Pest Rating Proposals and Final Ratings

¹http://www.sel.barc.usda.gov/catalogs/diaspidi/Gymnaspisaechmeae.htm

Gymnaspis aechmeae Newstead: Fly Speck Scale

April 7, 2015 Jason Leathers

California Pest Rating for

Gymnaspis aechmeae Newstead: Fly Speck Scale

Hemiptera: Diaspididae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

On October 28, 2013 Dr. Gillian Watson identified fly speck scale, Gymnaspis aechmeae, from a sample of bromeliad plants submitted from a resident’s greenhouse in Orange County (PDR 300P06040190). Stephen Brown recommended that the scale be run through the draft pest rating process.

History & Status:

Background: Known colloquially in Australia as “the scourge of the bromeliads,⁴” fly speck scale is considered to be a serious pest of the plants^1,2,4,5,6. Known hosts include up to 35 species of Bromeliaceae: Acanthostachys sp., Acanthostachys strobilacea, Aechmea angustifolia, A. aquilega, A. bracteata⁷, Aechmea chantini, A. nidularioides, A. pubescens, Aechmea sp., Ananas comosus, A. sativus, Ananas sp., Aregelia sp., Billbergia nutans, B. leopoldi, B. pyramidalis⁷, B. saundersii, Billbergia sp, Bromelia serra, B.pinguin², Bromelia sp., Hogenbergia erythrostachya, H. stellata⁷, Hogenbergia sp., Karatas amazonica, Karatas sp., Neoregelia sp., Nidularium princeps, Nidularium sp., Pitcairnia sp., Quesnelia sp., Quesnelia wittmackiana, Tillandsia sp., Vriesea sp., Vriesia platzmanni. Other occasional hosts include Monstera sp. (Araceae), Asparagus sprengeri (Asparagaceae), Caraguata weilbachii and Chlorophytum sp. (Liliaceae), Villarsia officinalis (Menyanthaceae), and Cymbidium sp. (Orchidaceae)¹. Fly speck scale can be dispersed long distances in the trade of live plants.

Worldwide Distribution: The native range of fly speck scale is uncertain. It was first discovered on Aechmea aquilegia at Kew Gardens, London, in 1897¹. It was found in Spain by 1906¹, Argentina by 1907¹, and Florida in 1917⁵. It has since been found in Brazil, Costa Rica, Puerto Rico, Cuba², Hawaii, Japan³, Australia^4,6, and in many European nations¹. Within the United States it has also been found in additional eastern and southern states (Alabama, District of Columbia, Florida, Louisiana, Maryland, Missouri, New Jersey, New York, Pennsylvania and West Virginia) and Colorado⁸.

Official Control: Fly speck scale is listed as a quarantine pest in Japan and the Republic of Korea⁹.

California Distribution: Fly speck scale has never been found outdoors in California.

California Interceptions: Fly speck scale was found once in a nursery in San Diego county in 2012 (PDR 1422842).

The risk fly speck scale (Gymnaspis aechmeae) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Known outdoor habitats of fly speck scale correspond with tropical, humid environments. The scale is not likely to establish outdoors in California. However, bromeliads are produced and kept in greenhouses and the scale is likely to establish in these environments. Fly speck scale 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: Fly speck scale is primarily a pest of bromeliads, but it has been found on 41 species in 6 plant families. The scale receives a Medium(2) 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: Fly speck scale has only 2 generations per year¹, but can produce many first instar crawlers (rather than eggs) giving the species high reproductive potential. The crawlers are able to walk between plants⁶. Furthermore, they can be spread long distances when plants are traded, on clothing, or by wind⁶. Fly speck scale 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: Bromeliads are produced in the nursery industry of California. Fly speck scale is likely to lower the value of this crop by disfiguring the plants with their unsightly presence. The scale may also increase crop production costs as nurseries are likely to treat infestations or to treat preventively. Fly speck scale is listed as a quarantine pest by Japan and Korea⁹ so its presence in California could disrupt trade with those markets. Fly speck scale may also negatively change normal cultural practices in botanical gardens and nursery greenhouses. The scale is not expected to lower crop yield, trigger a loss of markets, vector other organisms, affect agriculturally important animals, or affect the water supply. Fly speck scale 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 o rganism.
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: The presence of Gymnaspis aechmeae can be expected to trigger regular, preventive private chemical treatment of bromeliads to prevent unsightly plants⁴and eradicate known infestations. Fly speck scale can also be expected to impact cultural practices in home/urban gardening as bromeliad collectors institute quarantine treatments as they acquire new plants⁴ and discard untreated, infested plants. The scale is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. No hosts of the scale are listed as threatened or endangered species in California and the scale is not expected to affect critical habitats. Fly speck scale 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 Fly Speck Scale (Gymnaspis aechmeae): Medium (12)**

–Low = 5-8 points
–Medium = 9-12 points
–High = 13-15 points

6) Post Entry Distribution and Survey Information: Fly speck scale is known only from a single incursion into California in a greenhouse in Orange County in 2013. It has not been found anywhere else since then. It receives a Not established(0) in this category.

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

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

Final Score:

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

Uncertainty:

Bromeliad enthusiasts may trade plants frequently and order plants from infested areas via the Internet and mail services; the scale could have a much wider distribution in California.

Conclusion and Rating Justification:

California’s climate is expected to limit the distribution of fly speck scale to greenhouse environments. There, the introduction of the scale is expected to have a significant economic impact by decreasing the value of contaminated bromeliads and increasing production costs. Fly speck scale is also expected to have a significant environmental impact as it can be expected to trigger additional private chemical treatments as residents attempt to both eradicate and prevent infestations. It will also alter cultural practices as residents will quarantine newly acquired plants and dispose of plants that become unsightly. A “B” rating is justified for Gymnaspis aechmeae.

