Tag Archives: Coleoptera

Coleoptera, Insects, Mites & Earthworms

South American Palm Weevil |  Rhynchophorus palmarum (Linnaeus)

California Pest Rating for

South American palm weevil (Dynamis borassi) Champion, G.C. , 1910

South American Palm Weevil |  Rhynchophorus palmarum (Linnaeus)
Coleoptera: Curculionidae
Pest Rating:  B

 

PEST RATING PROFILE

Initiating Event:

On March 17, 2016 several adult and larval weevils collected by San Diego County officials during the removal of a Canary Island date palm in San Ysidro were identified as Rhynchophorus palmarum, South American palm weevil (SAPW) (PDR 370P06400129).  Although SAPW has been found in this area since 2011 this is the first confirmation of a breeding population in California.  A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background:  Adult female SAPW are attracted to fresh trunk wounds of palm trees and lay their eggs inside a hole in the trunk that they have chewed1.  After hatching, larvae bore into the tree where they feed on live and rotting tissue1.  This feeding can eventually lead to death of the palm.  SAPW adult females are known to vector the nematode Bursaphelenchus cocophilus (red ring nematode), which accelerates the death of the host palm1.  Known reproductive hosts include: Arecaceae: Cocos nucifera (coconut), Elaeis guineensis (Afrian oil palm), Euterpe edulis (assai palm), Metroxylon sagu (sago palm), Phoenix canariensis (Canary Island date palm), Phoenix dactylifera (date palm); Poaceae: Saccharum officinarum (sugarcane)1.  Adult weevils also feed on a wide variety of fruits and other plants but have never been documented to be a pest of these hosts.  SAPW may be transported long distances when infested palm trees or palm parts are moved.

Worldwide Distribution: SAPW is native to Central and South America, and has spread northward throughout Mexico, presumably due to unrestricted movement of palm nursery stock.   The beetle is now making incursions across the southern border of the United States into California, Arizona, and Texas.

Official Control: SAPW is listed as a harmful organism by Albania, Austria, Belgium, Bulgaria, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Holy See (Vatican City State), Honduras, Hungary, Indonesia, Ireland, Italy, Jamaica, Japan, Korea, Latvia, Lithuania, Luxembourg, Malta, Monaco, Montenegro, Morocco, Namibia, Netherlands, Poland, Portugal, Romania, San Marino, Serbia, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Taiwan, Timor-Leste, and the United Kingdom2.  Bursaphelenchus cocophilus, a nematode that is vectored by SAPW, is listed as a harmful organism by Antigua and Barbuda, Chile, China, Colombia, Dominica, Honduras, Jamaica, and Saint Lucia2.

California Distribution:  SAPW has been found in southern San Diego and Imperial counties since 2011, and may have been flying into these areas from Mexico since 19661.

California Interceptions:  SAPW has not been found in any regulatory situations in California.

The risk Rhynchophorus palmarum (SAPW) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: SAPW can be expected to establish throughout California wherever suitable hosts are grown. The weevil is protected from the environment inside palms and is unlikely to be extirpated by cold weather.  SAPW receives a High (3) in this category.

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) Known Pest Host Range: SAPW is known to reproduce in seven species of plants in two plant families.  Adult weevils also feed on a wide variety of food sources, including many fruits and other plants.  However, it has only been documented to be a pest of palms and sugarcane.  It receives a High (3) in this category.

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: SAPW has high reproductive rates.  Each female can lay 120-150 eggs over a period of 30 days and the weevils can complete a generation in 80 days1.  SAPW can fly a mile in 24 hours and may be transported long distances when infested palms or sugarcane are moved1.  SAPW receives a High (3) 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: As it expands its range in California, SAPW is likely to reduce yields in date groves and palm nurseries by destroying trees.  The species might also increase crop production costs in date groves and lower the value of palm nursery stock.  SAPW is considered a quarantine pest by many of California’s trading partners and has the potential to disrupt exports as a contaminating pest.  SAPW is also known to vector the plant pathogenic nematode Bursaphelenchus cocophilus.  SAPW receives a High (3) in this category.

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

A, B, C, E

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: As it expands its range in California, SAPW is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.   The beetle is not likely to directly affect any threatened or endangered species or disrupt any critical habitats.  SAPW may trigger new treatments by residents, by the nursery industry, and by date growers.  Palm trees are an iconic ornamental plant in the California landscape and may be significantly impacted by this pest.  SAPW receives a High (3) in this category.

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

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.

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 Common Name:  High (15)

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: SAPW is only known to have established a localized distribution in southern San Diego County and to have made incursions into Imperial County. The species receives a Low (-1) 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: High (14)

Uncertainty:

CDFA’s palm weevil trapping was mostly discontinued in 2013, and it is possible that Rhynchophorus palmarum has expanded its range in California since that time.  The species may have additional host trees or switch hosts multiple times in California.  The weevil could switch hosts and feed on native palms, which would disrupt natural communities.  However, the weevils have significant populations in areas with many native Washingtonia palms and have not affected those trees.  Unfortunately, there is one report of SAPW feeding on Washingtonia robusta in Mexico4.

Conclusion and Rating Justification:

SAPW is likely to have significant economic and environmental impacts as it expands its range in California.  However, it is already found in southern San Diego and Imperial counties and is thought to regularly enter the state from Mexico.  The weevil is not under official control (e.g., quarantine or eradication).  There are no plans for federal agencies to take any action on this pest3.  A “B”-rating is appropriate.

References:

1 Rhynchophorus palmarum.  USDA APHIS 2011.  https://www.aphis.usda.gov/plant_health/plant_pest_info/palmweevil/downloads/Rhynchophoruspalmarum_v5.pdf

2 USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD).  https://pcit.aphis.usda.gov/pcit/

3 Summary of Recommendations for Palm Weevils. 2013.  The PPQ Palm Weevil Working Group (PWWG).

4 García-Hernández, José Luis, Luis Felipe Beltrán-Morales, José Guadalupe Loya-Ramírez, J.R. Morales-Cota, Enrique Troyo Diéguez, and Félix Alfredo Beltrán-Morales.  2003.  Primer informe del Rhynchophorus palmarum (Coleoptera: Dryophthoridae) en Baja California Sur. Folia Entomol. Mex. 42(3): 415-417.

Responsible Party:

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

Comment Period:* CLOSED

1/24/18 – 3/10/18

*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

Coleoptera, Insects, Mites & Earthworms

Black Pine Bark Beetle | Hylastes ater (Paykull)

California Pest Rating for
Black Pine Bark Beetle | Hylastes ater (Paykull)
Pest Rating: A

 

PEST RATING PROFILE

Initiating Event:

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

History & Status:

Background: Hylastes ater is fairly large (3.5-4.4 mm long) sized for a bark beetle.  The beetle is dark in color, almost black.  Hylastes ater larval feeding appears to be limited to the roots and stumps of already-cut conifers (mostly pine, Pinus spp.).  Adults burrow into the phloem (inner bark), forming tunnels in which the larvae feed.  Feeding by newly-emerged adult bark beetles takes place in seedlings.  As is commonly the case with bark beetles, multiple species of fungi are associated with H. ater.  Sapstain fungi may be transferred to recently-cut logs by adult H. ater through their feeding.  This fungus can decrease the value of wood.

Worldwide Distribution: Hylastes ater is native to a large portion of the Palearctic, including much of Europe.  The species has been introduced to Australia, Chile, New Zealand, and South Africa.

Official Control: This species is considered a quarantine pest by Canada.

California Distribution:  This species is not known to be present in California.

California Interceptions: Hylastes ater has been intercepted in California on Pinus radiata wood from New Zealand (PDR # 1166010 and 1059432).

The risk Hylastes ater would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Hylastes ater is widely distributed in the Palearctic, and has demonstrated its ability to be introduced successfully to various localities, including Australia, Chile, and New Zealand. This species feeds on pines, which occur throughout California.  Therefore, Hylastes ater 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: Hylastes ater has been reported to feed on many species of pines as well as other coniferous trees. Therefore, it 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: Hylastes ater flies, and has successfully been introduced to several countries. Adults are strongly attracted to freshly-cut logs, which means these beetles are likely to be present on logs/firewood that are not removed immediately after cutting.  This would enable the beetles to be moved with the logs/firewood.  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: Hylastes ater has been reported to cause heavy mortality of pine seedlings in New Zealand, primarily as a result of the feeding of newly emerged adults described above.  There is some evidence that healthy seedlings are generally not damaged or killed as a result of this feeding, and that it is only otherwise-compromised seedlings that are affected.  Assuming that healthy seedlings are damaged or killed, the introduction of ater to California could impact the timber industry through increasing production costs, both through loss of seedlings as well as infection of logs by sapstain fungi.  Timing of cutting or harvesting of timber could require modification, to avoid the beetles.  Therefore, it receives a High (3) in this category.

