Category Archives: C-Rated

“C”
A pest of known economic or environmental detriment and, if present in California, it is usually widespread. C-rated organisms are eligible to enter the state as long as the commodities with which they are associated conform to pest cleanliness standards when found in nursery stock shipments. If found in the state, they are subject to regulations designed to retard spread or to suppress at the discretion of the individual county agricultural commissioner. There is no state enforced action other than providing for pest cleanliness.

C-Rated, Coleoptera, Insects, Mites & Earthworms

Weevil | Oxydema longula (Boheman)

California Pest Rating  for
Weevil | Oxydema longula (Boheman)
Coleoptera: Curculionidae
Pest Rating: C

 

PEST RATING PROFILE

Initiating Event:

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

History & Status:

Background:  Oxydema longula is a weevil that measure 5-5.5 mm in length and is black and shining (Boheman, 1859).  The species occurs in a variety of dead and decaying plant material, and the larvae are reported to feed in dead ferns and bamboo and rotting wood (Blackburn and Sharp, 1887; Swezey, 1922; Swezey, 1925; Swezey, 1954).  This weevil has been reported to be associated with living plants as well.  For example, it bored into rubber trees and “matured” sisal plants and “riddled” a papaya tree in Hawaii (Kuhns, 1908; Smith and Bradford, 1908; Van Dine, 1906).  The species has also been intercepted on cordyline (Hunt, 1954).  These records do not necessarily indicate that this weevil attacks living plant tissue.  The boring in rubber trees occurred in rubber tapping injuries.  Regarding the sisal plant records, this plant is harvested via removal of older leaves, so the burrowing of the weevil could have exploited dead tissue resulting from harvesting injuries.  The weevil(s) intercepted on cordyline could simply have been using the plant as shelter, or it could have been feeding on a dead portion of the plant.

Little information was found on the biology of the genus Oxydema, but Oxydema fusiforme Wollaston is reported to feed on rotting plant material, including rotting wood and boards and dead morning glory vines (Hawaiian Entomological Society, 1922; Hawaiian Entomological Society, 1935; Loschiavo and Okumura, 1979).

Synonyms of Oxydema longula include Oxydema longulum (Boheman), Oxydema longulus (Boheman), Pseudolus longulus (Boheman), and Rhyncolus longulus Boheman.  Information reported for these synonyms was considered in this proposal.

Worldwide Distribution:  Oxydema longula is reported from Hawaii (all islands), Midway Atoll, and Saipan Island (Konishi, 1956; Suehiro, 1960; Zimmerman, 1940).  It may be native to Hawaii and introduced to the other areas.

Official Control: Oxydema longula is not known to be under official control anywhere.

California Distribution:  Oxydema longula is not known to be present in California.

California Interceptions:  Oxydema longula has been intercepted 12 times on various plant products from Hawaii, including cut flowers (CDFA Pest and Damage Report Database, 2018).

The risk Oxydema longula would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Oxydema longula is found in areas with a tropical to subtropical climate. Climate may limit this weevil’s potential distribution in California.  This weevil apparently feeds on a wide variety of decaying plant material.  Presence of food is not expected to be a limiting factor in its potential distribution in California. Therefore, Oxydema longula receives a Medium (2) in this category.

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: Oxydema longula is reported to feed on a wide variety of rotting plant material. Therefore, it receives a High (3) in this category.

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: Another species of Oxydema, fusiforme, was collected at light in Hawaii, so it presumably flies (Browne, 1942).  Oxydema longula is presumed to fly as well.  Therefore, it receives a Medium (2) in this category.

Score: 2

– 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: Oxydema longula has not been reported to cause economic damage.  The available evidence strongly suggests that it feeds on dead, rotting plant material.  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: Oxydema longula apparently feeds on dead plant material. The species is therefore not expected to threaten living plants.  However, it could compete with native insects that also feed on dead plant material.  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.

Score the pest for Environmental Impact. Score:

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 Oxydema longula: Medium (10)

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: Oxydema longula 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: Medium (10)

Uncertainty:

There is a possibility that O. longula may feed on living plant tissue, although the available reports generally state dead (often rotting) plant material as the food.

Conclusion and Rating Justification:

Oxydema longula is a weevil that is reported to feed on dead plant material.  This saprophagous lifestyle suggests that it does not pose an economic or environmental risk to California.  For these reasons, a “C” rating is justified.