References:

²Novoa, N.M., G.S. Hodges, M.V. Rubio, P.C. Bonnin, and P.H. Oliver. 2010. Nuevos registros de insectos escamas (Hemiptera: Sternorrhyncha: Coccoidea) para Cuba. Fitosanidad 14(3):181-183

³Mito, T. and T. Uesugi. 2004. Invasive alien species in Japan: the status quo and the new regulation for prevention of their adverse effects. Global Environmental Research 8(2): 171-191. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http%3A%2F%2Fwww.airies.or.jp%2Fattach.php%2F6a6f75726e616c5f30382d32656e67%2Fsave%2F0%2F0%2F08_2-08.pdf&ei=YN9vUtC9IsqDiQLx2IDACg&usg=AFQjCNF_T2F8hHiHRH1hX2i0gqYjsDcT1g&bvm=bv.55123115,d.cGE

⁴Bromelcairns. 2009 #2 and 2010#3. Bimonthly Newsletter of Cairns Bromeliad Society, Inc. P.O. Box 28 Cairns, Queensland, 4870 Australia. http://www.bromeliadsdownunder.com/wp-content/uploads/2012/03/Bromelcairns-2009-Issue-4.pdf

http://www.bromeliadsdownunder.com/wp-content/uploads/2012/02/Bromelcairns-2010-Issue-3.pdf

⁵Miller, D.R., G.L. Miller, G.S. Hodges, and J.A. Davidson. 2005. Introduced scale insects (Hemiptera: Coccoidea) of the United States and their impact on U.S. Agriculture. Proceedings of the Entomological Society of Washington 107(1): 123-158. http://www.sel.barc.usda.gov/coccoidea/millermihoda2005.pdf

⁶Illawarra Bromeliad Society Inc. Club News. October 2012. 92 Brighton Street, Bundeena, NSW 2230 http://www.bromeliad.org.au/news/Ill1012.htm

⁷Stephens, J.A. 1965. Some thoughts on bromeliads. The Bromeliad Society Bulletin. Vol. XV(5). http://journal.bsi.org/V15/5/

⁸http://www.forestryimages.org/browse/detail.cfm?imgnum=5117097

⁹ 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

¹http://www.xericworld.com/forums/showthread.php?t=2831

Paracoccus gillianae and Pseudococcus inconstans (formerly variabilis and sp. a): Agave Mealybugs

April 1, 2015 Jason Leathers

California Pest Rating for

Paracoccus gillianae and Pseudococcus inconstans (formerly variabilis and sp. A): Agave Mealybugs

Hemiptera: Pseudococcidae

Pest Rating: C

PEST RATING PROFILE

Initiating Event:

Two species of mealybugs have been found outdoors in California and are often found during nursery inspections of agave plants. The two insects, Paracoccus gillianae and the undescribed Pseudococcus sp. A (the A is for agave), are presently assigned a temporary rating of “Q”. A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background: Nothing is known of the biology of the agave mealybugs except that they appear to be mostly limited to agave in nurseries.

Worldwide Distribution: Unknown, possibly native to the southwestern United States or Mexico. The species appear to be moving about in the nursery trade. Specimens of Paracoccus gillianae have been collected in nurseries in seven counties in Florida and have been found outdoors at the Jacksonville Zoological Gardens in Duval County².

Official Control: The agave mealybugs are not known to be under official control anywhere in the world.

California Distribution: In California Pseudococcus sp. A was found outdoors in Los Angeles and Santa Barbara Counties in the 1980’s and 1990’s. It was found outdoors again in San Diego County in 2012 (PDRs 1326984 and 1401481). Paracoccus gillianae was found outdoors in Riverside County in 2012 (PDRs 1590291 and 1590292).

California Interceptions: Paracoccus gillianae and Pseudococcus sp. A have both been found in nurseries many times. USDA intercepted Paracoccus gillianae on plants from Mexico at Nogales in 1952 and San Diego in 1974. CDFA intercepted Paracoccus gillianae on plants that originated in Mexico in 2008 (PDR 1357956).

The risk agave mealybugs would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Agaves are popular in the nursery industry in California. Agave mealybugs are presumed likely to establish in residential areas where agaves are grown ornamentally and in desert ecosystems where native agaves grow. The agave mealybugs receive a Medium(2) rating for 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: The agave mealybugs appear to feed primarily on agave plants (Agave spp.). There are also records from other plants in the Agavaceae: Pseudococcus sp. A on aloe (PDR 1554869) and Paracoccus gillianae on Hesperaloe sp. and Yucca sp. The agave mealybugs receive a Low (1) rating for 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: Mealybugs can reproduce quickly but do not fly and therefore do not usually disperse far from their original host plant. However, mealybugs may be dispersed long distances by wind, by hitchhiking on animals or clothing, or by commerce in infested plants. The agave mealybugs receive a High (3) rating for 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 agave mealybugs have never been documented to cause economic damage anywhere, but dense infestations are unsightly and have been seen killing patches of leaf. Pseudococcus sp. A. has been found on the agave produced commercially for tequila production in Mexico. However, they are not documented as economic pests in their native range. Some nurseries are treating their agaves to prevent contamination by the mealybugs, increasing production costs. The agave mealybugs receive a Low (1) rating for 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: A widespread establishment of the agave mealybugs may result in increased pesticide use by nurseries and residents. Nurseries in Santa Barbara County have had difficulty in eradicating infestations using topical insecticide treatments resulting in repeated applications to get them under control. Other nurseries are using systemic insecticides to prevent the mealybugs from showing up on their agaves¹. Therefore, if the rating were changed for the agave mealybugs it is expected to reduce pesticide use. There are no plants in the genera Agave, Aloe, Hesperaloe, or Yucca listed as threatened or endangered plants in California. There are no reports of agave mealybugs causing environmental damage anywhere in the world. The agave mealybugs receive a Low (1) rating for 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 Agave Mealybugs: Low (8)

Add up the total score and include it here.

-Low = 5-8 points
-Medium = 9-12 points
-High = 13-15 points

6) Post Entry Distribution and Survey Information: Agave mealybugs have been found in the environment of Los Angeles and Santa Barbara Counties. They receive 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: Low (7)

Uncertainty:

It is possible that the agave mealybugs could have a wider host range than is known, resulting in greater consequences from establishment. It is also likely that the mealybugs have spread to other states where Agavaceae grow.

Conclusion and Rating Justification:

The agave mealybugs Paracoccus gillianae and Pseudococcus sp. A have been found outdoors in California and appear to be established in the nursery system. They do not appear to be causing any economic damage (other than through their quarantine status). They are not expected to have significant environmental impacts to California. A C-rating is justified for these pests.

References:

²Von Ellenrieder, Natalia and Ian C. Stocks. 2014. A new species of mealybug in the genus Paracoccus Ezzat & McConnell from North America (Insecta: Coccoidea: Pseudococcidae). Zootaxa 3873(1):025-036.

Responsible Party:

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

Pest Rating: C

Posted by ls

Unaspis citri Comstock: Citrus Snow Scale

California Pest Rating for

Unaspis citri Comstock: Citrus Snow Scale

Hemiptera: Diaspididae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

Unaspis citri is frequently intercepted by CDFA and requires a pest rating proposal to support its pest rating.

