Pest Rating Proposals and Final Ratings

Pseudococcus elisae Borchsenius: Banana Mealybug

California Pest Rating for

Pseudococcus elisae Borchsenius: Banana Mealybug

Hemiptera: Pseudococcidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

Pseudococcus elisae is frequently intercepted by CDFA and requires a pest rating proposal to support its pest rating.

History & Status:

Background: Pseudococcus elisae is a polyphagous Neotropical mealybug that feeds on a variety of cultivated plants, but most often on banana and other Musaceae¹. Known hosts include: Annonaceae: sugar apple (Annona squamosa¹); Araceae: Aglaonema spp.¹, Dieffenbachia spp.¹; Musaceae: Musa spp.¹, latundan banana (Musa sapientum¹), plantain (Musa paradisiaca¹); Rubiaceae: robusta coffee (Coffea canephora¹), arabica coffee (Coffea arabica¹), Ixora spp.¹; Rutaceae: key lime (Citrus aurantifolia¹). Pseudococcus elisae may be transported long distances when infested plants or fresh plant parts are moved.

Worldwide Distribution: Pseudococcus elisae is native to the Neotropical region. It is established in Mexico³, Guatemala³, Honduras³, Panama³, Colombia³, Ecuador³, Brazil³, Chile³, and Cuba³. It was confirmed to be established in Hawaii in 1984².

Official Control: Pseudococcus elisae is listed as a harmful organism by Chile, Japan, the Republic of Korea, and Paraguay⁴.

California Distribution: Pseudococcus elisae has never been found in the environment of California.

California Interceptions: Between January 1, 2000 and December 31, 2014 Pseudococcus elisae was intercepted by CDFA’s high risk programs, border stations, and dog teams 97 times. Interceptions have occurred on bananas, cut flowers, nursery stock, and other fresh plant parts.

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

Consequences of Introduction:

1) Climate/Host Interaction: Pseudococcus elisae is a tropical species with a host range that includes some plants grown outdoors in the warmer regions of California (e.g. key lime, banana). If the mealybug were to enter the state it would likely be limited to regions where these host plants are available. It receives a Medium (2) in this category.

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

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

2) Known Pest Host Range: Pseudococcus elisae is known to feed on 10 species of plants in 5 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: Mealybugs 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. Pseudococcus elisae 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: Pseudococcus elisae may lower the value of nursery stock by disfiguring plants with its presence. Several of California’s trading partners consider the mealybug a harmful organism. It is possible that Pseudococcus elisae could disrupt markets for nursery stock and fresh fruit. The mealybug 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 agri5) cultural 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: Pseudococcus elisae 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 new treatment programs in the nursery industry and by residents who find infested plants unsightly. It is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. Pseudococcus elisae 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 Pseudococcus elisae: Medium (11)**

Add up the total score and include it here.

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

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

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

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

Final Score:

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

Uncertainty:

It is possible that the host range of Pseudococcus elisae could be greater than is presently known. It is also possible that most of the climate of California could be unsuitable for establishment of the species.

Conclusion and Rating Justification:

Pseudococcus elisae has never been found in California. If it were to enter the state significant economic impacts could be expected on the nursery and fruit industries. An “A” rating is justified.

References:

¹ Miller, Dug, Yair Ben-Dov, Gary Gibson, and Nate Hardy. ScaleNet. http://scalenet.info/validname/Pseudococcus/elisae/

²Beardsley, John W. 1986. Taxonomic Notes on Pseudococcus elisae Borchsenius, a Mealybug New to the Hawaiian Fauna (Homoptera: Pseudococcidae). Journal Series no. 2942 of the Hawaii Institute of Tropical Agriculture and Human Resource. 26(1): 31-34. https://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/11188/26_31-34.pdf?sequence=1

³CABI Invasive Species Compendium: Pseudococcus elisae (banana mealybug). http://www.cabi.org/isc/datasheet/45085

⁴USDA 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

Hymenoptera, Insects, Mites & Earthworms

Ochetellus glaber (Mayr): An Ant

California Pest Rating for

Ochetellus glaber (Mayr): An Ant

Hymenoptera: Formicidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

Ochetellus glaber is frequently intercepted by CDFA and presently has a temporary rating of “Q”. A pest rating proposal is required to establish a permanent pest rating.