Economic Impact:  B, D, E

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: There does not appear to be any evidence that Hylastes ater has a significant environmental impact in any of the areas to which it has been introduced. Any significant damage to pine seedlings in timber operations may be related to the artificially higher density of food sources (wood waste) and resulting high densities of adult beetles.  However, it is possible that this species could have a different impact in California if it was introduced here.  There is also a possibility that the species could carry a fungal pathogen to which California trees are susceptible.  Forest ecosystems and rare California conifers could be affected.  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.

Score the pest for Environmental Impact. Score:

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 Hylastes ater: 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: Hylastes ater 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:

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

Uncertainty:

Besides any damage to already-cut timber by the transmitted fungi, the only evidence so far of damage resulting from this beetle is the feeding by newly emerged adults on tree seedlings.  There appears to be some uncertainty regarding the ability of the adults to injure or kill healthy pine seedlings; some research suggests that injured/killed seedlings were originally in poor health prior to being fed upon.

Conclusion and Rating Justification:

Hylastes ater is a bark beetle that is not known to occur in the United States and has the potential to impact the timber industry through direct feeding damage of seedlings or transmission of pathogenic fungi.  There could be environmental impacts as well.  In addition, there are pine species in California (some of them rare) that this bark beetle has not encountered before, and the behavior (including damage) of the beetle could be different from what has been observed to date in other parts of the world.  An “A” rating is justified.

References:

Bain, J., Berndt, L., and B. Gresham.  2009.  Forest and timber insects in New Zealand.  Number 29: Black pine bark beetle. http://www.nzffa.org.nz/farm-forestry-model/the-essentials/forest-health-pests-and-diseases/Pests/Hylastes-ater/Hylastes-aterEnt29

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

EPPO.  2017.  EPPO Global Database (available online).  Accessed 21 September 2017. https://gd.eppo.int

Kliejunas, J.T, Burdsall Jr., H.H., DeNitto, G.A., Eglitis, A., Haugen, D.A., Haverty, M.I., and J.A. Micales.  2006.  Pest risk assessment of the importation into the United States of unprocessed Pinus logs and chips from Australia.  United States Department of Agriculture.  159 pp.

Reay, S.D., Glare, T.R., and M. Brownbridge.  2012.  Hylastes ater (Curculionidae: Scolytinae) affecting Pinus radiata seedling establishment in New Zealand.  Psyche.  2012: 1-9.

Wood, S.L.  1982.  The bark and ambrosia beetles of North and Central America (Coleoptera: Scolytidae), a taxonomic monograph.  Brigham Young University.  1359 pp.

Wood, S.L.  2007.  Bark and ambrosia beetles of South America.  Brigham Young University.  900 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 Drive, Sacramento CA 95833, (916) 654-1211;  plant.health[@]cdfa.ca.gov.

Comment Period:* CLOSED

1/17/2018 – 3/3/2018

*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

Coleoptera, Insects, Mites & Earthworms

Bark Beetle | Coccotrypes rutschuruensis Eggers

California Pest Rating for
Bark Beetle | Coccotrypes rutschuruensis Eggers
Pest Rating: A

 

PEST RATING PROFILE

 

Initiating Event:

In 1987, beetles were found mining the bases of seedlings of the palm, Howea forsteriana, in Orange County (PDR # 821414).  The beetles were identified as Coccotrypes rutschuruensis (misspelled in the PDR as rutshuruensis).  This apparently represents the only detection of the species in the United States.

History & Status:

Background: This species has been found associated with the following plants: Annona sp. (Annonaceae), Astrocaryum murumura, Howea forsteriana, Phoenix reclinata (Arecaceae), and Triplochiton scleroxylon (Malvaceae).  Wood (2007) considered it possible that what he treated as C. rutschuruensis could have been two or more species.  Therefore, the biological data of multiple species may have been combined and the specific identification of members of this genus may be problematic.  Regardless, little biological information is available for the beetles that have been referred to by this name except for reports of feeding on the bases of seedlings of Howea forsteriana and in Astrocaryum palm nuts.  For both of these reasons (doubtful species identity and poorly-known biology), a cautious approach must be taken and the biology of the entire genus Coccotrypes will be drawn upon in this proposal.

Worldwide Distribution: Coccotrypes rutschuruensis was described from material collected in Rutshuru, Democratic Republic of the Congo, and it is presumably native to that continent.  The 1987 Orange County find is apparently the only record of this species in the United States, and it is presumed that this species is not established in this country (Haack and Rabaglia 2013).  There are reports that this species has been introduced to Brazil and Suriname (Wood, 2007).  Unfortunately, these records may represent one or more different species due to the confused taxonomy.

Official Control: Coccotrypes rutschuruensis is not known to be under official control anywhere.

California Distribution: This species is not known to occur in the United States.

California Interceptions: The above-mentioned detection in Orange County is apparently the only record of this species in California (and the United States).

The risk Coccotrypes rutschuruensis would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: The available distribution records suggest that the species is primarily tropical but may also be capable of establishment in temperate climates, although this depends on the specimens identified as rutschuruensis in South America actually being that species. Because of the lack of biological information available on this species and the doubt regarding the species identities, the broad, collective climatic tolerance of the entire genus Coccotrypes is considered.  Regarding host plants, this beetles appears to be mostly restricted to palms.  There is only one native palm in California, but many species are planted as ornamentals in the southern half of the state.  Therefore, C. rutschuruensis receives a Medium (2) 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: The available feeding records for Coccotrypes rutschuruensis all involve palms, although there is little biological information available. The feeding habits of the entire genus Coccotrypes are considered.  Therefore, Coccotrypes rutschuruensis 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: Coccotrypes species are inbreeding and can reproduce via arrhenotokous parthenogenesis. This means that a single, unfertilized female is capable of founding a population by producing males from unfertilized eggs and mating with them.  In addition, Coccotrypes species are known to fly.  Therefore, Coccotrypes rutschuruensis receives a High (3) 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: The beetles identified as rutschuruensis were reported feeding on palm seeds and seedlings. It is possible that if it were to become established in California, this beetle could impact the date and ornamental palm industries, including lowering yield and disrupting markets and increasing production costs.  Therefore, it receives a High (3) in this category.

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: Coccotrypes rutschuruensis is reported to feed on palm seeds and seedlings. Another species of Coccotrypes, carpophagus, has been reported to feed on Washingtonia filifera and W. robusta.  If introduced into California, C. rutschuruensis could impact the regeneration of the native Washingtonia filifera palm in southern California.  This beetle could also impact ornamental palm plantings and trigger treatment programs if planted palms were attacked.  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, 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.

Score the pest for Environmental Impact. Score:

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 Coccotrypes rutschuruensis: High (14)

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: Coccotrypes rutschuruensis been found only once in California (the Orange County find cited above).  Because there is no further evidence of this species in the state, 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: High (14)

Uncertainty:

Coccotrypes is diverse (129 described species) and the body size is minute.  This makes identification challenging even in a best-case scenario (i.e., if the systematics of the group have been well-studied, or a modern revision existed).  In many cases, specimens of Coccotrypes are only identified to the level of genus.  This means that, even if C. rutschuruensis was established in the United States, it may not have been identified as that species.  In addition, the sparseness of biological data available for this species, along with the doubt regarding its identity, leads the author to consider the biology of the entire genus Coccotrypes in developing a rating.

Conclusion and Rating Justification:

The beetles historically identified as C. rutschuruensis have been reported feeding on palm seeds and seedlings.  This raises the possibility of economic and environmental damage if this species became established.  There is apparently a possibility that other Coccotrypes species may be referred to as C. rutschuruensis, which means that a specimen intercepted in California and identified as C. rutschuruensis may be a different species with a different biology (including feeding habits and climatic tolerances).  For this reason, a cautious approach has been taken.  Coccotrypes rutschuruensis deserves an “A” rating.

References:

Atkinson, T.H.  2017.  Bark and ambrosia beetles of North and Central America. http://www.barkbeetles.info

Haack, R.A.  2001.  Intercepted Scolytidae (Coleoptera) at U.S. ports of entry: 1985-2000.  Integrated Pest Management.  6: 253-282.

Haack, R.A. and R.J. Rabaglia.  2013.  Exotic bark and ambrosia beetles in the USA: Potential and current invaders.  In (J. Peña, ed.): Potential pests of agricultural crops (pp. 48-74).  CAB International.

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

Wood, S.L.  2007.  Bark and ambrosia beetles of South America.  Brigham Young University.  900 pp.

Wood, S.L. and D.E. Bright.  1992.  A catalog of Scolytidae and Platypodidae (Coleoptera), Part 2: Taxonomic index.  Great Basin Naturalist Memoirs.  13: 1-1553.

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 Drive, Sacramento CA 95833, (916) 654-1211;  plant.health[@]cdfa.ca.gov.