History & Status:

Background: Unaspis citri, citrus snow scale, is an armored scale insect that primarily feeds on the trunk and tree limbs of older citrus trees¹. Populations of the scale reduce tree vigor and fruit production¹. Prolonged high populations can cause bark to split, allowing other insect pests and pathogens to invade the tree¹. Known hosts of citrus snow scale include: Anacardiaceae: mango (Mangifera indica³), Mangifera sp.²,³; Annonaceae: custard apple (Annona muricata²,³); Arecaceae: Cocos sp.²,³; Bromeliaceae: Ananas sp.²,³, Spanish moss (Tillandsia usneoides²,³); Celastraceae: evergreen spindle (Euonymus japonicus²,³), broad-leaved spindle tree (Euonymus latifolia²,³), Fabaceae: Acacia sp.²,³, Inga sp.³; Malvaceae: Hibiscus sp.²,³; Musaceae: Musa sp.²,³; Myrtaceae: guava (Psidium guajava²,³); Oleaceae: Osmanthus sp.²,³; Pittosporaceae: Pittosporum sp.²,³; Rosaceae: avocado (Persea americana²,³); Rutaceae: Mediterranean mandarin (Citrus deliciosa²,³), Citrus sp.²,³, key lime (Citrus aurantifolia²,³), bitter orange (Citrus aurantium²,³), Citrus decumana²,³, sweet orange (Citrus sinensis²,³), mandarin (Citrus reticulata²,³), grapefruit (Citrus paradisi²,³), tangerine (Citrus nobilis²,³), citron (Citrus medica²,³), Citrus medica acida², pomelo (Citrus maxima²,³), lemon (Citrus limon²,³), Citrus grandis²,³, kumquats (Fortunella sp.²,³), Glycosmis parviflora²,³, orange jessamine (Murraya paniculata²,³), trifoliate orange (Poncirus sp.²,³), Severina sp.²,³; Sapindaceae: rambutan (Nephelium lappaceum²). Unaspis citri may be transported long distances when infested plants or fresh plant parts are moved.

Worldwide Distribution: Unaspis citri is believed to have originated in Asia, but has spread through many of the citrus growing regions of the world¹.

Official Control: Unaspis citri has listed as a harmful organism by 46 nations including Albania, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Holy See (Vatican City State), Hungary, India, Ireland, Israel, Italy, Japan, Jordan, Korea, Latvia, Lithuania, Luxembourg, Malta, Monaco, Montenegro, Morocco, Netherlands, New Zealand, Poland, Portugal, Romania, San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Taiwan, Turkey, United Kingdom, Venezuela⁴.

California Distribution: Unaspis citri has never been found in the environment of California.

California Interceptions: Unaspis citri is commonly intercepted by CDFA’s border stations on citrus fruit from Mexico and Florida.

The risk Unaspis citri (citrus snow scale) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Citrus is widely planted across much of California and Unaspis citri can be expected to establish wherever it is grown. It receives a High (3) in this category.

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

2) Known Pest Host Range: Unaspis citri is known to feed on 34 varieties of plants in 13 families. It receives a Medium (2) 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: Scale insects are capable of rapid reproduction and can be transported long distances when infested plants or fresh plant parts are moved. They may also disperse locally by crawling, wind, or by hitchhiking on clothing, equipment, or animals. Unaspis citri 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: If Unaspis citri were to establish in California it is expected that it would lower yields and increase crop production costs in citrus nursery stock and fruit industries. Citrus snow scale is also considered a quarantine pest by many of California’s trading partners. The presence of the scale in the state would disrupt markets for fresh fruit and nursery stock. Unaspis citri 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: Unaspis citri is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It is not expected to directly affect threatened or endangered species or disrupt critical habitats. It may trigger additional treatment programs in agriculture and by residents who find infested trees unsightly or diminished citrus yields unacceptable. Citrus snow scale may also significantly impact ornamental plantings. It 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 Unaspis citri (Citrus Snow Scale): High (14)

Add up the total score and include it here.

– Low = 5-8 points
– Medium = 9-12 points
– High = 13-15 points

6) Post Entry Distribution and Survey Information: Unaspis citri has never been found in California and receives a Not established (0) in this category.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (14)

Uncertainty:

Management for other citrus pests may mitigate some of the damage from Unaspis citri.

Conclusion and Rating Justification:

Unaspis citri has never been found in California and it is expected to have significant economic and environmental impacts if it were to enter the state. An “A” rating is justified.

References:

¹ Buckley, Courtney R. and Amanda C. Hodges. 2013. University of Florida Featured Creatures: Common Name: citrus snow scale. http://entnemdept.ufl.edu/creatures/orn/scales/citrus_snow_scale.htm

² Miller, Dug, Yair Ben-Dov, Gary Gibson, and Nate Hardy. ScaleNet. http://scalenet.info/validname/Unaspis/citri/

³ SEL Catalog. http://www.sel.barc.usda.gov/catalogs/diaspidi/Unaspiscitri.htm

⁴ 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: A

Posted by ls

Insects, Mites & Earthworms, Thysanoptera

Thrips palmi (Karny): Melon Thrips

California Pest Rating for

Thrips palmi (Karny): Melon Thrips

Thysanoptera: Thripidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

March 5, 2015 the United States Department of Agriculture announced that it is considering a change in the status of Thrips palmi, melon thrips, to non-actionable and may therefore stop taking action on the pest when it is intercepted at U.S. ports¹. A pest rating proposal is required to determine a permanent pest rating.

