Tag Archives: Diptera

Diptera, Insects, Mites & Earthworms

Ophiomyia kwansonis Sasakawa: Daylily Leafminer

March 3, 2016 Jason Leathers

California Pest Rating for

Ophiomyia kwansonis Sasakawa: Daylily Leafminer

Diptera: Agromyzidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

June 23, 2015 Dr. Martin Hauser tentatively identified an intercepted insect as Ophiomyia kwansonis. This is the first time this insect has been intercepted by CDFA and a pest rating proposal is required to determine future direction on this insect.

History & Status:

Background: Ophiomyia kwansonis is a leafmining fly that feeds on the leaves of daylilies (Hemerocallis spp.)^1,2. Adult female flies typically lay eggs near the tip of the leaf blade¹. As larvae feed they create mines that appear as long, prominent, whitish lines¹. Larvae pupate in mines, often near the leaf base¹. Mining does not kill plants¹. Daylily leafminer may be transported long distances when infested daylilies are moved.

Worldwide Distribution: Ophiomyia kwansonis is native to Japan and Taiwan². In March 2011 it was first found in the United States in a nursery in Florida¹ and by 2014 had been found in Alabama, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Mississippi, Missouri, New Hampshire, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, and West Virginia². It has also spread to Europe¹.

Official Control: Ophiomyia kwansonis is not listed as a harmful organism by any states or nations³ and is not known to be under official control in any locations.

California Distribution: No official samples of Ophiomyia kwansonis have ever been collected in California. However, there is a published report of a photograph from Irvine (Orange County) that shows a plant that has likely been damaged by the fly⁴.

California Interceptions: Ophiomyia kwansonis has only been intercepted once by CDFA on a shipment of daylilies (Hemerocalis sp.) from Delaware to Contra Costa County (PDR 070P06223714).

The risk Ophiomyia kwansonis (daylily leafminer) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Ophiomyia kwansonis is widespread in the eastern United States and it is expected to be able to establish anywhere that daylilies are grown. Daylily leafminer 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: Ophiomyia kwansonis is only known to feed on daylilies (Hemerocallis) and receives a Low (1) in this category.

Evaluate the host range of the pest. Score:

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

3) Pest Dispersal Potential: Ophiomyia kwansonis has a high reproductive potential. It can complete 2-3 generations per year in cooler climates and breed continuously under warm conditions^1,2. The leafminer may disperse locally by flying and may be transported long distances as eggs, larvae, or pupae on infested daylilies. Daylily leafminer receives a High (3) in this category.

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

– Low (1) does not have high reproductive or dispersal potential.
– Medium (2) has either high reproductive or dispersal potential.
– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: If Ophiomyia kwansonis were to become established in California it is not expected to lower crop yields. It is likely to lower the value of daylily nursery stock by disfiguring plants with its presence. The leafminer is not expected to disrupt any markets, change cultural practices, vector other organisms, injure animals, or interfere with water supplies. Daylily leafminer receives a Low (1) in this category.

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

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

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

5) Environmental Impact: If daylily leafminer were to become established in California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It is not likely to directly affect threatened or endangered species or disrupt critical habitats. In Florida growers are advised to remove and destroy obviously mined leaves¹. No new chemical treatment programs are expected. Daylily leafminer is expected to significantly impact daylilies which are common ornamental plants. Ophiomyia kwansonis 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 Ophiomyia kwansonis (Daylily Leafminer): 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: Daylily leafminer has not 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 (10)

Uncertainty:

Eggs and young larvae of daylily leafminer are very difficult to detect in visual inspections. Given the wide distribution of the fly in the eastern United States and rapidity of its spread it is possible some of the flies may have already entered California.

Conclusion and Rating Justification:

Ophiomyia kwansonis has not been found in California and is expected to have significant impacts on the nursery industry and ornamental plantings if it becomes established in the state. A “B” rating is justified.

References:

¹ Steck, Gary J. and Gaye L. Williams. 2013. Daylily Leafminer, Ophiomyia kwansonis Sasakawa (Diptera: Agromyzidae), new to North America, including Florida. Pest Alert. Florida Department of Agriculture and Consumer Services, Division of Plant Industry. DACS-P-01807. http://freshfromflorida.s3.amazonaws.com/ophiomyia-kwansonis.pdf

² Bethke, James A. 2014. Insect Hot Topics: Daylily leafminers. UCNFA News. http://ucanr.edu/sites/UCNFAnews/Insect_Hot_Topics/Daylily_leafminers/

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

⁴ Williams, Gaye L. and Gary J. Steck. 2014. Ophiomyia kwansonis Sasakawa (Diptera: Agromyzidae), the Daylily Leafminer, an Asian Species Recently Identified in the Continental United States. Proceedings of the Entomological Society of Washington 116(4): 421-428.