History & Status:

Background: Ochetellus glaber is a species of ant that is adapted for living around the interface of open and scrub habitat¹. It often nests arboreally, under stones, or in dry fallen logs¹. The ants are generalist foragers that may feed on honeydew, insects, or worms. They sometimes forage in houses for fluids or sweets but are not considered a major house pest¹. Colonies have multiple queens and colonies may reproduce by budding when a queen and some workers move to a new area. This allows the ants to be transported long distances when nests or queens are moved as contaminating pests in commerce.

Worldwide Distribution: Ochetellus glaber is probably native to Australia. It was first found in New Zealand in 1927¹ and Hawaii in 1977². It has also invaded Japan and parts of Asia. It recently spread to Florida³.

Official Control: Ochetellus glaber is not known to be under official control in any other states or nations⁴.

California Distribution: Ochetellus glaber has never been found in the environment of California.

California Interceptions: Between January 1, 2000 and December 31, 2014 Ochetellus glaber was intercepted 199 times by CDFA’s high risk programs and dog teams. These interceptions have been on nursery stock and fresh plant parts from Hawaii. The ant was also intercepted once at a border station on beehives from Florida.

The risk Ochetellus glaber would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Ochetellus glaber is found in regions with similar climates to California. The ant can be expected to establish a widespread distribution in the state 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: Ochetellus glaber is a generalist forager that can feed on a wide variety of sources. 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: Ants are capable of rapid reproduction and can disperse long distances when colonies or queens are moved. Ochetellus glaber 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: Ochetellus glaber is not expected to lower crop yields or increase crop production costs. It is not expected to disrupt any markets for Californian agricultural commodities. It is not expected to change cultural practices or vector other pestiferous organisms. Ochetellus glaber is known to tend honeydew producing insects and may consume parasitoids, disrupting biological control of pests such as pink hibiscus mealybug⁵. The ants are not expected to interfere with water supplies. Ochetellus glaber receives a Low (1) in this category.

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

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

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

5) Environmental Impact: Invasive ants such as Ochetellus glaber may cause slow, long-term ecological changes that have potential to lower biodiversity, disrupt natural communities, or change ecosystem processes. They may also trigger new private treatment programs by residents who find infestations unacceptable and in the nursery industry. Ochetellus glaber 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 Ochetellus glaber: 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: Ochetellus glaber has never been found in California and receives a Not established (0) in this category.

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

Final Score:

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

Uncertainty:

Invasive ants such as argentine ant (Linepithema humile) are already widespread in California and occupy many of the niches that Ochetellus glaber might be expected to colonize. It is possible that competition from argentine ant may help preclude establishment of other invasive species such as Ochetellus glaber. There is some evidence that Ochetellus glaber is a species complex and should be considered two or more distinct species⁶.

Conclusion and Rating Justification:

Ochetellus glaber has never been found in California and is expected to have limited economic and significant environmental impacts if it were to establish here. An “A” rating is justified.

References:

¹ Landcare Research Manaaki Whenua. Ochetellus glaber fact sheet. http://www.landcareresearch.co.nz/publications/factsheets/Factsheets/ochetellus-glaber

²Kirschenbaum, Ranit and J. Kenneth Grace. 2008. Agonistic Interactions Among Invasive Ant Species (Hymenoptera: Formicidae) from Two Habitats on Oahu, Hawaii. Sociobiology 51(3): 543-553. http://manoa.hawaii.edu/ctahr/termite/aboutcontact/grace/pdfs/241.pdf

³ Deyrup, M. 2003. An updated list of Florida ants (Hymeoptera: Formicidae). Florida Entomologist 86:43-48. http://antkey.org/content/updated-list-florida-ants-hymenoptera-formicidae

⁴ USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). https://pcit.aphis.usda.gov/pcit/

⁵ González-Hernández, Héctor, Neil J. Reimer, and Marshall W. Johnson. 1999. Survey of the natural enemies of Dysmicoccus mealybugs on pineapple in Hawaii. BioControl 44: 47-58. http://link.springer.com/article/10.1023/A:1009954625169#page-2