History & Status:

Background: Thrips palmi is a highly polyphagous insect that breeds on the flowers, stems, leaves and fruit of many species of plants and causes serious damage to food crops²,⁴. Crops that are often severely damaged include: Solanaceae: eggplant (Solanum melongena⁴), pepper (Capsicum spp.⁴), potato (Solanum tuberosum⁴), tobacco (Nicotiana tabacum⁴), ground cherry (Physalis spp.⁴); Cucurbitaceae: bittermelon (Momordica charantia⁴), cucumber (Cucumis sativus⁴), watermelon (Citrullus lanatus⁴), muskmelon (Cucumis melo⁴), cantaloupe (Cucumis melo subsp. melo⁴), pumpkin (Cucurbita pepo⁴), squash (Cucurbita spp.⁴), zucchini (Cucurbita pepo⁴), edible gourds (Cucurbita spp.⁴); hyotan (Lagenaria siceraria⁴); Leguminosae: kidney bean (Phaseolus vulgaris⁴), broad bean (Vicia faba⁴), cowpea (Vigna unguiculata⁴), green bean (Phaseolus vulgaris⁴), soybean (Glycine max⁴), togan (Benincasa hispida⁴); Amaranthaceae: chinese spinach and amaranth spinach (Amaranthus dubius⁴); Benincaseae: Chinese wax gourd (Benincasa hispida⁴); Asteraceae: Chrysanthemum spp.⁴, Dahlia spp.⁴; Malvaceae: cotton (Gossypium spp.⁴); Myrsinaceae: Cyclamen spp.⁴; Convolvulaceae: morning glory⁴, sweet potato (Ipomoea batatas⁴); Orchidaceae: orchids⁴; Apocynaceae: Plumeria spp.⁴; Pedaliaceae: sesame (Sesamum indicum⁴). Other reported hosts include: Lauraceae: avocado (Persea americana⁵); Rutaceae: Citrus spp.⁵; Anacardiaceae: mango (Mangifera indica⁵); Rosaceae: peach (Prunus persica⁵), plum (Prunus spp.⁵). Thrips palmi may be transported long distances when infested nursery stock or fresh plant parts are moved.

Worldwide Distribution: Thrips palmi is native to South-East Asia and has spread to many tropical locations throughout the world². It is established in Hawaii and Florida.

Official Control: Thrips palmi is listed as a harmful organism by 73 nations including: Albania, Antigua and Barbuda, Argentina, Armenia, Austria, Azerbaijan, Belarus, Belgium, Bermuda, Brazil, Bulgaria, Chile, Colombia, Costa Rica, Croatia, Cuba, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, French Polynesia, Georgia, Germany, Greece, Guatemala, Holy See (Vatican City State), Honduras, Hungary, Iceland, Ireland, Israel, Italy, Jamaica, Japan, Kazakhstan, Latvia, Lithuania, Luxembourg, Malta, Mexico, Moldova, Republic of Monaco, Montenegro, Morocco, Netherlands, New Zealand, Norway, Panama, Paraguay, Peru, Poland, Portugal, Romania, Russian Federation, San Marino, Serbia, Slovakia, Slovenia, South Africa, Spain, Svalbard and Jan Mayen, Sweden, Switzerland, Tajikistan, Tunisia, Turkey, Turkmenistan, Ukraine, United Kingdom, Uruguay, and Uzbekistan³.

California Distribution: Thrips palmi has never been found in the environment of California.

California Interceptions: CDFA’s high risk programs, dog teams, and border stations have intercepted Thrips palmi 64 times on consignments from Hawaii and Florida. Most interceptions have been on orchids imported from Hawaii.

The risk Thrips palmi (melon thrips) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Thrips palmi is polyphagous and suitable hosts are grown throughout the state. However, melon thrips is only known to be established in tropical climates and greenhouses; some of the colder parts of California may be unsuitable for establishment. Thrips palmi receives a Medium (2) in this category.

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

2) Known Pest Host Range: Thrips palmi feeds on more than 50 species of plants in at least 20 families. It receives a High (3) in this category.

Evaluate the host range of the pest. Score:

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

3) Pest Dispersal Potential: Under favorable conditions, Thrips palmi can complete a generation in less than two weeks and each female can lay 100-200+ eggs. This indicates a high reproductive rate. Thrips palmi are small and are frequently hidden in pockets, cracks, and crevices on host material⁴. This enables them to elude inspections and facilities long distance dispersal through the movement of infested consignments. Thrips palmi receives a High (3) in this category.

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

4) Economic Impact: Thrips palmi is a primary pest of some crops and can be expected to reduce crop yields and increase crop production costs if it were to establish in California. The species is of quarantine significance to at least 73 nations and can be expected to disrupt markets for Californian agricultural commodities. Thrips palmi is also known to be an efficient vector of multiple plant pathogens including tomato spotted wilt virus⁵, bud necrosis virus⁵, and at least two other plant pathogens². Melon thrips receives a High (3) in this category.

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

– 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 Thrips palmi were to establish in California it could be expected to trigger additional treatment programs at farms, orchards, nurseries, and by residents. Melon thrips would also have significant impacts to home/urban gardening and ornamental plantings. Thrips palmi 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 Thrips palmi (Melon Thrips): High (14)

Add up the total score and include it here.

– Low = 5-8 points
– Medium = 9-12 points
– High = 13-15 points

6) Post Entry Distribution and Survey Information: Thrips palmi has never been found in California and receives a Not established (0) in this category.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (14)

Uncertainty:

The climate of California may be less suitable to the establishment of Thrips palmi.

Conclusion and Rating Justification:

Thrips palmi has not been found in California and would have significant economic and environmental impacts if it were to enter the state. An “A” rating is justified.

References:

¹ USDA Pests No Longer Regulated at U.S. Ports of Entry. http://www.aphis.usda.gov/wps/portal/aphis/ourfocus/planthealth/sa_domestic_pests_and_diseases/sa_frsmp?1dmy&urile=wcm%3apath%3a%2Faphis_content_library%2Fsa_our_focus%2Fsa_plant_health%2Fsa_domestic_pests_and_diseases%2Fsa_frsmp%2Fct_non-reg-pests

² Hoddle, M.S., Mound, L.A., Paris, D.L. 2012. Thrips of California. CBIT Publishing, Queensland. http://keys.lucidcentral.org/keys/v3/thrips_of_california/identify-thrips/key/california-thysanoptera-2012/Media/Html/browse_species/Thrips_palmi.htm

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

⁴ University of Hawaii Crop Knowledge Master: Thrips palmi (Karny). http://www.extento.hawaii.edu/kbase/crop/type/t_palmi.htm

⁵ Capinera, J.L. 2013. University of Florida Featured Creatures: Common Name: Melon Thrips. http://entnemdept.ufl.edu/creatures/veg/melon_thrips.htm

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

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:

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:

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.

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

Diptera, Insects, Mites & Earthworms

Eumerus figurans (Walker): Ginger Maggot

California Pest Rating for

Eumerus figurans (Walker): Ginger Maggot

Diptera: Syrphidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

Eumerus figurans is occasionally intercepted by CDFA’s high risk programs and is presently assigned a temporary rating of “Q”. A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background: Eumerus figurans is a syrphid fly whose larvae feed on various bulbs, corm, and roots¹. Female flies are attracted to and lay eggs on injured and rotting bulbs, corms and roots^1,2. Larvae are gregarious and hollow out bulbs as they feed². Damage by the larvae is considered secondary to bacterial and fungal rot organisms¹. Known hosts include ginger roots, lily bulbs, narcissus bulbs, decomposing pineapple stumps, and rotting dry land taro¹. Larvae of Eumerus figurans may be transported long distances when infested ginger roots or other plant parts are moved.