Comment Period:* CLOSED

1/16/2018 – 3/2/2018

*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

Coleoptera, Insects, Mites & Earthworms

A Bark Beetle | Pycnarthrum hispidum (Ferrari)

California Pest Rating for
A Bark Beetle | Pycnarthrum hispidum (Ferrari)
Coleoptera
Pest Rating: C

 

PEST RATING PROFILE

Initiating Event:

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

History & Status:

Background:  Pycnarthrum hispidum is a neotropical bark beetle that occurs at low elevations below 1300 meters above sea level.  The feeding behavior is apparently restricted to the phloem of cut, injured, or fallen limbs and trunks of fig trees (Ficus spp.).  No reports were found suggesting that it attacks living, healthy trees.  The species has been associated with the following Ficus species: F. lyrata, F. elastica, and F. retusa.

Worldwide Distribution:  Pycnarthrum hispidum occurs in the United States (south Texas and south Florida), Mexico, the Caribbean, Central America, Venezuela, and Guyana.

Official Control: Pycnarthrum hispidum does not appear to be under official control anywhere.

California Distribution:  Pycnarthrum hispidum is not known to occur in California.

California Interceptions: Pycnarthrum hispidum was intercepted on Artemisia sp., Ficus sp., and Ceratonia silique from Florida (PDR # 010P06660363, 010P06660369, 010P06660366, and 010P06660375).

The risk Pycnarthrum hispidum would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Pycnarthrum hispidum occurs in tropical/subtropical areas. There is a possibility that it could become established in a limited portion of California.  Ficus species are grown as ornamental trees in California and could serve as host plants.  Therefore, Pycnarthrum hispidum receives a Medium (2) 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: Pycnarthrum hispidum is apparently restricted to the genus Ficus. 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: Pycnarthrum hispidum is capable of sustained flight, and is attracted to light.  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: The available information suggests that Pycnarthrum hispidum does not impact living trees.  The two most obvious concerns regarding the possible establishment of a species that feeds on Ficus are ornamental trees and commercial fig fruit, but these concerns are not supported by evidence.  In 2016, figs were grown in 32 Mexican states and the harvest was worth approximately 514 million pesos.  Yet, there do not appear to be any reports of P. hispidum as a pest of figs there, or anywhere else.  Ficus species are also widely planted as ornamental trees, and again, no reports were found of P. hispidum as a pest.  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: Pycnarthrum hispidum is only known to feed on Ficus species, and there are no species in this genus (or even the family Moraceae) native to California. Additionally, as explained above in Economic Impact, there does not appear to be significant potential for hispidum to become an economic pest.  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 Pycnarthrum hispidum: Low (7)

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: Pycnarthrum hispidum 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 (7)

Uncertainty:

There appears to be little uncertainty regarding the possible impact of Pycnarthrum hispidum in California.  The species is widely distributed and common and not a single report was found of it attacking live trees.

Conclusion and Rating Justification:

Pycnarthrum hispidum is a common, Neotropical insect that apparently feeds on cut branches and trunks of Ficus spp.  No reports were found suggesting it is a pest in any situation.  It does not appear to pose a threat to California’s agriculture or environment.  For these reasons, a “C” rating is justified.

References:

Atkinson, T.H. and A.E. Martínez.  1985.  Notes on biology and distribution of Mexican and Central American Scolytidae (Coleoptera).  I.  Hylesininae, Scolytinae except Cryphalini and Corthylini.  The Coleopterists Bulletin.  39(3): 227-238.

Atkinson, T.H., Martínez-Fernández, E., Saucedo-Céspedes, E., and A. Burgos-Solorio.  1986.  Scolytidae y Platypodidae (Coleoptera) asociados a selva baja y comunidades derivadas en el estado de Morelos.  Folia Entomolόgica Mexicana.  69: 41-82.

Martínez, A.E. and T.H. Atkinson.  1986.  Annotated checklist of bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) associated with a tropical deciduous forest at Chamela, Jalisco, Mexico.  Florida Entomologist.  69(4): 619-635.

Servicio de Informaciόn Agroalimentaria y Pesquera.  Anuario Estadístico de la Producciόn Agrícola.  http://nube.siap.gob.mx/cierre_agricola/

Symbiota Collections of Arthropods Network (SCAN).  http://symbiota4.acis.ufl.edu

Valencia, A.E. and T.H. Atkinson.  1988.  Scolytidae y Platypodidae (Coleoptera) de escárcega, Campeche, México.  Biogeografia, biología, importancia econόmica y una lista comentada de especies.  Anales del Instituto de Biología, Universidad Nacional Autόnoma de México.  58: 199-220.

Wood, S.L.  1982.  The bark and ambrosia beetles of North and Central America (Coleoptera: Scolytidae), a taxonomic monograph.  Brigham Young University.  1359 pp.

Wood, S.L.  2007.  Bark and ambrosia beetles of South America.  Brigham Young University.  900 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 Drive, Sacramento CA 95833, (916) 654-1211;  plant.health[@]cdfa.ca.gov.

Comment Period:* CLOSED

1/16/2018 – 3/2/2018

*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

Coleoptera, Insects, Mites & Earthworms

Banded Elm Bark Beetle | Scolytus schevyrewi Semenov

California Pest Rating  for
Banded Elm Bark Beetle | Scolytus schevyrewi Semenov
Coleoptera
Pest Rating: C

 

PEST RATING PROFILE

Initiating Event:

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

History & Status:

Background: Scolytus schevyrewi can be recognized by its relatively large size (2.7-4.3 mm in length), the dark band running across the median portions of the elytra, and the position and shape of the abdominal spine.  In the United States, this species attacks elms (Ulmus americana, U. pumila, U. thomasii, and U. procera).  In its native range, it has been reported feeding on trees in the genera Malus and Prunus.  These genera include important fruit trees in California.  As of 2005, however, there were no records of this beetle attacking trees other than elms in the United States.  The species appears to preferentially attack, or cause greater damage to weakened or stressed trees.  Drought stress may be associated with greater damage.  Maturation feeding (feeding by adults before mating) occurs on twigs.  This beetle is apparently capable of transmitting the Dutch elm disease fungus to otherwise healthy trees, and maturation feeding is one way this could occur.

Worldwide Distribution: Scolytus schevyrewi is native to northern China, Central Asia, and Russia.  The beetle was introduced to the United States in 1994 or earlier, as this when the first specimen was collected, but recognition of the species and the fact it was present in the United States took a decade, probably because of the similarity of this species to Scolytus multistriatus.  Scolytus schevyrewi is widely distributed in the United States and has been reported from at least 28 states.  The species has also been introduced to Canada and Mexico.

Official Control: Scolytus schevyrewi is not known to be under official control anywhere.

California Distribution:  Scolytus schevyrewi has been found in at least 13 counties in California, ranging from Lassen County in the north to San Diego County in the south.

California Interceptions: Scolytus schevyrewi has been trapped in 9 counties from 2004-2010 (Kern, Inyo, Lassen, Los Angeles, Mono, Nevada, Sacramento, San Diego, and San Bernardino) (PDR # 5035940, 1355030, 1355032, 1355027, 1355031, 1311668, 1322007, 1322005, 1368633, 1322006).

The risk Scolytus schevyrewi would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Scolytus schevyrewi is already present in at least 13 counties in California, from Lassen County in the north to San Diego County in the south. The beetle is also widely distributed over much of the rest of the continental United States.  This suggests it has the potential to become established over much or most of the state of California.  Elms are widely planted in California.  Therefore, Scolytus schevyrewi 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: Even though Scolytus schevyrewi has not been reported to attack trees other than a few species of Ulmus in the United States, it is also reported to attack trees in the Rosaceae in its native range. Therefore, it 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: Scolytus schevyrewi is capable of sustained flight and it infests wood and wood products that could be moved (e.g. firewood). 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: There does not appear to be any significant economic damage associated with schevyrewi in California, even though it is present over a large portion of the state.  Elms are not a major timber tree, and the genus Prunus, which includes important fruit trees, does not appear to be affected in the United States.  Therefore, it receives a Low (1) in this category.

Economic Impact:  E

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: Scolytus schevyrewi does not appear to have had a significant environmental impact in California, even though it is widely distributed in the State. Elms (Ulmus) are not native to California, and these are the only trees reported as being impacted by this beetle in the United States.  Even though there do not appear to be many reports of this beetle damaging planted elms in the state, it is possible that this could occur during periods of drought.  Therefore, it receives a Medium (2) in this category.

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 Scolytus schevyrewi: 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: Scolytus schevyrewi has already spread to at least 13 counties in California.  The full extent of its distribution in the state is not known, and it is likely that its distribution will continue to expand.  The current range represents a large enough area to consider the species fully established for the purposes of this pest rating proposal.  It receives a High (-3) 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 (7)

Uncertainty:

The host range of S. schevyrewi in the United States was considered, for the purposes of this pest rating proposal, to be significantly narrower than what has been reported for this species’ native distribution.  This was based on the available information.  Because S. schevyrewi is already so widespread in the United States, it seemed that, if it had a broader host range in this country, it would have been reflected in the literature, especially considering how much attention this species has received.  It is possible that S. schevyrewi does attack other genera and/or species of trees in the United States, but this has escaped attention.