⁶Hoffman, Benjamin D., Alan N. Andersen, and Xiang Zhang. 2011. Taxonomic confusion of two tramp ant species: Iridomyrmex anceps and Ochetellus glaber are really species complexes. Current Zoology. http://www.actazool.org/site_media/onlinefirst/downloadable_file/2011/06/30/11.1_incomplete_taxonomy_hinders_invasion_research.pdf

Responsible Party:

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

Pest Rating: A

Posted by ls

Kallitaxila granulata (Stål): A Planthopper

California Pest Rating for

Kallitaxila granulata (Stål): A Planthopper

Hemiptera: Tropiduchidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

The planthopper Kallitaxila granulata is frequently intercepted by CDFA on shipments of plant products from Hawaii. This organism is presently assigned a temporary rating of “Q”. A pest rating proposal is needed to determine future actions on this pest.

History & Status:

Background: Kallitaxila granulata is a moderately polyphagous planthopper that feeds on at least 24 species of plants in at least 19 families. Adults lay eggs singly or in clusters along leaf veins, typically on the underside of leaves². Nymphs and adults both feed on leaves. Known hosts include: Apocynaceae: Plumeria acuminata (plumeria)²; Asparagaceae: Cordyline fruicosa (ti)²; Asteraceae: Wedelia sp.³; Caprifoliaceae: Lonicera sp. (honeysuckle)³; Cibotiaceae: Cibotium chamissoi (hapuu)²; Convovulaceae: Ipomoea triloba (Aiea morning glory)³; Euphorbiaceae: Aleurites moluccana (kukui)², Euphorbia heterophylla³; Fabaceae: Erythrina sandwicensis (wiliwili)³; Erythrina variegata (India coral bean)², Lablab purpureus (lablab beans)³; Gleicheniaceae: Dicranopteris linearis (uluhe)²; Lamiaceae: Vitex sp.³; Malvaceae: Thespesia populnea (milo tree)³; Moraceae: Ficus benjamina (weeping fig)³; Myrtaceae: Metrosideros polymorpha (ohia-lihua)²; Psidium guava (guava)²; Polygonaceae: Coccoloba uvifera (sea grape)³; Rubiaceae: Coffea sp. (coffee)³; Rutaceae: Citrus paradisi (grapefruit)², Citrus sp.³; Scrophulariaceae: Myoporum acuminatum³; Thymelaeaceae: Wikstroemia sp. (akia)³; Verbenaceae: Lantana montevidensis³, . The planthopper has the potential to spread long distances through commerce in infested plants and plant products.

Worldwide Distribution: Kallitaxila granulata is native to the Philippines. From there it spread to Christmas Island, the Cook Islands, Vietnam, China, and Hawaii⁴.

Official Control: Kallitaxila granulata is not known to be under official control in any states or nations.

California Distribution: Kallitaxila granulata has never been found in the environment of California.

California Interceptions: Kallitaxila granulata is frequently intercepted on shipments of plant products from Hawaii including basil, betel, curry, ginger, malangai, orchids, and ti¹.

The risk Kallitaxila granulata (a planthopper) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Some of the known hosts of Kallitaxila granulata are widely grown as ornamentals (e.g., Ficus benjamina) and crops (e.g., citrus) in California. The planthopper is likely to establish wherever hosts are grown. The insect 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: Kallitaxila granulata is known to feed on at least 24 species of plants in 19 plant families. The host list for Kallitaxila granulata expanded greatly with its introduction to Hawaii. It is likely that the plant hopper would continue to colonize new plants if it established in California. This is likely to cause additional economic and/or environmental impacts that are not considered in this document. The planthopper 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: Planthoppers have high reproductive potential and may spread long distances through the movement of infested plants or plant products. Kallitaxila granulata receives a High(3) in this category.