Worldwide Distribution: The native range of Eumerus figurans is probably the tropical forests of South-east Asia. Walker described the species from Celebes and there are undescribed sibling species present in Thailand, suggesting an evolutionary origin in that region. Eumerus figurans has spread throughout much of Asia and the Southwest Pacific¹. It was first found in Hawaii in 1902¹.

Official Control: Eumerus figurans itself is not known to be under official control by any other states or nations³. However, all members of the genus Eumerus are considered harmful organisms by Bermuda³, Iceland³, and Japan³.

California Distribution: Eumerus figurans has never been found in the environment of California.

California Interceptions: Between January 1, 2000 and December 31, 2014 Eumerus figurans was intercepted 20 times by CDFA’s high risk programs. All interceptions for which data were recorded were on shipments of ginger root from Hawaii.

The risk Eumerus figurans (ginger maggot) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Ginger grows as a perennial plant in USDA zones 9 through 12. This corresponds with much of California. Eumerus figurans is likely capable of finding injured ginger roots to feed on throughout this area. However, the fly is typically found in humid tropical and subtropical environments. Ginger maggot receives a Medium (2) in this category.

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

2) Known Pest Host Range: Eumerus figurans is known to feed on injured ginger roots, lily bulbs, narcissus bulbs, decomposing pineapple stumps, and rotting dry land taro1. 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: Species of Eumerus are thought to have 3 generations per year in Israel³. Since California also has a Mediterranean climate Eumerus figurans is likely to have 3 generations per year here. Female flies lay eggs in groups of 10-20 per bulb³, giving them a high reproductive rate. The flies may be transported long distance through the movement of infested plants or plant parts. Eumerus figurans receives a High (3) in this category.

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

4) Economic Impact: Eumerus figurans is considered a secondary pest of ginger and there appears to be more literature published on the fly’s role as a pollinator than a pest. It is not expected to lower any crop yields in California. Ginger maggot is likely to be considered a quarantine pest by Iceland³, Bermuda³, and Japan³ and has the potential to disrupt exports of ginger, lily, or narcissus bulbs to those markets. However, Eumerus figurans is unlikely to establish in Iceland and is already present on Nansei Island in Japan. Lost markets may therefore be limited to exports of ginger, lily, and narcissus bulbs to Bermuda. The fly may also increase crop production costs if growers manage populations of the flies. Eumerus figurans is not expected to negatively change normal cultural practices, vector pestiferous organisms, injure animals, or interfere with 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: If Eumerus figurans were to enter California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. Ginger maggot is not expected to directly affect threatened or endangered species or disrupt critical habitats. It is possible that the flies could trigger new treatment programs in the nursery industry, ginger gardens, or by residents who consider flies a nuisance. Ginger maggot is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. Eumerus figurans 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 Eumerus figurans (Ginger Maggot): 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: Eumerus figurans has never been found in the environment in California and receives a Not established (0) in this category.

Final Score:

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

Uncertainty:

There is some speculation that Eumerus figurans might play a role in the spread of bacterial and fungal rot organisms between ginger plants¹. If confirmed, this could increase its economic impact.

Conclusion and Rating Justification:

Eumerus figurans (ginger maggot) has never been found in California. It is expected to have limited economic and environmental impacts if it were to enter the state. A “B” rating is justified.

References:

¹ Mau, R.F.L., J.L. Martin Kessing. 1992. Eumerus figurans (Walker). Hawaii Crop Knowledge Master. http://www.extento.hawaii.edu/kbase/crop/type/eumerus.htm

² Hill, Dennis S. 1987. Agricultural Insect Pests of Temperate Regions and Their Control. CUP Archive. 659pp. https://books.google.com/books?id=3-w8AAAAIAAJ&dq=eumerus+figurans+ginger&source=gbs_navlinks_s

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

Diptera, Insects, Mites & Earthworms

Dasineura mali (Kieffer): Apple Leaf Gall Midge

California Pest Rating for

Dasineura mali (Kieffer): Apple Leaf Gall Midge

Diptera: Cecidomyiidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

In August 2014 USDA released a draft pest list for apples and pears from the European Union. Dasineura mali, which is present in Europe, is not on this list. Because the fly presently has a temporary rating of “Q” a pest rating proposal is needed to determine future direction.

History & Status:

Background: Dasineura mali is a small fly that feeds only on species of apples. Adult females lay eggs in leaf folds of immature apple leaves¹. After eggs hatch, larval feeding causes the margins of leaves to curl¹. Curled leaves become brittle and may fall from the tree¹. Heavy infestations may reduce shoot growth, reducing photosynthetic leaf area⁵. This may stunt growth of nursery stock and newly planted trees. Larvae of the midge sometimes pupate in the calyx of fruit. They can therefore spread long distances by the movement of infested fruit, trees, or other apple plant material.

Worldwide Distribution: Dasineura mali is native to Europe¹. It has spread to New Zealand, Argentina, and Canada². In the United States it has been present in New York and Massachusetts since the 1960’s and was found in Washington State in 1994¹. The midge has since spread through much of western Washington, but it is not known if it occurs in the major apple production areas east of the Cascades.

Official Control: Dasineura mali is listed as a quarantine pest by China, Taiwan, Japan, Republic of Korea, and Peru³.

California Distribution: Dasineura mali has never been found in the environment of California.

California Interceptions: Dasineura mali has been intercepted by CDFA’s border stations 89 times since 2000, typically as pupae on apple fruit from New Zealand or the Pacific Northwest.

The risk Dasineura mali (apple leaf gall midge) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Apple trees are commonly grown as ornamentals throughout California and apples are produced commercially in nearly every county in the state⁴. Dasineura mali is likely to establish wherever apples are grown and 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: Dasineura mali is only known to feed on species of apple (Malus spp.). 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: Dasineura mali has high reproductive potential. There are 2-4 generations per year^{1, 5}, and each female lays many eggs. Although midges are not strong fliers, they may be spread long distances by wind or commerce in infested fruit or plants. Dasineura mali receives a High (3) in this category.