Conclusion and Rating Justification:

When it was initially determined, in the mid-2000s, that Scolytus schevyrewi was present in the United States, there was much concern regarding the possible impact of this species on elms (and possibly on fruit trees as well).  However, over a decade has elapsed and there is very little evidence of major economic or environmental impacts resulting from the species.  It is apparently already widely distributed in California, and there is little evidence of significant impacts in the state.  A “C” rating is justified.

References:

Campos-Bolaños, R., Atkinson, T.H., Cibrian-Tovar, D., and T. Méndez-Montiel.  2015.  Primer registro de Scolytus schevyrewi Semenov 1902 (Coleoptera: Curculionidae: Scolytinae) en Mexico.  Acta Zoologica Mexicana.  31(1): 146-148.

LaBonte, J.R.  2010.  The banded elm bark beetle, Scolytus schevyrewi Semenov (Coleoptera, Curculionidae, Scolytinae) in North America; a taxonomic review and modifications to the Wood (1982) key to the species of Scolytus Geoffroy in North and Central America.  ZooKeys.  56: 207-218.

Lee, J.C., Negrόn, J.F., McElwey, S.J., Witcosky, J.J., and S.J. Seybold.  2006.  Pest Alert: Banded elm beetle – Scolytus schevyrewi.  United States Department of Agriculture.  https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_026555.pdf

Negrόn, J.F., Witcosky, J.J., Cain, R.J., LaBonte, J.R., and Duerr II, D.A., McElwey, S.J., Lee, J.C., and S.J. Seybold.  2005.  The banded elm bark beetle: A new threat to elms in North America.  American Entomologist.  51(2): 84-94.

Seybold, S.J., Penrose, R.L., and A.D. Graves.  2016.  Chapter 21: Invasive bark and ambrosia beetles in California Mediterranean forest ecosystems.  In Paine, T.D. and F. Lieutier (Eds.), Insects and Diseases of Mediterranean Forest Systems (pp. 583-662).  Springer.

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 Drive, Sacramento CA 95833, (916) 654-1211;  plant.health[@]cdfa.ca.gov.

Comment Period:* CLOSED

1/16/2018 – 3/2/2018

*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

Coleoptera, Insects, Mites & Earthworms

Small Spruce Bark Beetle | Polygraphus poligraphus (L.)

California Pest Rating for
Small Spruce Bark Beetle |  Polygraphus poligraphus (L.)
Coleoptera
Pest Rating: A

 

PEST RATING PROFILE

Initiating Event:

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

History & Status:

Background: Polygraphus poligraphus has been reported to feed on Norway spruce (Picea abies) and Scotch pine (Pinus sylvestris).  Apparently, it prefers weakened trees but can attack healthy ones as well.  Healthier trees may be attacked when population levels of the beetle are high, probably because tree defenses can be overwhelmed through mass attack.  Polygraphus poligraphus, like many or most bark beetles, is associated with multiple species of fungi, and some of these may be pathogenic to trees.

Worldwide Distribution: Polygraphus poligraphus is native to Europe and has a wide distribution there, being found from Scandinavia to the Mediterranean and Eastern Europe.

Official Control: Although this species is considered a pest, it does not appear to be under official control in any country.

California Distribution:  This species is not known to be present in California.

California Interceptions: Polygraphus poligraphus has apparently been intercepted one time in California, on wood from Belgium or Germany (PDR # 798650).

The risk Polygraphus poligraphus would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Although Polygraphus poligraphus has a wide distribution in Europe, extending from northern Europe to the Mediterranean, it appears that climates represented by much of its distribution may be colder than what is present in most of California. However, spruce and pine trees occur throughout California and are potential host trees of this beetle.  Therefore, Polygraphus poligraphus receives a Medium (2) 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: Polygraphus poligraphus is known to attack at least two genera of coniferous trees. Therefore, it 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: Polygraphus poligraphus is capable of sustained flight. The species can also be artificially dispersed via movement of wood (including wood packing), as shown in one study where poligraphus emerged in a Canadian quarantine facility from wood packing from Norway.  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: There are challenges to predict the possible economic impact of Polygraphus poligraphus.  The literature suggests that living trees are attacked by this species, and multiple species of fungi (some of them apparently pathogenic) can be vectored by it.  If established, poligraphus could reduce the quality and/or yield of timber, which could result in the loss of markets for California timber.  Therefore, it receives a High (3) in this category.

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: As stated above, there is evidence that Polygraphus poligraphus attacks living trees and could vector harmful fungi. This could have a significant impact on California forest ecosystems.  There are several rare pines in California that could be impacted by the establishment of this beetle.  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 Polygraphus poligraphus: Medium (12)

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: Polygraphus poligraphus 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 (12)

Uncertainty:

Polygraphus poligraphus is a bark beetle that primarily feeds on trees that are damaged or weakened, but some sources suggest that it can attack healthy trees.  Hence, the impact of this species on natural and managed forests in California is difficult to predict.  There is a possibility that the ability of P. poligraphus to overcome the defenses of healthy trees and the impact of its vectored fungi (as well as any interactions between this beetle and fungi already present in California) in California could be different from what is seen in Europe.

Conclusion and Rating Justification:

As mentioned above, there are uncertainties regarding the possible impact of this species.  However, the fact that it does not yet occur in California, the evidence that it can (at least in some situations) attack living trees, and the fact that it can vector fungi suggest that an “A” rating is justified.

References:

Allen, E.A. and L.M. Humble.  2002.  Nonindigenous species introductions: A threat to Canada’s forests and forest economy.  Canadian Journal of Plant Pathology.  24: 103-110.

Alonso-Zarazaga, M.A., Kníñek, M., and S. Vit.  2017.  Polygraphus poligraphus (Linnaeus).  Fauna Europaea version 2017.06 https://fauna-eu.org

Kärvemo, S., Björkman, C., Johansson, T., Weslien, J., and J. Hjälten.  2017.  Forest restoration as a double-edged sword: the conflict between biodiversity conservation and pest control.  Journal of Applied Ecology.  1-11.

Krokene, P. and H. Solheim.  1996.  Fungal associates of five bark beetle species colonizing Norway spruce.  Canadian Journal of Forest Research.  26: 2115-2122.

Vojtěch, O., Křenová, Z., and J. Rastislav.  2013.  Species of bark beetles (Scolytinae) collected in the Bohemian Forest at Smrčina/Hochficht two years after the Kyrill hurricane.  Silva Gabreta.  19(3): 149-164.

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 Drive, Sacramento CA 95833, (916) 654-1211;  plant.health[@]cdfa.ca.gov.

Comment Period:* CLOSED

1/16/2018 – 3/2/2018

*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;

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♦  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

Coleoptera, Insects, Mites & Earthworms

Strangulate Weevil | Trochorhopalus strangulatus (Gyllenhal)

California Pest Rating for
Strangulate Weevil | Trochorhopalus strangulatus (Gyllenhal)
Coleoptera
Pest Rating: A

 

PEST RATING PROFILE
Initiating Event:

Trochorhopalus strangulatus was recently reported to be established on the island of Hawaii (J. Matsunaga, pers. comm.).  The species is currently Q-rated, and a permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background:  Trochorhopalus strangulatus is a weevil that is widely distributed in tropical sugarcane-growing areas.  Adults are reported to be 6-10 mm in length and are black with a coating of short, brown/gold setae (Corbett, 1932; Hustache, 1920; J. Matsunaga, pers. comm.).  This species is considered a pest of sugarcane.  The larvae bore into and feed in the stalks of the plant (Magarey et al., 2002).  However, some reports suggest it is of minor significance.  For example, it is reported to primarily attack sugar cane that is damaged or weak in Fiji (Imperial Bureau of Entomology, 1920).  The beetle has been reported to attack coconut palm; details on the damage inflicted are sparse, but one report suggests this beetle may provide conditions allowing other, more serious pests to attack trees (Corbett 1932).  This species was also reported to be associated with, and possibly damage bananas, although no further details were found (Harmer, 1912; Mararuai, 2010).  Lastly, this species is apparently often found associated with dead palm trees (J. Matsunaga, pers. comm.).

Worldwide Distribution:  Trochorhopalus strangulatus is known from islands in the Indian Ocean (Republic of Seychelles and the Mascarene Islands), Southeast Asia (Indonesia and Philippines), Papua New Guinea, Fiji, and Hawaii (Hustache, 1920; Magarey et al., 2002; J. Matsunaga, pers. comm.; Pemberton, 1963; Senterre et al., 2011; Symbiota Collections of Arthropods Network).  The native distribution is unknown, although one report states it is indigenous to the Seychelles (Senterre et al., 2011).  The distribution has presumably been expanded as a result of cultivation and transport of sugarcane in Southeast Asia and Pacific islands, which began thousands of years ago, and it is assumed that at least some localities represent introductions (Artschwager and Brandes, 1958).