Responsible Party:

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

Comment Format:

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

Example Comment:

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

♦ Posted comments will not be able to be viewed immediately.

♦ Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦ Comments may be edited prior to posting to ensure they are entirely germane.

♦ Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: B

Posted by ls

Diptera, Insects, Mites & Earthworms

Zaprionus indianus Gupta: Striped Vinegar Fly

December 16, 2015 Jason Leathers

California Pest Rating for

Zaprionus cf. indianus Image Citation: Darren J. Obbard (obbardlab) — *Zaprionus cf. indianus*
Image Citation: Darren J. Obbard (obbardlab)

Zaprionus indianus Gupta: Striped Vinegar Fly

Diptera: Drosophilidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

On July 29, 2015 Dr. Stephen Gaimari confirmed the identification of Zaprionus indianus from a sample submitted by a resident in Los Angeles County. This find was soon confirmed by official samples. A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background: Zaprionus indianus is a generalist small fly that feeds on fallen fruit and fruit on the tree¹. In most host species, fruit damage is necessary to allow the fly access to fruit¹. However, it is able to attack undamaged figs by laying eggs at the ostiole¹. Infestations of Zaprionus indianus may reduce the yield of commercial fig by 40-80%¹. Striped vinegar fly may be transported long distances when infested fruit is moved or by researchers who study model organisms in the family Drosophilidae.

Worldwide Distribution: Zaprionus indianus is native to Africa, the Middle East, and southern Eurasia¹. It was first found in Brazil in 1999 and rapidly spread through that nation and Uruguay¹. It was then found in Mexico in 2002², Panama in 2003², Florida in 2005¹, Pennsylvania in 2011³, Virginia in 2012², and Utah and Oklahoma in 2015⁸. It has also been reported in other states but records are not known to be verifiable (Michigan, Texas, Arizona, California, Mississippi, Louisiana, South Carolina, Wisconsin, and Connecticut)^6,9. One author reports that this fly is established “throughout the western USA”⁷.

Official Control: Zaprionus indianus is listed as a harmful organism by Japan and the Republic of Korea⁴.

California Distribution: Zaprionus indianus is only confirmed to be established in Los Angeles County.

California Interceptions: Zaprionus indianus has never been intercepted by CDFA.

The risk Zaprionus indianus (Striped vinegar fly) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Zaprionus indianus has a widespread distribution in eastern North America from Pennsylvania to Florida corresponding with much of California. Striped vinegar fly is likely 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:

2) Known Pest Host Range: Zaprionus indianus feeds on a wide variety of damaged fruit. The only undamaged fruit it is known to attack is figs. 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: Since it was first found in Brazil in 1999 Zaprionus indianus has rapidly colonized much of the Americas. It breeds continuously under favorable conditions and each female produces many offspring. It can be transported long distances when infested fruit is moved. Striped vinegar fly receives a High (3) in this category.

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

4) Economic Impact: California leads the nation in fig production. Growers in the state produce 96% of the nation’s figs on 7,300 acres for a total crop value of $23.1 million⁵ in 2013. If Zaprionus indianus were to establish in fig production areas it is likely to significantly reduce yields. In South America it is also reported to be an important pest of oranges and peaches but this is probably due to cultural practices where fruit is allowed to over-ripen on the tree^2,3. It has also been found to be abundant in eastern U.S. vineyards but has not been documented causing any economic damage^3,6. Zaprionus indianus is expected to increase crop production costs in fig orchards, as some fig growers in areas where the fly is established place a sticker over each fruit ostiole as a control measure³ or may treat. Zaprionus indianus also has the potential to disrupt fig and a wide variety of fresh fruit markets as both Japan and Korea list the fly as a harmful organism⁴. Striped vinegar fly 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: If Zaprionus indianus were to establish in California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It is not likely to affect any threatened or endangered species or disrupt critical habitats. It may trigger new treatment programs in fig orchards and by residents who grow figs for consumption. Figs are grown in home/urban gardens and will be significantly impacted by this pest. Striped vinegar fly 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 Zaprionus indianus (Striped Vinegar Fly): 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: Zaprionus indianus is confirmed to be established in Los Angeles County and is reported to be established in San Diego. It receives 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: Medium (12)

Uncertainty:

It is possible that Zaprionus indianus may be able to expand the range of undamaged fruit it feeds on beyond fig in California.