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

4) Economic Impact: California is the 2nd largest exporter of apples in the United States and the 5th largest producer⁴. California growers ship apples to 27 countries⁴. 14,000 acres are dedicated to apple production and yield a crop valued at over $105,000,0004. If Dasineura mali were to enter California it is probable that it would disrupt export markets due to its habit of pupating in the fruit calyx. It is also likely to increase production costs by triggering new chemical treatments since biological control is often not effective in commercial apple orchards due to the use of broad spectrum insecticides targeting other pests⁵. Dasineura mali larvae are protected from such applications inside leaf curls⁵. Fruit yield of mature orchards is usually not reduced by this midge, but they may sometimes have reduced fruit size and fruit bud formation⁵. Newly planted trees and nursery stock are vulnerable to reduced shoot growth⁵. Dasineura mali 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: Dasineura mali is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It is not expected to directly affect threatened or endangered species or disrupt critical habitat. The midge may trigger additional treatment programs in nurseries, orchards, and residential settings. Apple trees are popular ornamentals and may be disfigured by the presence of this midge. Dasineura mali receives a High (3) in this category.

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

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 Dasineura mali (Apple Leaf Gall Midge): High (13)

Add up the total score and include it here.

– Low = 5-8 points
– Medium = 9-12 points
– High = 13-15 points

6) Post Entry Distribution and Survey Information: Dasineura mali has never been found in the environment of California and receives a Not established (0) in this category.

Final Score:

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

Uncertainty:

Dasineura mali was accidentally introduced into New Zealand in 1950 and was fortuitously controlled in orchards by existing treatments⁶. However, by the mid 1980’s midge populations and damage increased considerably to the point where new chemical treatments were required⁶. It is possible that damage to orchards in California will be limited until the species adapts to current integrated pest management practices.

Conclusion and Rating Justification:

Dasineura mali has never been found in California. Its entry to the state may have significant economic and environmental impacts to California’s apple industry and ornamental apple trees. An “A” rating is justified.

References:

¹Antonelli, Art and Jenny Glass. 2005. Apple Leaf Curling Midge. WSU Puyallup Plant & Insect Diagnostic Laboratory. http://puyallup.wsu.edu/plantclinic/resources/pdf/pls18appleleafcurlingmidge.pdf

²CAB Direct. Distribution Maps of Plant Pests 2008. http://cabdirect.org/abstracts/20083279226.html;jsessionid=39C077A8B4AABFDE351642AF7450D0FD

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

⁴California Apple Commission website. http://www.calapple.org/faq.php?n=14&id=7#q3

⁵Apple Best Practice Guide, Department for Environment Food and Rural Affairs, UK. Horticultural Development Company. http://apples.hdc.org.uk/apple-leaf-midge.asp

⁶Tomkins, A.R., D.J. Wilson, C. Thomson, S. Bradley, L. Cole, P. Shaw, A. Gibb, D.M. Suckling, R. Marshall, and C.H. Wearing. 2000. Emergence of apple leafcurling midge (Dasineura mali) and its parasitoid (Platygaster demades). New Zealand Plant Protection 53:179-184.

Responsible Party:

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

Pest Rating: A

Posted by ls

Delottococcus confusus (De Lotto): A Protea Mealybug

California Pest Rating for

Delottococcus confusus (De Lotto): A Protea Mealybug

Hemiptera: Pseudococcidae

Pest Rating: C

PEST RATING PROFILE

Initiating Event:

In association with a nursery regulatory inspection on November 20, 2012, San Luis Obispo County inspectors collected a sample of mealybugs from Protea trees in a residential neighborhood. On November 21, Dr. Natalia von Ellenrieder (CDFA) identified these mealybugs as Delottococcus confusus DeLotto (PDR 1599182). This was the first time this species was found in an outdoor situation in California not on nursery stock.

History & Status:

Background: Delottococcus confusus is primarily known as a pest of Proteaceae (Protea sp., P. caffra, P. cynarioides, Leucadendron sp. and Leucadendron argenteum). Other host records include Brunia and Berzelia lanuginose (Bruniaceae) (PDR 1267226), Canthium subovatum (Rubiaceae), Carissa sp. (Apocynaceae), Lycium sp. and Lycium tetrandrum (Solanaceae), Mimusops sp. and Mimusops caffra (Sapotaceae), Plectranthus sp. (Lamiaceae), Psidium guajava (Myrtaceae), Trichilia sp. and Trichilia emetica (Meliaceae), and Xymalos monospora (Monimiaceae)¹. Because the host plants (Proteaceae) are commonly grown for both cut flowers and landscape plants, Delottococcus confusus may be spread through international plant trade.

Worldwide Distribution: Delottococcus confusus is native to South Africa². The only other locality where the mealybug is known to be present is Hawaii¹. Records from Portugal³ may be based on a species misidentification.

Official Control: Delottococcus confusus is not known to be under official control anywhere.

California Distribution: Delottococcus confusus was first found in the environment in November 2012 on protea trees in a residential neighborhood of Los Osos, San Luis Obispo County. Follow-up surveys for the mealybug found it in neighboring Morro Bay (PDRs FR0P06009404 and FR0P06009408) and Escondido, San Diego County (PDR SD0P06153483).

California Interceptions: Delottococcus confusus was first found on cut protea flowers that originated from a nursery in San Diego County in April 2003 (PDR 1254887). In December 2003 the mealybugs were found on protea plants in a nursery in Monterey County (PDR 1402552). In 2004 they were next found on protea plants and Berzelia lanuginose in two nurseries in Ventura County (PDRs 1267227, 1267226, 1267251, 1267252, 1267253) as well as protea plants in a nursery in San Luis Obispo County (PDRs 1334145, 1334146, 1334147, 1334148, 1334139, 1334401, 1334992, 1334993 1334998, 1334999, 1335000). In 2005 the mealybug was found on protea plants in a nursery in Santa Cruz County (PDR 1289989) and on cut protea flowers that originated from a second nursery in San Diego County (PDR 1367761). Then in November 2006 a heavy infestation of the mealybug was found outdoors on Leucadendron argenteum trees and to a lesser extent other protea at a nursery in Sonoma County⁴ (PDRs 1428445, 1428417). In 2007 CDFA began to intercept the mealybugs on shipments of cut flowers and foliage from Hawaii (PDRs 1423774, 1354945, 1556872, 1556886, 1494189, 1649533, 1509569, 1544327, 1649626, 1555754, 1555768, 1631162, 300P06039982, 300P06039987, 1544072, 1544071, 1609382, 300P06040043, 450P06001871, 1641489, 190P06058445, 300P06040121). In 2008 Delottococcus confusus resurfaced on protea plants at the same nursery in San Luis Obispo County (PDRs 1458700, 1458708). In 2009 they were found on protea plants in a greenhouse and outside at a second nursery in San Luis Obispo County (PDRs 1459343, 1335105 ) as well as at a nursery in Santa Barbara County (PDR 1555084). In 2010 they were intercepted on protea plants from a 2^nd nursery in Santa Barbara County (PDR 1645051), and in 2011 they were found on protea plants at a repeat nursery (PDR 1554851) and a new nursery (PDR 1658335) in Santa Barbara County. In 2012 they were found on protea plants at a nursery in Riverside County (PDR 1590378) and intercepted on a shipment of cut flowers from a nursery in Santa Barbara County (PDR 1576404). And in November 2012 they were found in a repeat nursery in San Luis Obispo County where they were found in 2009 (PDR 1599179), as well as in a residential neighborhood near that nursery (PDR 1599182).

