Category Archives: Coleoptera

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:

♦  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

Aromia bungii (Redneck Longhorn Beetle)

California Pest Rating for
Aromia bungii  (Redneck Longhorn Beetle)
Coleoptera:  Cerambycidae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:  

The EPPO reporting service distributed a report by email on October 24, 2013.  The report included records of Aromia bungii (Coleoptera: Cerambycidae) being found for the first time in Lombardia region, Italy and Aichi Prefecture, Japan.  The beetle was previously intercepted in Washington State and is a fruit tree pest that feeds on a variety of trees that are specialty crops of major economic importance in California.  Aromia bungii is an invasive pest that is currently spreading in international trade and in need of a pest rating.

History & Status:

Background:  Aromia bungii is a wood boring beetle that feeds on a variety of trees.  Adult beetles lay eggs in bark crevasses of healthy to slightly stressed trees.  The larvae bore galleries in the trunk and branches, leading to decreased fruit production and weakening of the trees1.  In China the main host plants are species of Prunus (Rosaceae), especially peach (Prunus persica) and apricot (P. armeniaca), and to a lesser extent plum (P. domestica) and cherry (P. avium)1.  Other hosts include damson plum (P. domestica spp. institia), Japanese apricot (P. mume), Korean cherry (P. japonica), neem (Azadirachta indica (Meliaceae)), weaver’s bamboo (Bambusa textilis (Poaceae)), persimmon (Diospyros virginiana (Ebenaceae)), olive (Olea europea (Oleaceae)), white poplar (Populus alba (Salicaeae)), Chinese white poplar (P. tomentosa), Chinese wingnut (Pterocarya stenoptera (Juglandaceae)), pomegranate (Punica granatum (Lythraceae)), and Schima superba (Theaceae)1.   In 2008 A. bungii was intercepted in a manufacturing plant in Seattle that imports products from China and Taiwan and in wooden pallets in a warehouse in the United Kingdom, demonstrating that it can move in international trade.

Worldwide Distribution: Aromia bungii is native to the temperate regions of China.  It has spread throughout China, North Korea, South Korea, Mongolia, Vietnam, and Taiwan.  Recently it has been found feeding on fruit trees in the environment of two European nations where it is under eradication:  Germany (2011) and Italy (2012).  In June 2013 the beetle was confirmed to be established in Aichi Prefecture, Japan.

Official Control: Aromia bungii is under official control in Europe.

California Distribution:  Aromia bungii has never been found in the environment of California.

California Interceptions:  Aromia bungii has never been found in any regulatory situations in California.

The risk Aromia bungii would pose to California is evaluated below.

Consequences of Introduction:  

1) Climate/Host Interaction: Plant Hardiness zones where Aromia bungii is known to be established range from approximately zones 4 through 11, indicating that the beetle is likely to find a favorable climate in California. Furthermore, host trees of the beetle are commonly grown commercially and as ornamentals in the state.  The beetle 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: Aromia bungii is known to feed on 12 species of plants in nine plant families.  The beetle 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: The reproductive rate is not well known in China, but generations are said to take 2-3 years.  Adult beetles are relatively strong fliers and eggs, larvae, and pupae can be spread long distances by humans when wood or plants are moved.  Aromia bungii receives a Medium(2) in this category.

Evaluate the natural and artificial dispersal potential of the pest:

Score: 2

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

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

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

4) Economic Impact: If Aromia bungii were to establish in California it is expected to reduce crop yields, increase production costs, and possibly lead to quarantines.  It might also negatively change cultural practices.  The beetle receives a High(3) in this category.

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

Economic Impact: A, B, C, D

A. The pest could lower crop yield.

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

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

D. The pest could negatively change normal cultural practices.

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

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

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

Economic Impact Score: 3

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

– Medium (2) causes 2 of these impacts.

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

5) Environmental Impact: If Aromia bungii were to establish in California it would be expected to trigger additional official and private treatment programs.  It would also significantly impact home/urban gardening and ornamental plantings as unmanaged host trees may be killed and many of the known host trees are common in the urban landscape.   The beetle receives a High(3) in this category.

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

Environmental Impact: 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:

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 Aromia bungii:  High(13)

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

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Aromia bungii has never been detected in California. It receives a Not established(0) in this category.

Score: 0

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

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

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

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

Final Score:

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

Uncertainty:

The host range of Aromia bungii may be much greater than is known.  It may have a higher reproductive potential (i.e. shorter generation time) in California than is reported in northern China.

