California Pest Rating for
Zaprionus indianus Gupta: Striped Vinegar Fly
Pest Rating: B
PEST RATING PROFILE
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:
– 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: 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:
– 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: 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 tree2,3. It has also been found to be abundant in eastern U.S. vineyards but has not been documented causing any economic damage3,6. 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.
Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.
–Not established (0) Pest never detected in California, or known only from incursions.
–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).
–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.
–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.
The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)
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.
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
6 Sigler, 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
Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.
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Pest Rating: B
Posted by ls