The risk Delottococcus confusus poses to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Proteaceae are commonly grown as ornamental plants in California and are common in the nursery industry. Delottococcus confusus is expected to be able to establish wherever these plants are grown. D. confusus receives a High (3) rating 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) Pest Host Range: All of the Delottococcus confusus collected in the United States to date have been on Proteaceae except for one record on Berzelia lanuginose (Bruniaceae). However, there are records of the mealybug from South Africa, verified by a taxonomic expert, on a variety of other hosts in eight other plant families¹. D. confusus receives a Medium (2) in this category.

Evaluate the host range of the pest:

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

3) Pest Dispersal Potential: Delottococcus confusus has demonstrated its ability to disperse long distances through the trade of ornamental plants and flowers. Mealybugs may also be dispersed by wind. They are capable of rapid reproduction and large infestations of the mealybug have appeared relatively rapidly in California⁴. D. confusus receives a High (3) in this category.

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

4) Economic Impact: Heavy infestations of Delottococcus confusus are capable of damaging nursery stock by causing necrosis of leaves and growing tips and may kill trees⁴. The mealybug may also cause significant problems for proteas grown for cut flowers4 by contaminating flowers by their presence, honeydew, and sooty mold⁵. Cut flowers are a $477 million industry in California and other states and nations may reject infested flowers. Furthermore, D. confusus has been recorded from guava (Psidium guajava)¹. Guava is a very popular tree in the Southern California landscape and there is at least some commercial guava production in California that may be affected. D. confusus could trigger a loss of markets and may increase production costs of nursery stock and cut flowers. The mealybug receives a Medium (2) rating in this category.

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

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

5) Environmental Impact: There are no plants listed as threatened or endangered in California that are expected to be hosts of Delottococcus confusus. Populations of the mealybug have been found established in residential areas and outdoor nursery settings and do not appear to be triggering any additional treatment programs by residents or industry. Furthermore there is no evidence that any residents are replacing infested plants with alternative species. Protea plants supporting populations of D. confusus are still alive in an abandoned nursery setting in San Diego County, suggesting that unmanaged populations of D. confusus may not kill plants. D. confusus receives a Low (1) rating 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 Delottococcus confusus: 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: Delottococcus confusus has been found to be established by survey in San Luis Obispo County and San Diego County. The mealybug receives a High (-3) in this category.

Evaluate the known distribution of pest in California. Only official records and published records identified by a taxonomic expert and backed up 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 1 California ecoarea
(region)
– Medium (-2) Pest is widespread in California but has not fully established in the endangered area; or pest established in 2 contiguous ecoareas
– High (-3) Pest has fully established in the endangered area; or pest reported in more than 2 contiguous or non-contiguous ecoareas

Consequences of Introduction to California for Delottococcus confusus: Low (8)

Add up the total score and include it here.

– Low = 5-8 points
– Medium = 9-12 points
– High = 13-17 points

Uncertainty:

Outside of the areas where Delottococcus confusus has been found in the environment, populations of the mealybug have been found in outdoor situations in other nurseries at distant locations, sometimes in large populations. It is probable that the mealybug has escaped into the environment from some of these nurseries or other undetected, similar situations. The mealybug may have a larger distribution in the state than is realized.

Under some circumstances, heavy infestations of the pest might trigger additional treatment programs in the nursery industry or by residents who find infested ornamental plants unacceptable. The mealybug could also cause minor alteration of urban landscaping as some residents and landscapers may replace infested plants with alternative species. This could lead to a moderate, albeit localized, environmental impact in some cases.

Conclusion and Rating Justification:

Delottococcus confusus has been appearing in California’s nursery system for a decade. Surveys have now revealed that the pest is established in San Luis Obispo County and San Diego County. There is no evidence that the mealybug is significantly impacting the environment or economy. The mealybug is probably present in other parts of California and is expected to establish a widespread distribution in the state. The Low (8) consequences of the mealybug in California justify an C rating.

References:

¹Miller, D.R. and J.H. Giliomee. 2011. Systematic revision of the mealybug genus Delottococcus Cox & Ben-Dov (Hemiptera: Pseudococcidae). African Entomology 19(3): 614–640. http://www.sel.barc.usda.gov/Coccoidea/Delottococcus.pdf

²Lotto, G. De. 1977. On some African mealybugs (Homoptera: Coccoidea: Pseudococcidae). Journal of the Entomological Society of Southern Africa. 40(1):13-36. http://www.cabdirect.org/abstracts/19770546873.html

³Leandro, M.J., Oliveira, M., Passarinho, A.M., Figueiredo, E., Franco, J.C., Neves-Martins, J. and Mexia, A. 2008. ASSESSMENT OF PARASITISM BY ANAGYRUS PSEUDOCOCCI AND LEPTOMASTIX DACTYLOPII ON MEALYBUGS FROM PROTEACEAE. Acta Hort. (ISHS) 805:121-126 http://www.actahort.org/books/805/805_14.htm

⁴Watson, Gillian. 2006. HEMIPTERA: STERNORRHYNCHA: NEW FEDERAL RECORDS. California Plant Pest and Disease Report 23(1):10. http://www.cdfa.ca.gov/plant/ppd/PDF/CPPDR_2006_23-1.pdf

⁵Mazzeo, G., J.C. Franco, and A. Russo. 2009. A new Paracoccus species from Palaearctic region (Hemiptera, Sternorrhyncha, Coccoidea, Pseudococcidae) . Zootaxa 2274: 62–68 http://www.mapress.com/zootaxa/2009/f/zt02274p068.pdf

⁶Sasa, A. 2011. Arthropods associated with commercial Proteaceae in the Western Cape Province, South Africa. http://scholar.sun.ac.za/handle/10019.1/6805

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

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.