Conclusion and Rating Justification:

Zaprionus indianus has established a localized distribution in California and is expected to have significant economic and environmental impacts as it expands its range in California. Impacts are expected to be limited to fig. A “B” rating is justified.

References:

¹ Van der Linde, Kim, Gary J. Steck, Ken Hibbard, Jeffry S. Birdsley, Linette M. Alonso, and David Houle. 2006. First records of Zaprionus indianus (Diptera: Drosophilidae), a pest species on commercial fruits from Panama and the Untied States of America. Florida Entomologist 89(3):402-404. http://www.bioone.org/doi/pdf/10.1653/0015-4040%282006%2989%5B402%3AFROZID%5D2.0.CO%3B2

² Markow, Therese Ann, Giovanni Hanna, Juan R. Riesgo-Escobar, Aldo A. Tellez-Garcia, Maxi Polihronakis Richmond, Nestor O. Nazario-Yepiz, Mariana Ramierez Loustalot Laclette, Javier Carpinteyro-Ponce, and Edward Pfeiler. 2014. Population genetics and recent colonization history of the invasive drosophilid Zaprionus indianus in Mexico and Central America. Biological Invasions 16: 2427-2434. http://link.springer.com/article/10.1007%2Fs10530-014-0674-5#page-2

³ Joshi, Neelendra K., David J. Biddinger, Kathleen Demchak, Alan Deppen. 2014. First report of Zaprionus indianus (Diptera: Drosophilidae) in commercial fruits and vegetables in Pennsylvania. Journal of Insect Science http://jinsectscience.oxfordjournals.org/content/14/1/259

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

⁵ California Department of Food & Agriculture. California Agricultural Production Statistics 2014 Report. http://www.cdfa.ca.gov/Statistics/PDFs/CropYearStats2013_NASS.pdf

⁶Sigler, Derrek. 2012. New fruit fly spreading across country. FGN Fruit Grower News. http://fruitgrowersnews.com/index.php/magazine/article/new-fruit-fly-spreading-across-country

⁷ Van der Linde, Kim. 2010. Zaprionus indianus: species identification and taxonomic position. Drosophila Information Service 93:95-98. http://www.ou.edu/journals/dis/DIS93/van%20der%20Linde%2095.pdf

⁸ Survey Status of Drosophilid Fig Fly – Zaprionus indianus. http://pest.ceris.purdue.edu/capsreview.php?code=IOAPAQA

⁹ Van det Linde, Kim. Zaprionus indianus: taxonomic position and species identification. http://www.kimvdlinde.com/professional/Zaprionus%20indianus.html

Responsible Party:

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

Comment Format:

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

Example Comment:

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

♦ Posted comments will not be able to be viewed immediately.

♦ Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦ Comments may be edited prior to posting to ensure they are entirely germane.

♦ Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating: B

Posted by ls

Diptera, Insects, Mites & Earthworms

Eumerus figurans (Walker): Ginger Maggot

March 24, 2015 Jason Leathers

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:

– 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: 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:

– 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: Eumerus figurans is considered a secondary pest of ginger and there appears to be more literature published on the fly’s role as a pollinator than a pest. It is not expected to lower any crop yields in California. Ginger maggot is likely to be considered a quarantine pest by Iceland³, Bermuda³, and Japan³ and has the potential to disrupt exports of ginger, lily, or narcissus bulbs to those markets. However, Eumerus figurans is unlikely to establish in Iceland and is already present on Nansei Island in Japan. Lost markets may therefore be limited to exports of ginger, lily, and narcissus bulbs to Bermuda. The fly may also increase crop production costs if growers manage populations of the flies. Eumerus figurans is not expected to negatively change normal cultural practices, vector pestiferous organisms, injure animals, or interfere with water supplies. It receives a Medium (2) in this category.

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

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

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

5) Environmental Impact: If Eumerus figurans were to enter California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. Ginger maggot is not expected to directly affect threatened or endangered species or disrupt critical habitats. It is possible that the flies could trigger new treatment programs in the nursery industry, ginger gardens, or by residents who consider flies a nuisance. Ginger maggot is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings. Eumerus figurans receives a Medium (2) in this category.

