated control of garlic leaf blight caused by Stemphylium solani in China.  Canadian Journal of Plant Pathology 32: 135-145.


Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.


Comment Period: CLOSED

Apr 20, 2017 – June 4, 2017


Comment Format:

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Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

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Pest Rating: A


Posted by ls