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.

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.

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

Paracoccus hakeae Williams: A Protea Mealybug – SYNONYM: Phenacoccus hakeae

¹http://www.sel.barc.usda.gov/catalogs/pseudoco/Phenacoccushakeae.htm

California Pest Rating for

Paracoccus hakeae Williams: A Protea Mealybug

Synonym: Phenacoccus hakeae

Hemiptera: Pseudococcidae

Pest Rating: C

PEST RATING PROFILE

Initiating Event:

In March 2013, a visual delimitation survey was conducted in a 400m radius in Los Osos (San Luis Obispo County) following the first detection of the mealybug Delottococcus confusus in California. Mealybugs collected on 10 residential properties during this survey were identified as Phenacoccus hakeae by Drs. Gillian Watson and Natalia von Ellenrieder on March 29, 2012, a new continental record.

History & Status:

Background: Phenacoccus hakeae was described from specimens collected on Hakea sericea (Proteaceae) in New South Wales, Australia¹. It has also been intercepted by USDA-APHIS on cut flowers (Persoonia sp., Leucospermum sp., and other Proteaceae) imported from Australia and also on cut flowers (presumably Proteaceae) in shipments from the Netherlands². In San Luis Obispo County, the mealybugs have been collected on Leucadendron sp. (PDRs FR0P06009425, FR0P06009426, and FR0P06009430), Protea sp. (PDRs FR0P06009383, FR0P06009384, FR0P06009386, FR0P06009387, FR0P06009389, FR0P06009400, FR0P06009401, FR0P06009421, FR0P06009423, FR0P06009427, FR0P06009429, FR0P06009431, FR0P06009433, and FR0P06009434), and Grevillea sp. (PDR FR0P06009428). Because the host plants (Proteaceae) are commonly grown for both cut flowers and landscape plants, Phenacoccus hakeae may be spread through international plant trade. The biology of the mealybug is unknown.

Worldwide Distribution: Phenacoccus hakeae is native to New South Wales, Australia. Its presence in shipments from the Netherlands suggests that it may also be present in some other countries that trade in Proteaceae.

Official Control: Phenacoccus hakeae is listed as an injurious animal on Japan’s plant pest quarantine list³.

California Distribution: In California, Phenacoccus hakeae was first known from an incursion into the environment of Los Osos, San Luis Obispo County. A follow-up survey indicates that the mealybug should be considered “established by survey” in San Luis Obispo County. In addition to Los Osos, populations have been found in the cities of Morro Bay, Shell Beach, Arroyo Grande, San Luis Obispo, Grover Beach, Cayucos, and Pismo Beach.

California Interceptions: Phenacoccus hakeae has been found in nurseries in both San Luis Obispo and Santa Barbara counties.

The risk Phenacoccus hakeae would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Proteaceae are commonly grown as ornamental plants in California and are common in the nursery industry. Phenacoccus hakeae is expected to be able to establish wherever these plants are grown. The mealybug receives a High (3) rating in this category.

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

2) Known Pest Host Range: Phenacoccus hakeae is only known to feed on plants in the family Proteaceae. P. hakeae 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: Phenacoccus hakeae has demonstrated its ability to disperse long distances through the trade of ornamental plants and flowers. Mealybugs may also be dispersed by wind. They are capable of rapid reproduction. Phenacoccus hakeae receives a High (3) in this category.

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

4) Economic Impact: Phenacoccus hakeae is not documented as a pest anywhere in scientific literature. However, mealybugs may cause significant problems for protea grown for cut flowers by contaminating flowers by their presence, honeydew, and sooty mold⁴. Cut flowers are a $477 million industry in California; other states and nations might reject infested flowers. Since Phenacoccus hakeae may increase production costs and trigger the loss of markets for proteas, the mealybug receives a Medium (2) rating in this category.

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

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

5) Environmental Impact: There are no plants listed as threatened or endangered in California that are expected to be hosts of Phenacoccus hakeae. Populations of the mealybug have been found established in residential areas and a botanical garden and do not appear to be triggering any additional treatment programs. Furthermore there is no evidence that any residents are replacing infested plants with alternative species. Since Phenacoccus hakeae appears to be established in the environment and is not causing any significant environmental impacts it receives a Low (1) rating 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 Phenacoccus hakeae: 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: Phenacoccus hakeae is widely established in the environment of San Luis Opispo County. The mealybug receives a Medium (-2) 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: Low (8)

Uncertainty:

Several species of Hakea plants are considered invasive weeds in some places; Phenacoccus hakeae may be a valuable natural enemy of these weeds or an indicator of their presence. Some mealybugs in one sample collected from Los Osos had been parasitized (PDR FR0P06009429). It is possible that parasitoids, either native to California or introduced along with the mealybugs, are helping to mitigate impacts of this new pest. It is also possible that species present in additional nations may be junior synonyms of Phenacoccus hakeae, and that the worldwide distribution of the mealybug may be greater.

It is possible that the natural habitat of Phenacoccus hakeae is sufficiently remote that its host range is not well documented. It is possible that it could colonize many other plants. High populations of the mealybug might trigger additional treatment programs in the nursery industry or by residents who find infested ornamental plants unacceptable. Large infestations of the mealybug could cause minor alterations of urban landscaping as residents and landscapers replace infested plants with alternative species.

Conclusion and Rating Justification:

Phenacoccus hakeae has established a widespread distribution on Proteaceae in San Luis Obispo County. It does not appear to be having any significant economic or environmental impacts. Therefore, a C rating is justified.

References:

²http://www.aphis.usda.gov/import_export/plants/plant_imports/federal_order/downloads/2010/NetherlandsCutFlowersRevised.pdf

³http://www.ippc.int/file_uploaded/1359088733_qp_list_25July2012.pdf

⁴Mazzeo, G., J. C. Franco, and A. Russo. 2009. A new Paracoccus species from Palaearctic region (Hemiptera, Sternorrhyncha, Coccoidea, Pseudococcidae) . Zootaxa 2274: 62–68 http://www.mapress.com/zootaxa/2009/f/zt02274p068.pdf

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

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.

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.

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:

– 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

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