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

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.
B. The pest could directly affect threatened or endangered species.
C. The pest could impact threatened or endangered species by disrupting critical habitats.
D. The pest could trigger additional official or private treatment programs.
E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact. Score:

– Low (1) causes none of the above to occur.
– Medium (2) causes one of the above to occur.
– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Eumerus figurans (Ginger Maggot): Medium (10)

Add up the total score and include it here.

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

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

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

Final Score:

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

Uncertainty:

There 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

March 24, 2015 Jason Leathers

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:

– 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

Diptera, Insects, Mites & Earthworms

Horidiplosis ficifolii Harris: An Ornamental Fig Pest

March 16, 2015 Jason Leathers

California Pest Rating for

Horidiplosis ficifolii: an ornamental fig pest — *Horidiplosis ficifolii*: an Ornamental Fig Pest
Image Citation: Jakub Beránek

Horidiplosis ficifolii Harris: An Ornamental Fig Pest

Diptera: Cecidomyiidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

On November 14, 2014, Dr. Martin Hauser identified Horidiplosis ficifolii on ornamental shrubs in San Diego (PDR 370P06228129). This is the first time this pest has been found in California. A pest rating proposal is needed.

History & Status:

Background: Horidiplosis ficifolii is a gall midge that forms galls on the leaves of ornamental Ficus spp¹. Known hosts include Ficus microcarpa^1,2, F. retusa², F. nitida², and F. panda². The gall midge may spread long distances when infested host plants are moved.

Worldwide Distribution: Horidiplosis ficifolii is native to China, Taiwan, and Japan. From there it has spread to Florida and greenhouses in Europe.

Official Control: Horidiplosis ficifolii is not known to be under official control in any other states or nations³.

California Distribution: Horidiplosis ficifolii has only been found in San Diego.

California Interceptions: Horidiplosis ficifolii has never been intercepted in regulatory situations in California.

The risk Horidiplosis ficifolii would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Ficus plants are commonly grown in California and Horidiplosis ficifolii is likely to establish where they are grown. The gall midge 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: Horidiplosis ficifolii is only known to feed on four species of plants in the genus Ficus. 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: Gall midges can produce many offspring and may move long distances through commerce in infested host plants. They may also be dispersed locally by wind. Horidiplosis ficifolii receives a High (3) in this category.

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

4) Economic Impact: Horidiplosis ficifolii may increase the production cost of Ficus spp. nursery stock and lower the value of infested plants. It is not expected to lower crop yield, trigger lost markets, change cultural practices, vector pestiferous organisms, injure animals, or interfere with water supplies. The gall midge receives a Low (1) 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: Horidiplosis ficifolii is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. The gall midge is not expected to affect threatened or endangered species or disrupt critical habitats. The gall midge may trigger new treatment programs in the nursery industry and by residents who find infested plants unsightly. Ficus spp. are commonly grown as ornamentals in California and may be significantly affected by this insect. Horidiplosis ficifolii receives a High (3) in this category.

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

Score the pest for Environmental Impact. Score:

– Low (1) causes none of the above to occur.
– Medium (2) causes one of the above to occur.
– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Horidiplosis ficifolii: 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: Horidiplosis ficifolii is only known from an incursion into San Diego. It 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 (11)

Uncertainty:

There have been no formal surveys for Horidiplosis ficifolii in California. It is possible that the gall midge may be more widespread. However, the species is relatively new to science, it was just described in 2003. It is possible that it may emerge as a more serious pest as it expands its range.

Conclusion and Rating Justification:

Due to its narrow host range the entry of Horidiplosis ficifolii is expected to have limited economic consequences. However, it may have significant environmental impacts by triggering new chemical treatments in the nursery industry and by residents who find infested ornamental plants unsightly. A “B” rating is justified.

References:

¹Steck, Gary J. and Scott Krueger. An Ornamental Fig Pest, Horidiplosis ficifolii Harris (Diptera: Cecidomyiidae), Genus and Species New to Florida and North America. Florida Department of Agriculture and Consumer Services. http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Plant-Industry-Publications/Pest-Alerts/Pest-Alerts-An-Ornamental-Fig-Pest-Horidiplosis-Ficifolii-Harris-Diptera-Cecidomyiidae

²Beránek, Jakub and Ivana Šafránková. 2010. First record of Horidiplosis ficifolii Harris 2003 (Diptera: Cecidomyiidae) in the Czech Republic. Plant Protect. Sci. 46(4): 185-187. http://www.agriculturejournals.cz/publicFiles/31854.pdf

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