Conclusion and Rating Justification:

Aromia bungii poses an economic threat to the stone fruit, persimmon, and pomegranate industries in California.  It also poses a threat to the environment as host trees are common in the urban landscape.  The arrival of the beetle is likely to trigger additional chemical treatments and/or the death of trees.  An “A” rating is justified.

References:

1EPPO Alert List.  http://www.eppo.int/QUARANTINE/Alert_List/insects/Aromia_bungii.htm

2The Food & Environment Research Agency.  Rapid Pest Risk Analysis for Aromia bungii.  http://www.fera.defra.gov.uk/plants/plantHealth/pestsDiseases/documents/aromiaBungii.pdf

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: A

Posted by ls

Coleoptera, Insects, Mites & Earthworms

Aethina tumida Murray: Small Hive Beetle (SHB)

small-hive-beetle-byJeffreyLoft-FloridaAg-bugwood
California Pest Rating for
Aethina tumida Murray: Small Hive Beetle (SHB)
Coleoptera: Nitidulidae
Pest Rating:  B
PEST RATING PROFILE
Initiating Event:

On September 12, 2016 Stephen Brown requested a rating proposal for Aethina tumida, small hive beetle.

History & Status:

Background:  Adult small hive beetles can fly for several miles in search of beehives.  Upon locating a hive, the adult beetles enter and seek out protected cracks and crevices1 within the hive environment.  They are able to feed by rubbing bees with their antennae and inducing the bees to regurgitate food1.  The beetles lay eggs in the hives.  Larvae that hatch feed on honey, pollen, and bee brood1.  Once mature they migrate out of the hive and enter the soil to pupate1.  SHB can spread long distances by flying and via transport of infested hives.

Worldwide Distribution: SHB is native to sub-Saharan Africa1.  From there it has spread to Australia, Italy, Brazil, and the United States1,3,4.  The species was first found in the United States in Florida in 1998 but specimens indicate it had been present since 19961.

Official Control: Aethina tumida is listed as a harmful organism by Antigua and Barbuda, Grenada, and Taiwan2.  The EU also restricts SHB infested equipment and hives.

California Distribution:  SHB is occasionally found in beehives in southern California and the bay area.

California Interceptions:  SHB is frequently intercepted in beehives entering California from other states.

The risk Aethina tumida (small hive beetle (SHB)) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Beehives are kept throughout most of California and SHB is likely to establish wherever they are found. SHB 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: SHB is only known to feed in beehives and receives a Low (1) 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: SHB has very high reproductive potential.  Each female can lay 1,000-2,000 eggs1.  They can disperse long distances by flying and when infested hives are moved.  SHB 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: SHB has the potential to increase crop production costs by decreasing the number of hives available for pollination services.  Beekeepers are advised to alter cultural practices to limit damage from the pest1.  SHB also harms bees by feeding on bee brood, honey, and pollen in hives.  SHB 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: SHB is not known to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It is not likely to directly affect threatened or endangered species or disrupt critical habitats.  It may trigger new chemical treatments by beekeepers.  It is not known to impact cultural practices, home/urban gardening, or ornamental plantings.  SHB receives a Medium (2) 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 Aethina tumida (Small Hive Beetle (SHB)):  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: SHB is occasionally found in beehives in many parts of California, but much of northern California remains free from the pest. SHB 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: Medium (10)

Uncertainty:

There have not been any recent formal surveys for SHB in California.  It is possible that the beetle has a more widespread distribution in the state. There have not been any studies to determine if SHB may affect native bees in CA.

Conclusion and Rating Justification:

SHB is likely to have significant economic and environmental impacts in California.  However, it is considered to be established in parts of the state.  A “B” rating is justified.

References:

1 Ellis, James D. and Amanda Ellis.  2013. University of Florida Featured Creatures.  http://entnemdept.ufl.edu/creatures/misc/bees/small_hive_beetle.htm

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

3 Mutinelli, F., F. Montarsi, G. Federico, A. Granato, A. Maroni Ponti, G. Grandinetti, N. Ferre, S. Franco, V. Duquesne, M. Pierre Riviere, R. Thiery, P. Henrikx, M. Ribiere-Chabert, and M. Pierre Chauzat. 2014. Detection of Aethina tumida Murray (Coleoptera: Nitidulidae) in Italy: outbreaks and early reaction measures. Journal of Apicultural Research 53: 569-575.