Official Control: Trochorhopalus strangulatus is not known to be under official control anywhere.

California Distribution:  Trochorhopalus strangulatus is not known to occur in California.

California Interceptions:  Trochorhopalus strangulatus has not been intercepted in California.

The risk Trochorhopalus strangulatus would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Trochorhopalus strangulatus has been reported to feed on sugarcane, banana, and palms. Of these, ornamental palms are the most obvious possible host plant in California, and they are present throughout much of the state.  Based on the current distribution of T. strangulatus (tropical areas), it appears unlikely that this species could become established in more than a very limited portion of California.  Therefore, this species 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: Trochorhopalus strangulatus is a pest of sugar cane, but has also been reported to attack coconut palm and bananas, which suggests at least three families of plants are fed upon. Unfortunately, details regarding feeding on these alternate host plants are lacking. Therefore, T. strangulatus 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: Trochorhopalus strangulatus presumably flies.  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 weevil is a pest of sugarcane and it has also been reported to attack banana and palms.  California industries that could be affected by the establishment of this weevil include ornamental palms and sugarcane.  Ornamental palms are a $70 million industry in California, and damage (including lowering of yield) to palms in nurseries could result if T. strangulatus became established in California (Hoddle).  Sugarcane is either currently being grown in, or is planned to be grown in the Imperial Valley, where a sugarcane-based sugar and biofuels initiative is underway.  If this weevil became established in the Imperial Valley, which may not be likely given its apparent restriction to tropical areas, it could lower yield of sugarcane there.  An extensive sugarcane industry exists in the southeastern United States, and the climate in that region would likely be more favorable for the establishment of this pest.  The possibility of the spread of this pest to the southeastern United States (and impact on sugarcane and palms there), as well as other countries, could lead to a loss of markets for ornamental palms from California.  Therefore, T. strangulatus receives a Medium (2) in this category.

Economic Impact: A, 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: If this weevil was introduced to California, it could potentially spread to groves of the only species of native California palm, Washingtonia filifera, although this is somewhat unlikely, considering that this weevil is apparently restricted to tropical areas and these palms occur in the desert. 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 Trochorhopalus strangulatus: 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: Trochorhopalus strangulatus 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:

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

Uncertainty:

There is a great deal of uncertainty regarding the feeding by this species on palms and banana.  A possibility that must be considered is that some of the feeding attributed to T. strangulatus could have been the result of another species misidentified as this one.  If this is the case, it means that the feeding habits of this species may be narrower than assumed in this rating proposal.  There is also uncertainty regarding the ability of this species to become established in California, apart from the issue of host plant.  This species is apparently restricted to areas with a tropical climate, and it appears unlikely to be able to become established in California, although parts of southern California could provide adequate conditions for it.  This beetle could become an established pest in parts of California.  A cautious approach has been taken here because of the ability of this species to attack living plants, as shown by its status as a sugar cane pest.

Conclusion and Rating Justification:

Trochorhopalus strangulatus is a tropical weevil that is not known to occur in California.  The beetle is a pest of sugarcane, and reports suggest it also attacks bananas and palms.  This species poses an economic and environmental risk to California.  For these reasons, an “A” rating is justified.

References:

Artschwager, E. and E.W. Brandes.  1958.  Agriculture Handbook 122: Sugarcane (Saccharum officinarum L.); origin, classification, characteristics, and descriptions of representative clones.  United States Department of Agriculture.  United States Government Printing Office.  307 pp.

Corbett, G.H.  1932.  Insects of coconuts in Malaya.  Bulletin General Series (Straits Settlements & Federated Malay States Department of Agriculture).  10: 1-106.

Harmer, S.F.  1912.  Department of Zoology.  VI.  Economic zoology.  Return, British Museum.  1912: 163-167.

Hoddle, M.  Has the South American palm weevil, Rhynchophorus palmarum, established in southern California?  University of California, Riverside, Center for Invasive Species Research.

Accessed: November 17, 2017 http://cisr.ucr.edu/palmarum.html

Hustache, A.  1920.  Curculionides des iles Mascareignes.  Annales de la Société entomologique de France.  89: 113-203.

Imperial Bureau of Entomology.  1920.  Series A: Agricultural.  Review of Applied Entomology.  8: 1-40.

Magarey, R.C., Suma, S., Irawan, Kuniata, L.S., and P.G. Allsopp.  2002.  Sik na binatang bilong suka – Diseases and pests encountered during a survey of Saccharum germplasm ‘in the wild’ in Papua New Guinea.  Proceedings of the Australian Society of Sugar Cane Technology.  24: 219-227.

Mararuai, A.  2010.  Market access of Papua New Guinea bananas (Musa sp.) with particular respect to banana fly (Bactrocera musae (Tryon)) (Diptera: Tephritidae).  Ph.D. thesis.  School of Natural Resource Sciences, Queensland University of Technology, Brisbane, Australia.  192 pp.

Pemberton, C.E.  1963.  Important Pacific insect pests of sugar cane.  Pacific Science.  17(2): 251-252.

Senterre, B., Henriette, E., Chong-Seng, L., Beaver, K., Mougal, J., Vel, T., and J. Gerlach.  2011.  Seychelles key biodiversity areas.  Output 1: List of species of special concern.  Report of Consultancy, UNDP-GEF project, Ministry of Environment of Seychelles, Victoria, Seychelles.  67 pp.

Symbiota Collections of Arthropods Network.  Accessed 20 November 2017. http://scan1.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 Drive, Sacramento CA 95833, (916) 654-1211;  plant.health[@]cdfa.ca.gov.

Comment Period:* CLOSED

1/11/2018 – 2/25/2018

*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

Coleoptera, Insects, Mites & Earthworms

Metamasius hemipterus (L.): West Indian Sugarcane Weevil

California Pest Rating for
Metamasius hemipterus (L.): West Indian Sugarcane Weevil
Pest Rating:  C
PEST RATING PROFILE
Initiating Event:

February 26, 2014, USDA distributed a Deregulation Evaluation of Established Pests (DEEP) report proposing to change the status of Metamasius hemipterus, West Indian sugarcane weevil, from actionable to non-actionable for the continental United States.  The weevil would remain actionable for Hawaii and the Pacific territories.  The insect is currently C-rated by CDFA, so a pest rating proposal is needed to determine future direction.

History & Status:

Background:  The larvae of Metamasius hemipterus are borers that tunnel through the stems and petioles of tropical plants, causing extensive damage3.   They are considered an economic pest in Florida3.  The weevil feeds primarily on coconut, banana, and sugarcane2; it usually attacks plants that are already damaged.  Secondary hosts include a variety of palms, lantana, pineapple, cassava, guava, sorghum, corn, and Mora excelsa1,2.  Metamasius hemipterus can spread long distances through commerce in infested plants and fruit, especially bananas.

Worldwide Distribution: Metamasius hemipterus appears to be native to Central America and/or northern South America1.  From there it has spread through much of the Caribbean and Cameroon, Congo, Equatorial Guinea, Gabon, and Nigeria in Africa.  It was found in Florida in 1984.

Official Control: Metamasius hemipterus is considered a quarantine pest in Europe2.

California Distribution:  There are specimens of Metamasius hemipterus in the California State Collection of Arthropods from the following counties:  Los Angeles, San Diego, San Francisco, Contra Costa, and Calaveras.

California Interceptions:  There is only one interception of Metamasius hemipterus recorded in the PDR database.  This was at the border station in Blythe in 2001 on bananas of unknown origin.  The weevil is frequently intercepted by USDA on bananas from Central and South America.

The risk Metamasius hemipterus (West Indian sugarcane weevil) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: The present distribution of Metamasius hemipterus corresponds to USDA plant hardiness zones 9-13. This corresponds to much of California.  The weevil receives a High(3) in this category.

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: Metamasius hemipterus is known to feed on 20 species of plants in 6 families.  The weevil receives a Medium(2) in this category.

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.

3) Pest Dispersal Potential: Metamasius hemipterus has a high reproductive rate, with each female laying an average of 500 eggs3.  The weevils are reported to not disperse long distances naturally, but they can spread long distances through commerce in infested plants or fruit, especially bananas.  Metamasius hemipterus receives a High(3) in this category.

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: Metamasius hemipterus is reported to be a pest of sugarcane and ornamental palms.  However, it is present in California and is not reported to lower crop yield, lower crop values, trigger lost markets, alter cultural practices, vector other organisms, or interfere with water supplies.  The weevil receives a Low(1) in this category.