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

4) Economic Impact: Kallitaxila granulata is not expected to lower crop yields. Because the planthopper has a limited distribution, its entry into California may disrupt some markets as it is likely to contaminate commodities with its presence. The planthopper may increase crop production costs, especially in the nursery industry, as growers treat to ensure clean plants. Kallitaxila granulata is not expected to negatively change cultural practices, vector pestiferous organisms, injure animals, or interfere with water supplies. The planthopper 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: Kallitaxila granulata is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. No plants listed as threatened or endangered species in California are expected to be hosts for the plant hopper, nor is the plant hopper expected to disrupt critical habitats. The leaf hopper may trigger additional private treatment programs within the nursery industry as some growers may treat in order to maintain nursery stock cleanliness. The leaf hopper is not expected to impact cultural practices, home/urban gardening, or ornamental plantings. Kallitaxila granulata 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 Kallitaxila granulata: 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: Kallitaxila granulata has not 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:

Kallitaxila granulata is frequently intercepted on shipments of plant products from Hawaii. Presumably, it has also been present on other shipments that were not intercepted and have entered the state. There have not been any formal surveys of California for this plant hopper. Therefore, it is likely that Kallitaxila granulata is either already present in parts of the state or that environmental conditions here are not conducive to establishment. The places where the planthopper is known to be established have humid tropical environments. The Mediterranean climate of California may not be suitable for the plant hopper.

Conclusion and Rating Justification:

Kallitaxila granulata has not yet been documented to cause significant economic or environmental impacts anywhere it has established. If the plant hopper were to enter California, economic impacts are expected to be limited to possible disruptions to host plant markets when the insect is found. Furthermore, production costs may increase in the nursery industry as new treatments could be triggered in order to maintain plant cleanliness. Environmental impacts are expected to be limited to these possible new chemical treatments. However, the plant hopper greatly expanded its host range when it was introduced to Hawaii. It is likely to continue to colonize new hosts in California. Due to potential economic and environmental impacts of the entry of Kallitaxila granulata into California, an “A”-rating is justified.

References:

¹Von Ellenrieder, Natalia. 2007. A planthopper (Kallitaxila granulata). California Plant Pest & Disease Report 23(1): 19. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCsQFjAC&url=http%3A%2F%2Fwww.cdfa.ca.gov%2Fplant%2FPPD%2FPDF%2Fkallitaxila_granulata.pdf&ei=kTe8U_3KDojPiwLM-IGACQ&usg=AFQjCNH2ilXv8591Cqo7A2UW721tVhR6fg&bvm=bv.70138588,d.cGE

²Yang, Pingjun, Andrei Alyokhn, and Russell Messing. 2001. Patterns of oviposition and parasitism of eggs of Kallitaxila granulata (Homoptera: Tropiduchidae), a newly invasive planthopper in Hawaii. Proc. Hawaiian Entomological Society 35: 77-83. http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/8104/9Yang.pdf?sequence=1

³Asche, Manfred. 2000. New state records of immigrant planthoppers in Hawaii (Homoptera: Fulgoroidea). Proc. Hawaiian Entomological Society 34: 185-187. http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/8409/Note2.pdf?sequence=1

⁴FLOW Hemiptera Database: http://hemiptera-databases.org/flow/?page=explorer&db=flow&lang=en&card=taxon&rank=species&id=9580

Responsible Party:

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

Pest Rating: A

Posted by ls

Lycorma delicatula White: Spotted Lanternfly

California Pest Rating for

Lycorma delicatula White: Spotted Lanternfly

Hemiptera: Fulgoridae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

On October 30, 2014 Duane Schnabel distributed information from the National Plant Board that Lycorma delicatula has been found in four counties in Pennsylvania and may have been distributed to other states. A pest rating proposal is needed to determine future direction on this pest.

History & Status:

Background: Lycorma delicatula is a fulgorid hopper that is known to feed on at least 41 species of trees and herbs^1. The spotted lanternfly has one generation per year and overwinters as eggs in an ootheca¹. In Korea, eggs hatch in mid-May and nymphs begin sucking saps from young stems and leaves¹. Nymphs do not fly and are particularly polyphagous, feeding on almost any plant they encounter. Their feeding produces large quantities of fluid, which covers stems and leaves¹. Infestations can weaken plants and eventually kill them¹. Adult spotted lanternfly can fly but tends to spread by walking. By September, many of the adults have moved to preferred hosts, if they are available¹. The strongly preferred host for adult feeding is tree of heaven (Ailanthus altissima) but they also prefer bee bee tree (Tetradium (=Evodia) daniellii) and Amur cork tree (Phellodendron amurense)¹. The insect will also feed on a wide variety of other plants including grapes (Vitis spp.) and stone fruit (Prunus spp.). Oothecae are typically deposited on trees with a smooth surface structure¹. The most likely pathway for long-distance spread of Lycorma delicatula is the movement of oothecae on infested nursery stock or possibly other objects.