4 Official OIE website for Brazil. http://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFullEventReport&reportid=19529

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

Stenhomalus taiwanus Matsushita: Taiwan Slender Longhorned Beetle

California Pest Rating for
Stenhomalus taiwanus Matsushita: Taiwan Slender Longhorned Beetle
Coleoptera: Cerambycidae
Pest Rating:  A
PEST RATING PROFILE
Initiating Event:

In September 2016 the United States Department of Agriculture (USDA) New Pest Advisory Group (NPAG) released a report on Stenohomalus taiwanus that recommended that USDA establish a non-reportable/non-actionable port policy for the beetle in the continental United States.  The beetle would remain actionable in Hawaii and the United States territories.  Stephen Brown requested comments on this proposal.

History & Status:

Background:  Stenhomalus taiwanus is a longhorned beetle that is only known to feed on stems and branches of two to five year old Zanthoxylum bungeanum (Sichuan pepper, Chinese pepper) and Zanthoxylum piperitum (Japanese prickly ash).  Stenhomalus taiwanus has only one generation per year.  Adult beetles emerge in summer and crawl on branches and leaves and may fly short distances.  Larvae feed on the cortex and xylem of the tree where they overwinter and pupate in spring.  The beetles may be transported long distances inside wood when infested plants or freshly cut stems and branches are moved.

Worldwide Distribution: Stenhomalus taiwanus is native to China, Japan and Taiwan.  The only place it is known to have invaded is the southern United States, where it has been found in Georgia, Alabama, and Texas.

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

California Distribution:  Stenhomalus taiwanus has never been found in the environment of California.

California Interceptions:  Stenhomalus taiwanus has never been found in any regulatory situations in California.

The risk Stenhomalus taiwanus (Taiwan slender longhorned beetle) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: There are no species of Zanthoxylum native to California and those plants are only occasionally cultivated here. If Stenhomalus taiwanus were to establish in California its distribution is likely to be very limited.  It receives a Low (1) 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: Stenhomalus taiwanus is only known to feed on two species of plants in one genus.  It receives a Low (1) 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: Stenhomalus taiwanus only has one generation per year.  It can be transported long distances when infested plants or fresh stems or branches are moved.  It receives a Medium (2) 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: Stenhomalus taiwanus has been present in the southern United States for more than five years and has not had any economic impacts.  If it were to establish in California it is not likely to lower crop yields, increase crop production costs, disrupt markets, negatively change cultural practices, vector other organisms, injure animals, or interfere with water supplies.  It receives a Low (1) 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: If Stenhomalus taiwanus were to establish in California it is not likely to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It is not expected to affect threatened or endangered species or disrupt critical habitats.  It may trigger new treatment programs by residents who grow ornamental Zanthoxylum  In California the beetle is not likely to significantly affect cultural practices, home/urban gardening, or ornamental plantings.  Stenhomalus taiwanus receives a Medium (2) 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 Stenhomalus taiwanus (Taiwan Slender Longhorned Beetle):  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: Stenhomalus taiwanus has never been found in California and receives a Not established (0) in this category.

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

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

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

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

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

Final Score:

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

Uncertainty:

Stenhomalus taiwanus does not respond to any wood boring beetle lures and would not be found by CDFA’s exotic wood borer surveys.  In the South it is most commonly collected at light traps.  There have not been any recent comprehensive light trap surveys of California.  Interception data and finds from other states indicate that the beetle has been moving into the United States in wood products from China.  It is certain that some of these infested products also entered California.  Furthermore, it is likely that Stenhomalus taiwanus has already entered California and remains undetected.

            Although the beetle is only documented to feed on two species of Zanthoxylum, it is not known what plant(s) the beetle is using as a host in the United States.  It has been intercepted on “willow” baskets from China.  It is unknown what type of wood this actually was.  If there has been host-switching there is potential for far-reaching forestry and environmental impacts.

Conclusion and Rating Justification:

If Stenhomalus taiwanus were to establish in California it is only expected to affect ornamental Zanthoxylum plants.  However, there is significant uncertainty about what host plant(s) the beetle is using in the United States as its native hosts do not occur here except as occasional ornamentals.   Until more information about the host range of this beetle is known or it is found in California an “A” rating is justified.

References:

Newton, Leslie and David Bednar. 2016.  NPAG Report Stenhomalus taiwanus Matsushita: Taiwan slender longhorn beetle.  United States Department of Agriculture New Pest Advisory Group.