References:

Blackburn, T. and Sharp, D.  1885.  Memoirs on the Coleoptera of the Hawaiian Islands.  The Scientific Transactions of the Royal Dublin Society 3:119-300.

Boheman, C. H.  1859.  Coleoptera.  pp. 113-218 in Kongliga Svenska Fregatten Eugenies.  P.A. Norstedt & Söner, Stockholm.

Browne, A. C.  1942.  Insects taken at light at Kalawahine Place, Honolulu.  Proceedings of the Hawaiian Entomological Society 11:151-152.

CDFA Pest and Damage Report Database.  2018.  Oxydema longula.  Plant Health and Pest Prevention Services. CA Department of Food and Agriculture.  Accessed April 16, 2018: https://pdr.cdfa.ca.gov/PDR/pdrmainmenu.aspx

Hawaiian Entomological Society.  1922.  November 3, 1921.  Proceedings of the Hawaiian Entomological Society 5:32-35.

Hawaiian Entomological Society.  1935.  April 5, 1934.  Proceedings of the Hawaiian Entomological Society 5:12-16.

Hunt, J.  1954.  List of intercepted plant pests, 1954.  United States Department of Agriculture.

Konishi, M.  1955.  Cossoninae of Marcus Island.  Insecta Matsumurana 19:64.

Kuhns, D. B.  Noted on Maui insects.  Proceedings of the Hawaiian Entomological Society 2:93.

Loschiavo, S. R. and Okumura, G. T.  1979.  A survey of stored product insects in Hawaii.  Proceedings of the Hawaiian Entomological Society 13:95-118.

Smith, J. G. and Bradford, Q. Q.  1908.  The ceara rubber tree in Hawaii.  Bulletin of the Hawaii Agricultural Station 16:1-30.

Suehiro, A.  1960.  Insects and other arthropods from Midway Atoll.  Proceedings of the Hawaiian Entomological Society 17:289-298.

Swezey, O. H.  1922.  Insects attacking ferns in the Hawaiian Islands.  Proceedings of the Hawaiian Entomological Society 5:57-65.

Swezey, O. H.  1925.  The insect fauna of trees and plants as an index of their endemicity and relative antiquity in the Hawaiian Islands.  Proceedings of the Hawaiian Entomological Society 6:195-209.

Swezey, O. H.  1954.  Forest entomology in Hawaii.  Bernice Bishop Museum Special Publication 44:1-265.

Symbiota Collections of Arthropods Network.  Accessed April 27, 2018. http://scan1.acis.ufl.edu

Van Dine, D. L.  1906.  Report of the entomologist.  Report on Agricultural Investigations in Hawaii 1906:38-59.

Zimmerman, E. C.  1940.  Synopsis of the genera of Hawaiian Cossoninae with notes on their origin and distribution.  Occasional Papers of Bernice P. Bishop Museum, Honolulu, Hawaii 15:271-293.

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

7/3/18 – 8/17/18

*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 

C-Rated, Coleoptera, Insects, Mites & Earthworms

Weevil | Dryophthorus homoeorhynchus Perkins

California Pest Rating for 
Dryophthorus homoeorhynchus Perkins: weevil
Coleoptera: Dryopthoridae
Pest Rating: C

 

PEST RATING PROFILE
Initiating Event:

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

History & Status:

Background:  This beetle is black in color, elongate, and 4.5-6 mm in length.  The species has a short rostrum (“beak”) (Perkins, 1900).  Larvae of all species of Dryophthorus, including D. homoeorhynchus, apparently feed on rotting plant material, primarily wood.  Dryophthorus homoeorhynchus is reported to feed on decomposing Chrysodracon species (Dracaenaceae) in Hawaii (Swezey, 1931; Swezey, 1954; Wagner et al., 2005).  Other species in the genus are reported to feed on rotting hardwood and conifer wood, and at least one species has been reported to feed on rotting tree fern fronds (Hawaiian Entomological Society, 1928; O’Brien, 1997).

Worldwide Distribution:  This beetle is native to, and is only known to occur in Hawaii.  The species has been reported from Hawaii, Oahu, Maui, and Molokai islands (Natural Resources Conservation Service, 2009; Swezey, 1954).