Partial Host List: Betulaceae: Betula platyphylla¹ (Japanese white birch); Cornaceae: Cornus controversa¹ (wedding cake tree), C. kousa¹ (kousa dogwood), C. officinalis¹ (Japanese cornel); Elaeagnaceae: Elaeagnus umbellata¹ (Japanese silverberry); Juglandaceae: Juglans mandshurica¹ (Manchurian walnut); Meliaceae: Cedrela fissilis¹, Toona sinensis¹ (Chinese mahogany); Oleaceae: Syringa vulgaris¹ (lilac); Pinaceae: Pinus densiflora¹ (Japanese red pine); P. strobus¹ (eastern white pine); Rosaceae: Prunus serrulata¹ (Japanese cherry), P. yedoensis¹ (yoshino cherry); Rutaceae: Phellodendron amurense¹ (Amur cork tree), Tetradium daniellii¹ (bee bee tree); Salicaceae: Populus alba¹ (white poplar); Sapindaceae: Acer palmatum¹ (Japanese maple), Acer saccharinum¹ (silver maple); Simaroubaceae: Ailanthus altissima¹ (tree of heaven), Picrasma quassioides¹ (bitterwood); Ulmaceae: Zelkova serrata¹ (keyaki); Vitaceae: Parthenocissus quinquefolia¹ (Virginia creeper), Vitis amurensis¹ (Amur grape), Vitis vinifera¹ (grape vine).

Worldwide Distribution: Lycorma delicatula is native to the southern part of China and other subtropical regions of southeast Asia¹. It was not known to be invasive until it spread to Korea in 2006 and to Pennsylvania in 2014.

Official Control: Lycorma delicatula is not known to be under official control in any states or nations.

California Distribution: Lycorma delicatula has not been found in California.

California Interceptions: Lycorma delicatula has not been intercepted in California.

The risk Lycorma delicatula (spotted lanternfly) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Host plants are commonly grown in California and spotted lanternfly is likely to establish wherever they are found. Lycorma delicatula 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: Lycorma delicatula feeds on at least 41 species of plants in at least 14 families. These include multiple agriculturally important crops and common ornamentals in California. 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: Lycorma delicatula has only one generation per year and tends to move by walking but oothecae may be dispersed long distances by the movement of infested nursery stock or other items. Spotted lanternfly receives a Medium(2) in this category.

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

4) Economic Impact: Infestations of Lycorma delicatula may lower crop yields and increase production costs in economically important crops such as grape, stone fruit, and nursery stock. Since it entered Korea, the insect has caused considerable damage in vineyards. Although it is not yet under official control in any states or nations, the presence of this pest in agricultural commodities may cause trade disruptions due to its limited range in North America. Spotted lanternfly is not expected to change normal cultural practices, vector other organisms, or interfere with water supplies. Lycorma delicatula 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: Spotted lanternfly is not expected to lower biodiversity, disrupt natural communities or change ecosystem processes. It is not expected to directly affect endangered species or disrupt critical habitats. It may trigger new treatments in vineyards and stone fruit orchards and by residents who find infested plants unsightly. Spotted lanternfly may also significantly affect home/urban gardening by feeding on grapes and trees. Lycorma delicatula 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 Lycorma delicatula (Spotted Lanternfly): 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: Lycorma delicatula has not 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:

There have been no formal surveys for Lycorma delicatula in California. It may already be present in some localities.

Conclusion and Rating Justification:

Spotted lanternfly (Lycorma delicatula) has never been found in California and is likely to have significant economic and environmental impacts. An A-rating is justified.

References:

¹Kim, Jae Geun, Eun-Hyuk Lee, Yeo-Min Seo, and Na-Yeon Kim. Cyclic Behavior of Lycorma delicatula (Insecta: Hemiptera: Fulgoridae) on Host Plants. J Insect Behav (2011) 24: 423-435. http://ag.udel.edu/delpha/7969.pdf

Responsible Party:

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

Pest Rating: A

Posted by ls

Gymnaspis aechmeae Newstead: Fly Speck Scale

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

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:

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:

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.

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:

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.

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:

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:

– 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:

– 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.

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.

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 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