Responsible Party:

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

Pest Rating:  A

Posted by ls

Coleoptera, Insects, Mites & Earthworms

Ananca bicolor (Fairmaire): Red-Black False Blister Beetle

California Pest Rating for
Ananca bicolor (Fairmaire): Red-Black False Blister Beetle
Coleoptera: Oedemeridae
Pest Rating:  B
PEST RATING PROFILE
Initiating Event:

The false blister beetle Ananca bicolor was recently intercepted by CDFA’s high risk programs on a shipment of Plumeria cut flowers from Hawaii.  The beetle is presently assigned a temporary rating of “Q”.  A pest rating proposal is required to support a permanent pest rating.

History & Status:

Background:  Ananca bicolor adults are nocturnal and highly attracted to lights1,2.  They are considered a nuisance pest and may enter dwellings in large numbers.  The adult beetles feed on pollen.  The larvae are not well documented but similar beetle grubs feed on rootlets and rhizomes3.  Ananca bicolor may be transported long distances when infested cut flowers are moved or as a contaminating pest.

Worldwide Distribution: Ananca bicolor is Polynesian in origin4.  It is known to be established in Samoa, Tahiti, Marquesas, Tonga, Ellice Island, and New Hebrides4.  It invaded Hawaii sometime before 18854.

Official Control: Ananca bicolor is not listed on any nations’ harmful organisms lists5 and is not known to be under official control anywhere.

California Distribution:  Ananca bicolor has never been found in the environment of California.

California Interceptions:  Ananca bicolor has been intercepted by CDFA four times. Three interceptions were on cut Plumeria flowers from Hawaii and one was on green vegetables.

The risk Ananca bicolor (Red-black false blister beetle) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Ananca bicolor is only known to be established on tropical islands.  Almost all oedemerid larvae are limited to wet/moist environments.  This indicates that if the beetle were to establish in California it is likely to be limited to warm coastal areas.  It receives a Low (1) 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: Ananca bicolor adults are polyphagous on a wide variety of pollen.  Grubs are presumed to be equally polyphagous on organic matter in soil.  The beetle 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: In Hawaii Ananca bicolor occurs in large numbers indicating that it likely has a high reproductive rate.  Despite its abundance and more than a century of transoceanic commerce, Ananca bicolor has not spread beyond Polynesia, indicating that it does not often spread via trade.  Ananca bicolor receives a Medium (2) 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: If Ananca bicolor were to establish in California it is not expected to lower any crop yields.  It may lower the value of cut flowers and flowering nursery stock by contaminating plants with its presence.  It is not likely to trigger lost markets, change cultural practices, vector other organisms, injure animals, or interfere with water supplies.  Ananca bicolor receives a Low (1) 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: If Ananca bicolor were to establish in California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It is not likely to directly affect threatened or endangered species or disrupt critical habitats.  Since adult beetles are attracted to lights in large numbers, they may trigger new private treatment programs by residents who find them to be a nuisance.  The beetles are not likely to have significant impacts on cultural practices, home/urban gardening, or ornamental plantings.  Ananca bicolor receives a Medium (2) 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 Ananca bicolor (Red-Black False Blister Beetle):  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: Ananca bicolor has not been found in California and receives a Not established (0) in this category.

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

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

Final Score:

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

Uncertainty: 

California does have a rich oedemerid and melyrid fauna, which would be the direct competitors of Ananca bicolor.  If this new beetle were to establish in California it might outcompete and displace these native beetles.  It is possible that Ananca bicolor may be able to adapt to wider variety of climates and colonize a larger part of California.

Conclusion and Rating Justification:

Ananca bicolor has never been found in California and is likely to have impacts on the cut-flower and nursery industries and become a nuisance to residents if it were to establish in the state.  A “B” rating is justified.

References:

1 Kinsey, Beth T. 2015. Red-black False Blister Beetle.  The Firefly Forest.  http://fireflyforest.net/firefly/2009/07/08/red-black-false-blister-beetle/

2 Tenorio, JoAnn M. and Gordon M. Nishida. 1995. What’s Bugging Me?: Identifying and Controlling Household Pests in Hawaii. University of Hawaii Press. 184pp.  https://books.google.com/books?id=2ehBWyagf2gC&pg=PA69&lpg=PA69&dq=Ananca+bicolor&source=bl&ots=ROFVnohzQs&sig=K-jbQylsU-8-EjiOcwGtf-8ARV8&hl=en&sa=X&ei=-HaMVdjENIvooAS00r24Dw&ved=0CEAQ6AEwBzgK#v=onepage&q=Ananca%20bicolor&f=false

3 Arnett, Ross H. Jr. 2014. Common Name: False Blister Beetles. University of Florida Featured Creatures. http://entnemdept.ufl.edu/creatures/urban/medical/false_blister_beetles.htm#top

4 Swezey, O.H. 1939. Notes on Oedemeridae in Hawaii and Palmyra. Proc. Haw. Ent. Soc. 10(2):263-264.  http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/15990/PHES10_263-264.pdf?sequence=1

5 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.