Evaluate the economic impact of the pest to California using the criteria below. Score: 1

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: Metamasius hemipterus has entered California and is not known to lower biodiversity, disrupt natural communities, or change ecosystem practices.  It is not known to directly affect threatened or endangered species or disrupt critical habitats.  There are no reports of the weevil triggering treatment programs or altering cultural practices, home/urban gardening, or ornamental plants.  Metamasius hemipterus receives a Low(1) in this category.

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.

Score the pest for 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 Metamasius hemipterus (West Indian Sugarcane Weevil):  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: Metamasius hemipterus is thought to have established a widespread distribution in California.  The weevil receives a High(-3) 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: Low(7)

Uncertainty:

Historically some scientists have treated what is now known as Metamasius hemipterus as three distinct species2.  It is possible that there could be cryptic species in this group that are absent from California and more damaging than the weevil we have here.

Conclusion and Rating Justification:

Metamasius hemipterus is reported to be present in California and is not known to cause any significant economic or environmental impacts.  A C-rating is justified.

References:

1Culliney, T.W.  2014.  Deregulation Evaluation of Established Pests (DEEP); DEEP Report on Metamasius hemipterus (L.): West Indian Sugarcane Weevil.

 2European and Mediterranean Plant Protection Organization (EPPO) data sheet on Metamasius hemipterus.  https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CDwQFjAD&url=https%3A%2F%2Fwww.eppo.int%2FQUARANTINE%2FPest_Risk_Analysis%2FPRAdocs_insects%2Fdraft_ds%2F09-15171%2520DS%2520Metamasius%2520hemipterus.doc&ei=yRRQU8PBN8PmyQHaloC4Cw&usg=AFQjCNFWGRjZa4Q95nqilDkxnpstEbCwWw&bvm=bv.64764171,d.aWc

3Weissling, Thomas J. and Robin M. Giblin-Davis.  2013.  Featured Creatures: Silky Cane Weevil.  http://entnemdept.ufl.edu/creatures/orn/silky_cane_weevil.htm

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, 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

Coleoptera, Insects, Mites & Earthworms

Diaprepes abbreviatus (Diaprepes Root Weevil)

California Pest Rating for
Diaprepes abbreviatus (Diaprepes Root Weevil)
Pest Rating: B
PEST RATING PROFILE
Initiating Event:

On October 9, 2013, Nick Condos recommended that we run Diaprepes abbreviatus through our pest rating process to review its pest rating.

History & Status:

Background:  Diaprepes root weevils are well documented as a serious pest of citrus that have been the subject of numerous research programs.  This is reflected by more than 3,200 papers on Google Scholar.  The adult weevils feed on the leaves of a wide variety of plants.  They lay eggs in clusters of 30-265 between leaves.  Larvae hatch from the eggs and drop into soil, where they feed on roots.  They sometimes girdle structural roots or the root crown, leading to the death of plants.  In addition, larval feeding provides infection sites for plant pathogens, especially Phytophthora spp2.  The weevil can spread to new areas as any life stage on nursery stock or as adult hitchhikers on landscaping equipment or similar conveyances.

Worldwide Distribution: Diaprepes abbreviatus is native to the Caribbean.  It was accidentally introduced to Florida in 1964, presumably on nursery stock from Puerto Rico.  The weevil has since spread over most of the southern and central portions of the state.  It has more recently spread to Texas, Louisiana, and California, presumably via nursery stock.

Official Control: Diaprepes abbreviatus is not known to be under official control by any states or nations.

California Distribution:  Diaprepes abbreviatus has established in coastal areas of San Diego, Orange, and southern Los Angeles County.

California Interceptions:  Diaprepes abbreviatus have been found in nurseries and are sometimes intercepted on nursery stock from Florida and Puerto Rico.

The risk Diaprepes abbreviatus would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Cool winter temperatures are expected to limit the establishment of Diaprepes abbreviatus in California to most of San Diego and Imperial counties, eastern Riverside County, and coastal Orange and Los Angeles Counties1.  Dry soils are expected to further restrict where the weevil can establish within this endangered area3.  Diaprepes abbreviatus 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: Diaprepes abbreviatus is highly polyphagous; it has been documented feeding on 270 plant species in 59 families4.  The weevil 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: Female Diaprepes abbreviatus have an extremely high reproductive potential, laying an average of 5,000 eggs4.  The weevils are strong fliers but usually stay on the first host plant they encounter.  They can move long distances on nursery stock.  The weevil receives a High(3) 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: The weevil is well documented as a serious pest that feeds on a wide variety of agricultural crops including Citrus, strawberries, avocado, peach, pear, and vegetables5.  The weevil also feeds on a wide variety of ornamental plants that are popular in the nursery trade5.  Larval feeding damages roots and creates infection sites for plant pathogens such as Phytophthora spp2.  Diaprepes abbreviatus is not expected to lower crop value; however, it can be expected to increase production costs at farms and nurseries as growers are advised to use pesticide drenches for larvae and foliar sprays for adults and eggs4. Citrus growers in Florida spend up to $400/acre for combined Diaprepes and Phytophthora control6.  The weevil is not expected to trigger a loss of markets or significant changes to cultural practices.  The weevil is not known to vector another pestiferous organism, but larval feeding on roots does facilitate infection by plant pathogens such as Phytophthora spp..  The weevil is not injurious or poisonous to animals and is not expected to affect water supply.

Although Diaprepes abbreviatus has not been documented to have a significant economic impact in coastal southern California, these areas are considered marginal for the establishment of the species1.  Inland conditions of Imperial County are expected to be significantly more favorable to the species due to warmer winter soil temperatures1.  Nevertheless, the presence of the root weevil has already triggered some new treatments in San Diego County as at least one grove manager is Rancho Santa Fe is treating citrus with Imidacloprid7.  However, many growers in the area endangered by Diaprepes abbreviatus will already be treating with Imidacloprid to control Asian Citrus Psyllid, Diaphorina citri; they will therefore not be financially impacted by the weevil.  However, the root weevils are not expected to be controlled by the foliar treatments used by organic growers.  Additional chemical treatments can be expected in organic groves, increasing production costs.  Diaprepes abbreviatus receives a Medium(2) in this category.

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

Economic Impact:  B, E

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: Environmental impacts of Diaprepes abbreviatus in California are likely to be limited by cold temperatures and dry weather.  It is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  Nor is it expected to directly affect threatened or endangered species or critical habitats.  Residents of the infested areas in southern California have not been reporting weevils or damage, indicating that abbreviatus is not triggering new chemical treatments in the urban landscape.  However, as it establishes in new areas the weevil is likely to trigger additional treatments by nurseries as they meet standards of cleanliness.  It is also likely to trigger additional treatments in agricultural areas of San Diego, Riverside, and especially Imperial counties.  In Florida, growers and nursery owners use pesticide drenches for larvae and foliar sprays for adults and eggs4.  Diaprepes abbreviatus 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:

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 Diaprepes abbreviatus: 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: Diaprepes abbreviatus has established a widespread distribution in coastal areas of southern California (San Diego, Orange, and Los Angeles Counties). However, it has not fully established in the endangered area, particularly the agricultural production areas of San Diego, Riverside, and especially Imperial counties.  Diaprepes abbreviatus 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.

–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(9)

Uncertainty:

D. abbreviatus may negatively change agricultural cultural practices as growers might alter irrigation and fertilization practices to promote root growth in root weevil infested areas.  Ants are believed to be major predators of Diaprepes root weevil larvae.  It is possible that future ant control practices to facilitate establishment of the ACP parasitoid Tamarixia radiata will increase the damage caused by Diaprepes abbreviatus in Southern California.  It is also possible that root-feeding by weevil larvae will help weaken citrus trees, making them more susceptible to HLB when it arrives in California, facilitating an epidemic of that disease in the state.

It is also possible that existing treatments for Asian citrus psyllid, Diaphorina citri, will help preclude the establishment of Diaprepes abbreviatus in citrus production.    It is also possible that soil moisture in the agricultural production areas of San Diego, Imperial, and Riverside counties may be too low to sustain populations of Diaprepes abbreviatus.

Conclusion and Rating Justification:

Diaprepes abbreviatus has been established in southern California for seven years and has not spread beyond heavily irrigated coastal areas.  However, Imperial County is expected to be much more favorable for the weevils due to higher winter soil temperatures.  The weevil is likely to be managed by existing systemic treatments for Asian citrus psyllid in some conventional groves, but root feeding may increase the susceptibility of trees to pathogens such as Phytophthora spp..  The economic and environmental impacts of Diaprepes abbreviatus are likely to be limited to new chemical treatments and increased production costs in citrus groves, particularly in Imperial County.  A ‘B’ rating is justified.