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

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

California Interceptions:  This beetle was intercepted on pineapple from Hawaii in February 2004 (California Department of Food and Agriculture).

The risk Dryophthorus homoeorhynchus would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Dryophthorus homoeorhynchus is only known to occur in Hawaii. If this beetle requires the climate found in its current area of distribution, then only a small portion of California would offer a similar suitable climate.   At least one species in the family Dracaenaceae, Dracaena draco, is grown as an outdoor plant in California and could possibly serve as a host plant for homoeorhynchus.  Due to the apparent climate restrictions, it appears unlikely that this beetle could become established in more than a small portion of California.  Therefore, D. homoeorhynchus 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: Dryophthorus homoeorhynchus is only known to feed on the genus Chrysodracon. Therefore, it receives a Low (1) 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: The biology of homoeorhynchus is poorly known.  The beetle is assumed to fly.  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: This beetle is only known to feed on dead plant material, as are all other members of the genus.  Negative economic impacts are unlikely if this beetle became established in California.  The species apparently feeds on decomposing plant material, not freshly-cut wood, and is known to be restricted to plants in the family Dracaenaceae, therefore there is little risk to timber. 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: Negative environmental impacts of this species if it became established in California appear minimal. The species feeds on dead plant material, and it appears to be restricted to a family of plants, the Dracaenaceae, that do not include any native California species.  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.

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 Dryophthorus homoeorhynchus: Low (6)

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: Dryophthorus homoeorhynchus 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: Low (6)

Uncertainty:

Dryophthorus homoeorhynchus may be able to tolerate cooler temperatures than are present in its native distribution.  If this is the case, the species could become established over a greater portion of California if suitable plant material is present.  The beetle may also be able to feed on plants in families other than Dracaenaceae.  Feeding on living plant tissue, however, has not been reported in Hawaii and apparently all species in the genus Dryophthorus feed on dead, rotting plant tissue.

Conclusion and Rating Justification:

Dryophthorus homoeorhynchus is a tropical/subtropical beetle that feeds on dead plants in the family Dracaenaceae, and it is a member of a genus that is apparently restricted to dead, rotting plant material.  This beetle appears to pose no threat, economic or environmental, to California.  For these reasons, a “C” rating is justified.

References:

California Department of Food and Agriculture.  Pest and damage record database.  Accessed March 22, 2018. https://pdr.cdfa.ca.gov/PDR/pdrmainmenu.aspx

Hawaiian Entomological Society.  1928.  January 6, 1927; notes and exhibitions.  Proceedings of the Hawaiian Entomological Society.  7: 1-31.

Natural Resources Conservation Service.  2009.  At-risk species and habitats lists.  Biology Technical Note.  22: 1-403.

O’Brien, C.W.  1997.  A catalog of the Coleoptera of America north of Mexico.  Family: Curculionidae.  Subfamilies: Acicnemidinae, Cossoninae, Rhytirrhininae, Molytinae, Petalochilinae, Trypetidinae, Dryophthorinae, Tachygoninae, Thecesterninae.  United States Department of Agriculture.  48 pp.

Perkins, R.C.L.  1900.  II.  Coleoptera Rhyncophora, Proterhinidae, Heteromera and Cioidae.  117-270 in   (D. Sharp, ed.) Fauna Hawaiiensis.  Cambridge University Press.  London.  579 pp.

Swezey, O.H.  1931.  Some new records of insects on Molokai.  Proceedings of the Hawaiian Entomological Society.  7: 485-488.

Swezey, O.H.  1954.  Forest entomology in Hawaii.  Bernice P. Bishop Museum Special Publication.  44: 1-265.

Symbiota Collections of Arthropods Network.  Accessed March 20, 2018. http://scan1.acis.ufl.edu

Wagner, W.L., Herbst, D.R., and Lorence, D.H.  2005.  Flora of the Hawaiian Islands.  Accessed March 20, 2018. http://botany.si.edu/pacificislandbiodiversity/hawaiianflora/index.htm

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

4/30/18 – 6/14/18

*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 

C-Rated, Hemiptera, Insects, Mites & Earthworms

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

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Pest Rating: C

Posted by ls 

C-Rated, Fungi, Plant Pathogens

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: 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.

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.

*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