Comment Format:

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

Example Comment: 

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

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♦  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

Dactylotrypes longicollis (Wollaston): Beetle

California Pest Rating for
Dactylotrypes longicollis dorsal Collected off of Trithrinax brasiliensis (Image Citation: Steven Valley, Oregon Dept of Ag, Bugwood.org)
Dactylotrypes longicollis dorsal Collected off of Trithrinax brasiliensis
(Image Citation: Steven Valley, Oregon Dept of Ag, Bugwood.org)
Dactylotrypes longicollis (Wollaston): Beetle
Coleoptera: Curculionidae
Pest Rating:  C
PEST RATING PROFILE
Initiating Event:

On October 13, 2015 Dr. Andrew Cline identified two beetles collected from a Lindgren funnel trap as Dactylotrypes longicollis.  A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background:  Dactylotrypes longicollis feeds on the seeds of palms including wooly jelly palm (Butia eriospatha), Mediterranean fan palm (Chamaerops humilis), Canary Island date palm (Phoenix canariensis), date palm (Phoenix dactylifera), Senegal date palm (Phoenix reclinata), Brazilian needle palm (Trithrinax brasiliensis), and lady palm (Rhapis excelsa)1.  The beetle may be transported long distances when infested palm seeds or plants are moved.

Worldwide Distribution: Dactylotrypes longicollis is native to the Canary Islands and Madeira1.  From there it has spread to France, Italy, mainland Spain, and the Slovak Republic1.

Official Control: Dactylotrypes longicollis is not known to be under official control in any states or nations.  Dactylotrypes spp. are listed as harmful organisms by Peru2.

California Distribution:  Dactylotrypes longicollis has only been found in Fullerton (Orange County), San Marino (Los Angeles County), and Carpinteria (Santa Barbara County).

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

The risk Dactylotrypes longicollis would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: The known hosts and natural geographic range of Dactylotrypes longicollis indicate that the beetle is likely to be limited to southern California1.  It receives a Medium (2) 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: Dactylotrypes longicollis is only known to feed on the seeds of seven species of palms.  It receives a Low (1) 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: The biology of Dactylotrypes longicollis has not been well documented.  It is assumed to have a high reproductive rate and to be capable of dispersing long distances when infested palm fruit or plants are moved.  It 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 California date industry produces over 40 million pounds of dates annually and employees 2,500 people.  Dactylotrypes longicollis is not known to be established in major date producing nations and it is uncertain if the industry will be affected.  It is possible that the beetle could reduce crop yield or increase crop production costs.  The beetle is not expected to disrupt markets, change cultural practices, vector other organisms, injure animals, or disrupt water supplies.  It 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: In California Dactylotrypes longicollis is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It is not likely to affect threatened or endangered species or disrupt critical habitats.  It could trigger new treatment programs in the date industry.  It is not expected to impact cultural practices, home/urban gardening, or ornamental plantings.  Dactylotrypes longicollis receives a Medium (2) 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 Dactylotrypes longicollis: 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: Dactylotrypes longicollis is known to be established in Orange, Los Angeles, and Santa Barbara 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: Low (8)

Uncertainty:

We do not know how effective the Lindgren funnel is at detecting Dactylotrypes longicollis.  It is quite possible that the beetle is much more widespread in California.

Conclusion and Rating Justification:

Dactylotrypes longicollis has been established across much of southern California since before 2009.  No economic or environmental impacts have been attributed to the beetle.  A “C” rating is justified.

References:

1 LaBonte, James R. and Curtis Y. Takahashi. 2012. Dactylotrypes longicollis (Wollaston) (Coleoptera: Curculionidae: Scolytinae): an exotic bark beetle new to California and North America.  Pan-Pacific Entomologist. 88(2): 222-230 http://www.bioone.org/doi/abs/10.3956/2012-18.1

2 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:  C

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

Coleoptera, Insects, Mites & Earthworms

Pagiocerus frontalis (Fabricius): A Scolytid Weevil

California Pest Rating for
Pagiocerus frontalis (Fabricius): A Scolytid Weevil
Coleoptera: Cucurlionidae
Pest Rating: B
PEST RATING PROFILE
Initiating Event:

On May 21, 2014 Dr. Andrew Cline identified a beetle collected in Escondido, San Diego County, as Pagiocerus frontalis (PDR SJ0P06003026). This beetle was also reported from San Diego County in 2010. The beetle presently has a temporary rating of Q, so Dr. Kevin Hoffman recommended a pest rating proposal to determine future direction.