References:

1Lapointe, S.L., D.M. Borchert, and D.G. Hall.  2007.  Effect of Low Temperatures on Mortality and Oviposition in Conjunction With Climate Mapping to Predict Spread of the Root Weevil Diaprepes abbreviatus and Introduced Natural Enemies. Environmental Entomology 36(1):73-82. http://www.nappfast.org/pest%20reports/Diaprepes.pdf

2Lapointe, S.L. 2000.  Thermal requirements for Development of Diaprepes abbreviatus (Coleoptera: Curculionidae).  Environmental Entomology 29(2):150-156.  http://www.crec.ifas.ufl.edu/extension/diaprepes/bibliography/PDF/EnvEnt292.pdf

3Lapointe, S.L. and J.P. Shapiro. 1999.  Effect of soil moisture on development of Diaprepes abbreviatus (Coleoptera: Curculionidae).  Florida Entomologist 82(2): 291-299.  http://www.fcla.edu/FlaEnt/fe82p291.pdf

4Grafton-Cardwell, E.E., K.E. Godfrey, J.E. Pena, C.W. McCoy, and R.F. Luck.  2004. Diaprepes Root Weevil.  University of California Division of Agriculture and Natural Resources Publication 8131.  http://anrcatalog.ucdavis.edu/pdf/8131.pdf

5Knapp, J.L., S.E. Simpson, J.E. Pena, and H.N. Ngg.  2005.  Diaprepes Root Weevil Host List.  University of Florida ENY-641.  http://edis.ifas.ufl.edu/pdffiles/IN/IN11900.pdf

6University of California-Riverside Center for Invasive Species Research website:  http://cisr.ucr.edu/diaprepes_root_weevil.html

7Atkins, Robert and Tracy Ellis.  Personal communications.

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.

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: B

Posted by ls

Coleoptera, Insects, Mites & Earthworms

Euwallacea sp. nr. fornicatus: Polyphagous Shot Hole Borer (PSHB)

California Pest Rating for
Euwallacea sp. nr. fornicatus: Polyphagous Shot Hole Borer (PSHB)
Coleoptera: Curculionidae
Pest Rating: B
PEST RATING PROFILE
Initiating Event:

In 2003 ambrosia beetles collected at the Whittier Narrows nature center in Los Angeles County were identified as Euwallacea fornicatus, tea shot hole borer, a new state record. In 2012 these beetles were found associated with a disease on avocado trees in Los Angeles County. Molecular analysis by UC Riverside revealed that the beetles are a distinct species from tea shot hole borer¹. They have been designated Euwallacea sp. nr. fornicatus, polyphagous shot hole borer (PSHB), pending species description. PSHB presently has a temporary rating of “Q”. A pest rating proposal is needed to determine future direction on this pest.

History & Status:

Background: PSHB is an ambrosia beetle that feeds on a wide variety of trees and other large plants. Mated adult females fly in search of a host tree. They bore into the trunk or branches and inoculate the wood with several species of fungi, including Fusarium euwallaceae². Eggs are deposited in these fungal-lined galleries and larvae consume the fungi. The larvae pupate inside the galleries. The sex ratio is heavily female biased. The few males that emerge mate with siblings in their gallery. Males may crawl to other galleries on the same plant but do not fly. Females are strong fliers and may fly in search of a new host. The females are known to feed on more than 200 species of plants, but only 30-40 of these plants have been confirmed as good reproductive hosts suitable for larval development. The fungal disease vectored by the adult female beetles may eventually kill the host tree. PSHB may disperse long distances when wood or nursery stock is moved.

Worldwide Distribution: Molecular evidence indicates that PSHB is native to Vietnam and other parts of southeast Asia¹. From there it has spread to Israel, South Africa, and California.

Official Control: PSHB is not known to be under official control in any states or nations. However, Euwallacea fornicatus is listed as a quarantine pest by Colombia, Honduras, Japan, South Korea, and Mexico³. All species of Euwallacea are considered quarantine pests by Japan and Peru³. These regulations are likely to also apply to PSHB.

California Distribution: PSHB has been found in the environment of Los Angeles, Orange, San Bernardino, and San Diego counties. Molecular analysis indicates that the population in San Diego County is a separate introduction of the species. A single beetle was trapped in Santa Cruz County but was not suitable for molecular analysis to determine if it was polyphagous shot hole borer or tea shot hole borer. Tea shot hole borer is present in Hawaii and occasionally intercepted.

California Interceptions: Fusarium euwallaceae was found in one California nursery, indicating that PSHB may have been present. Infected plants were destroyed. PSHB has never been intercepted at California’s borders. Unidentified beetles (Euwallacea sp. possibly fornicatus) have been intercepted seven times on bamboo, cut flowers, ginger, macadamia, and Draceana compacta from Hawaii. PSHB is not known to occur in Hawaii so these interceptions are likely tea shot hole borer.

The risk Euwallacea sp. nr. fornicatus (PSHB) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: PSHB has an extremely wide host range including many street trees and native species. Protected from the environment while inside trees, the beetle can be expected to establish wherever host trees are grown. It receives a High (3) in this category.

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) Known Pest Host Range: PSHB is highly polyphagous, feeding on over 200 species of trees. The 30-40 known reproductive hosts account for approximately 25% of street trees in southern California. New reproductive hosts are regularly discovered and the host range of this species can be expected to grow. PSHB receives a High (3) in this category.

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: PSHB is a strong flyer and in Israel has spread naturally 10-20km/year. Populations of the beetles may also spread long distances when infested wood or nursery stock is moved. The beetles also have a high reproductive rate. PSHB receives a High (3) 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: PSHB and its associated fungal pathogens can be expected to lower the yield of avocado groves and commercial forests by triggering dieback, large scale pruning of dead branches, and removal of dead trees. The damage caused by this pest is likely to increase crop production costs by triggering new pest management programs. Euwallacea fornicatus and Euwallacea sp. are listed as quarantine pests by several of California’s trading partners. The presence of this pest on consignments may disrupt trade. PSHB also vectors several fungal pathogens that may eventually lead to the death of host plants. PSHB receives a High (3) in this category.

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

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: PSHB vectors fungal pathogens that may lead to the death of a wide variety of slow-growing trees that are the foundation of forest ecosystems and an integral component of the urban environment. Damage from this pest is expected to have significant environmental impacts including disrupting natural communities and changing ecosystem processes. PSHB is likely to trigger additional official and private treatment programs. It is also likely to significantly impact cultural practices and ornamental plantings. PSHB receives a High (3) in this category.

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.

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 Euwallacea sp. nr. fornicatus (PSHB): High (15)

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: PSHB is known to be established in Los Angeles, Orange, San Bernardino, and San Diego counties. 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.

– 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: High (13)

Uncertainty:

A single specimen identified as Euwallacea fornicatus was trapped in Santa Cruz County in 2013. This could be PSHB, or it could be tea shot hole borer. Low density populations of PSHB are difficult to detect; it could be present in other parts of the state.

Conclusion and Rating Justification:

PSHB is expected to have significant economic and environmental impacts as it expands its range in California. However, an “A”-rating is not justified because the pest has been present in the state since 2003 and is not under official control. A “B”-rating is justified.

References:

¹Eskalen, Akif, R. Stouthamer, S.C. Lynch, P.F. Rugman-Jones, M. Twizeyimana, A. Gonzalez, and T. Thibault. 2013. “Host Range of Fusarium Dieback and Its Ambrosia Beetle (Coleoptera: Scolytinae) Vector in Southern California.” Plant Disease (97):938-951. http://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS-11-12-1026-RE

²Freeman, S., M. Sharon, M. Maymon, Z. Mendel, A. Protasov, T. Aoki, A. Eskalen, and K. O’Donnell. 2013. Fusarium euwallaceae sp. nov.—a symbiotic fungus of Euwallacea sp., an invasive ambrosia beetle in Israel and California. Mycologia 105(6): 1595-1606. http://www.ncbi.nlm.nih.gov/pubmed/23928415

³ USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.

Pest Rating:  B

Posted by ls 

Coleoptera, Insects, Mites & Earthworms

Brachypeplus basalis Erichson: A sap beetle

California Pest Rating for
Brachypeplus basalis Erichson: A sap beetle
Coleoptera: Nitidulidae
Pest Rating: B
PEST RATING PROFILE
Initiating Event:

Brachypeplus basalis has been found feeding on pollen and pollen substitutes inside beehives in California and other states several times since 2010 and is in need of a pest rating.

History & Status:

Background:  There is no information on the biology of Brachypeplus basalis.  Presumably, in Australia the beetle feeds on fungi and yeasts, but has also been found within beehives.  The species has now been found feeding on pollen in beehives in the United States several times.  Although pollen cannot be legally imported from foreign sources to feed bees, it can be imported for human consumption.  From 2002-2011 honeybees could also be imported from Australia.  It is likely that these beetles followed one of these pathways.

Worldwide Distribution:  Brachypeplus basalis is native to Australia and has never been recorded in the environment of any other nation.