History & Status:

Background: Pagiocerus frontalis feeds and reproduces on the seeds of fallen avocado fruit and both fresh and dry corn. The species is considered a major pest of stored corn in the highlands of the Andes1,2. Beetles infest corn cobs in the field before harvest and continue feeding in storage, destroying the corn within several months1. The beetles have also been found on several other plants including coffee; however, a laboratory experiment found that these other plants were not suitable hosts for reproduction and development1. Pagiocerus frontalis is not known to have ever been intercepted, but could presumably spread long distances when infested fresh or dry corn or ripe, damaged avocados are moved.

Worldwide Distribution: Pagiocerus frontalis is a Neotropical beetle whose range extends from South America, through Central America and Mexico, into the southeastern United States.

Official Control: Pagiocerus frontalis is listed as a quarantine pest by Japan4 and New Zealand5.

California Distribution: In California Pagiocerus frontalis has only been found in San Diego County.

California Interceptions: Pagiocerus frontalis has never been intercepted in any regulatory situations in California.

The risk Pagiocerus frontalis would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Pagiocerus frontalis has a widespread distribution across a wide variety of climates from the Andes in South America to North Carolina. It can be expected to establish wherever it can find suitable host material in California. The beetle 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: Pagiocerus frontalis is only known to be able to complete its reproductive cycle on corn and the seeds of fallen avocados. It receives a Low (1) 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: Pagiocerus frontalis has high reproductive potential; females lay many eggs and it can complete its entire life cycle in 3 to 4 weeks1. The beetles may theoretically disperse long distances through the movement of infested corn or inside the seeds of ripe, damaged avocados. The beetle 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 value of corn produced in California was approximately $812.1 million in 2012. This includes $234.7 for grain, $454.4 for silage, and $123 million for sweet. Pagiocerus frontalis might increase production costs in these crops, especially organic sweet corn. The beetle is considered a quarantine pest by some nations. The beetle therefore has the potential to disrupt markets by contaminating corn or as a hitchhiker on other commodities. Pagiocerus frontalis 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: Pagiocerus frontalis is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. The beetle is not likely to directly affect threatened or endangered species or disrupt critical habitats. Large populations of the beetle might trigger new chemical treatments in corn when the crop is in the field or storage. Pagiocerus frontalis is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. The beetle receives a Medium (2) 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 Pagiocerus frontalis: 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: In California, Pagiocerus frontalis is only known to be established in San Diego County. The beetle 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.

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (10)

Uncertainty:

There are a wide variety of pests that feed on both fresh and dry corn. It is possible that existing treatments, cultural practices, and modified genes will preclude any economic damage from this pest in California.  Pagiocerus frontalis also feeds on the seed of fallen avocado. These avocados are not likely to be distributed commercially; nevertheless, the presence of this beetle might disrupt markets.

Conclusion and Rating Justification:

Pagiocerus frontalis is only known from San Diego County and has the potential to have limited economic and environmental impacts. A “B” rating is justified.

References:

1 Eidt-Wendt, J. and F.A. Schulz. Studies on the biology and ecology of Pagiocerus frontalis (Fabricius) (Coleoptera: Scolytidae) infesting stored maize in Ecuador. Technical University Berlin, Department of Phytomedicine, Berlin, FRG. http://spiru.cgahr.ksu.edu/proj/iwcspp/pdf2/5/61.pdf

2 Gianoli, E., I. Ramos, A. Alfaro-Tapia, Y. Valdéz, E.R. Echegaray, and E. Yábar. 2006. Benefits of a maize-bean-weeds mixed cropping system in Urubamba Valley, Peruvian Andes. International Journal of Pest Management. 52(4):283-289. http://www2.udec.cl/~egianoli/06gianintjpestman.pdf

4https://www.ippc.int/sites/default/files/documents/20130423/1309849796_qp_list_2013042321%3A18En.pdf

5 http://piorin.gov.pl/cms/upload/seed.pdf

Responsible Party:

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

 Pest Rating: B

Posted by ls