Official Control:  Brachypeplus basalis is not known to be under official control in any other states or nations.

California Distribution:  Brachypeplus basalis has been detected in beehives in Solano, Orange (unofficial record), Tehama, and Shasta counties.  Brachypeplus basalis has never been collected outside beehives in California.

California Interceptions:  Brachypeplus basalis has not been intercepted at the border stations.

The risk Brachypeplus basalis would pose to California is evaluated below.

Consequences of Introduction:

1)  Climate/Host Interaction:  Beehives are found throughout California and are frequently moved. Brachypeplus basalis is likely to establish in beehives throughout the state. The beetle 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:  Brachypeplus basalis is currently only known to feed on pollen stores in beehives. The beetles 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 reproductive rate of Brachypeplus basalis is unknown; however, that of other Brachypeplus species indicates an average life cycle of 35 days (Cline et al. 2013) and suggests a multivoltine life cycle that is typical of other nitidulid species (Jelínek et al 2010). The beetles may travel long distances when beehives are moved, and are also capable of powered flight. The beetle receives a High (3) 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:  Brachypeplus basalis has the potential to lower yield in beehives by robbing pollen stores. If severe, this could reduce the availability of beehives and have further economic costs to industries that rely on pollination services.  The sap beetles may increase production costs in beehives as beekeepers may treat the pests.  The sap beetles may be injurious to agriculturally important animals (bees) by robbing pollen. Although the beetles are not under official control, their status as an emerging pest could lead to the establishment of quarantines in the future.  B. basalis receives a High (3) in this category.

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.
space
– 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:  Brachypeplus basalis may trigger additional treatment programs by beekeepers. The sap beetles receives a Medium (2) in this category.

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 Brachypeplus basalis: Medium(12)

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:  Brachypeplus basalis is only known from incursions in beehives; it has never been found in the environment.  However, there have been no formal surveys for the beetle.  The sap beetles receive 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:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)

Uncertainty:

It is possible that the presence of Brachypeplus basalis may affect the markets for queen bee exports from California. There are stingless bees in California that could be negatively affected by the introduction of these beetles. There have not been any formal surveys for the sap beetles so they are likely much more widespread, perhaps across the entire United States.  If this is the case, it is possible that the beetle is already successfully managed by beekeepers and of no economic significance.

Conclusion and Rating Justification:

Brachypeplus basalis may have significant economic impacts but environmental impacts are likely to be limited to chemical treatment of beehives.   A “B” rating is justified.

References:

Andy Cline (Andrew.Cline@cdfa.ca.gov)

Cline, A.R., P.E. Skelley, S.A. Kinnee, S. Rooney-Latham, and P. Audisio. 2013. Multi-trophic interactions between a sap beetle, Sabal palm, scale insect, fungi, and yeast, as well as discovery of a compound with antifungal properties. PLOS-One. [In Review: MS# PONE-D-13-37799]

Jelínek, J., C.E. Carlton, A.R. Cline, & R.A.B. Leschen. 2010. Nitidulidae Latrielle, 1802. Pp. 390-407. In Leschen, R.A.B., R.G. Beutel, & J.F. Lawrence (eds.) Handbook of Zoology. Volume IV. Arthropoda: Insecta. Part 38. Coleoptera, Beetles. 786pp.

Responsible Party:

Jason Leathers, 1220 “N” Street, Room 221, Sacramento, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov

 Pest Rating: B

Posted by ls

Coleoptera, Insects, Mites & Earthworms

Oulema melanopus (Linnaeus): Cereal Leaf Beetle

California Pest Rating for
Adult Cereal Leaf Beetle (Oulema melanopus) Image Citation: Hania Berdys, bugwood.org
Adult Cereal Leaf Beetle (Oulema melanopus)
Image Citation: Hania Berdys, bugwood.org
Oulema melanopus  (Linnaeus): Cereal Leaf Beetle
Coleoptera: Chrysomelidae
Pest Rating: B
PEST RATING PROFILE
Initiating Event:

During late summer 2013, populations of Cereal Leaf Beetle (CLB) were found in Siskiyou and Modoc counties. Nick Condos recommended a new pest rating proposal for CLB to help determine the path forward.

History & Status:

Background: CLB is a pest of grain crops that commonly feeds on the leaves of oats, wheat, and barley. It is also reported to feed on rye, millet, corn, and many types of wild grasses. Rice is also sometimes listed as a host, but there is no evidence that CLB causes damage to rice in the scientific literature nor is CLB included in IPM guidelines for rice-producing states. Most of the damage is caused by larval beetles, known as “slugs”, feeding in the spring. Damage to leaves results in reduced photosynthetic ability in the plants and can significantly reduce grain yield. When ready to pupate, larvae drop into the soil. Adults emerge in the summer and feed briefly before entering summer aestivation. The beetles then seek out overwinter sites among the shelter of protected places such as debris and leaf litter. Historically CLB has sometimes caused severe crop losses; however, in most of the United States CLB populations are so effectively managed by introduced biological control agents, especially Tetrastichus julis, that chemical treatment is seldom required.

Worldwide Distribution:  CLB is native to Europe. It was detected in Michigan in 1962 and has since spread over much of the United States. It was detected in Oregon in 1999 and by 2013 had spread to within 11 miles of the California border.

Official Control:  CLB is listed as a regulated quarantine pest in New Zealand1, Japan2, and possibly other countries.

California Distribution:  CLB has been found in the environment of Siskiyou and Modoc counties.

California Interceptions:  CLB is commonly intercepted at California’s border stations on items such as beehives, potted plants, lumber, etc.

The risk CLB would pose to California is evaluated below.

Consequences of Introduction:

1)  Climate/Host Interaction:  In California, climate models suggest that CLB will only find favorable conditions in Del Norte County, Humboldt County, and a small portion of the central San Joaquin Valley4. Conditions in the southern half of California are predicted to be especially unfavorable to establishment of CLB.  CLB receives a Medium (2) 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:  CLB feeds on six different varieties of field crops and wild grasses. It 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:   CLB only has one generation per year, but is capable of reaching damaging populations relatively quickly, in the absence of biological control agents. With help from the wind the beetles are thought to spread up to 10 miles/year on their own. They may move longer distances as hitchhikers on items such as lumber or beehives; however, evidence indicates that they are not likely to establish populations through this movement.  According to NAPIS county records all CLB spread has been along the leading edge of the population from the original introduction, with the exception of one jump across the Dakotas3.  Furthermore, wheat producing states such as Arizona and Texas do not have exterior quarantines against CLB and do not have the pest. The fact that CLB typically do not mate until after overwintering may help explain this, as mated females are unlikely to be transported while overwintering.  CLB 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: Provided that biological control agents are introduced in California, CLB is not expected to significantly lower crop yield. CLB may increase crop production costs as fields will need to be scouted for the slugs to assess parasitism rates and growers may occasionally need to treat. CLB is considered a quarantine pest in some nations and could therefore, in some cases, trigger interruptions to trade or the implementation of new phytosanitary measures. CLB is not expected to negatively change normal cultural practices. CLB does not vector any other organisms, is not injurious or poisonous to agriculturally important animals, and does not interfere with water supplies. CLB receives a Medium (2) in this category.

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

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:  CLB may require some new private treatment programs in California in the absence of biological control agents or in cases where the parasitism rate is found to be low.  CLB is not expected lower biodiversity, disrupt natural communities, or change ecosystem processes.  CLB is not expected to directly impact threatened or endangered species.  CLB is not expected to disrupt critical habitats.  CLB is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings.  CLB receives a Medium (2) in this category.

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 CLB: 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:  Well established populations of CLB have been found in Siskiyou and Modoc counties. CLB receives a Low (-1) 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:

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

Uncertainty:

It is possible that CLB will attain a wider distribution within California than is predicted by climate models. It is also possible that several species of threatened and endangered native grasses could be favorable hosts for CLB, leading to additional environmental impacts. Furthermore, CLB populations may have established in other parts of California.

Conclusion and Rating Justification:

Provided that biological control agents are introduced to California, economic impacts from CLB are expected to be limited at most to additional pest scouting, occasional treatment, and possibly limited impacts on international trade.  Environmental impacts are expected to be limited to occasional chemical treatments in cases where CLB parasitism rates are found to be low.  CLB that are transported in trade nearly always fail to establish populations, showing that quarantines do not play much of a role in limiting CLB dispersal.  A “B” rating is justified.

References:

1 http://www.mpi.govt.nz/biosecurity-animal-welfare/pests-diseases/boric.aspx
2 http://www.pps.go.jp/english/law/list1.html
3 http://pest.ceris.purdue.edu/map.php?code=INAMCMA#
4 Risk assessment for cereal leaf beetle in California through the movement of small grains, Christmas trees, and farm equipment. USDA-APHIS. 2007.

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.

 Pest Rating: B

Posted by ls