March 2011Volume 6, Issue 3

First Detector Network News

Highlights:• Additional Detections of the Spotted Wing Drosophila

• Mediterranean Fruit Fly Quarantine Area Established in Florida

• Laurel Wilt Detected in Miami-Dade County

• A New Documentary on the Asian Longhorned Beetle Released

In February’s newsletter, we reported on the latest detection of the spotted wing drosophila (Drosophila suzukii (Matsumara) Diptera: Drosophilidae) in Michigan. However, additional detections have been announced since then. Spotted wing drosophila has now been detected in California (2008), Oregon (2009), Florida (2009), Louisiana (2010), North Carolina (2010), South Carolina (2010), Washington (2010), Michigan (2010), Utah (2010), and Wisconsin (2010). It has been established in Hawaii since the 1980s. In light of these announcements, we thought we should provide you with additional images of the adult, larvae, and pupae to aid in the identification of this pest.

Remember that adults measure 2-3mm in length, have a yellow-brown body with dark bands on the abdomen, and red eyes. In addition, the males have a small black spot on the leading edge of its wing, near the tip (which results in this pest’s common name). The larvae are 3mm in length, white to cream in color, and without legs or even a recognizable head (i.e. a typical maggot appearance). The pupae are oval, reddish brown in color, and 2-3mm in length and have two small projections at one end.

Should you see this pest in any of the states in which it has been detected (and especially if you detect this pest in any state that is not

listed here), please contact your local county extension agency or state agriculture agency.

Additional Detections of the Spotted Wing DrosophilaStephanie Stocks, Department of Entomology and Nematology, University of Florida

Top images courtesy of Lyle Buss, University of Florida. Middle and bottom images courtesy of M. Reitmajer, copyright Oregon State University from their publication.

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The Florida Department of Agriculture and Consumer Services (FDACS) reported two Mediterranean fruit flies (Medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), collected during routine fruit fly monitoring in a residential area in Pompano Beach located in Broward County on February 10. In response, an eradication program has been implemented. FDACS began to systematically monitor for more Medflies by placing an additional 1,473 traps in a 51-square mile area quarantined zone around the positive find. As of yet, no additional Medfly detections have been reported, however weekly monitoring will continue until the eradication program is declared successful (negative trapping results for three Medfly life cycles following the last positive wild identification).

FDACS also set up a certification process for material moving in and out of the quarantine zone (which is still in effect). Homeowners within the zone cannot move any fruits of vegetables off their property and must pick up any fallen fruit and vegetables from the yard, disposing of them by double bagging them in plastic, securely tying them, and placing them in household waste, not yard waste. FDACS or federal representatives may also need access to homeowners’ property in order to check for the presence of Medfly. As an added security measure, FDACS has applied by hand the pesticide Spinosad (which has been approved for use on organic crops) within the 656 foot area surrounding the initial positive find.

Beginning February 27, sterile Medflies were released over the quarantine area. This Sterile Insect Technique is designed to prevent subsequent generations of wild Medflies from occurring. Female Medflies mate only once before laying their eggs. If you flood the vicinity with sterile males, the odds of the female finding a male with which she is able to reproduce are greatly reduced (i.e. this is a biocontrol technique – no pesticides are used). Officials can identify the sterile male Medflies from reproductive males using a special light. The sterile males have a dye incorporated into

their body that reflects the light making them fairly easy to identify (see image below).

Medflies cause serious damage to crops (particularly fruit) by making them inedible causing wide spread crop losses. They have over 260 different fruit, flowers, vegetable and nut hosts many of which are economically important to various regions in the U.S. (examples include: apple, apricot, avocado, citrus, coffee, grape, mango, peaches, and tomatoes). Furthermore, it can have a potentially devastating effect on local economies as trade restrictions for export to other countries and even to other states within the U.S. are implemented when a positive identification is made. Medfly is a native of sub-Saharan Africa that has spread to other areas in Africa, Asia, Australia, Central America, the Caribbean, Europe, and South America. It became established in Hawaii in 1910. Periodic outbreaks have occurred in Florida, California, and Texas, but have failed to become established thanks to early detection and a rapid response eradication effort.

Mediterranean Fruit Fly Quarantine Area Established in FloridaStephanie Stocks, Department of Entomology and Nematology, University of Florida

Top image courtesy of Stephanie D. Stocks, University of Florida (sterile male). Bottom image courtesy of Scott Bauer, USDA Agricultural Research Service, www.bugwood.org, #1317085.

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The redbay ambrosia beetle (Xyleborus glabratus Eichhoff Coleoptera: Scolytinae) is an invasive beetle from Southern Asia that was detected in the U.S. in 2002 in Savannah, Georgia. Since then, it has spread along the coasts of Georgia, South Carolina, Florida and Mississippi (where it is in only one county so far). It vectors a fungal pathogen (Raffaelea lauricola) that is highly destructive to redbays (Persea borbinia) as well as other members of the family Lauraceae such as: sassafras (Sassafras albidum), swamp bay (Persea palustris), pondspice (Litsea aestivalis), pondberry (Lindera melissifolia), and camphor (Cinnamomum camphora). The fungus is carried by the beetle from tree to tree as its food source where it grows the fungus in tunnels that it excavates within the tree. The name of the disease caused by this fungus is laurel wilt.

Symptoms of the disease include drooping leaves with a reddish or purplish discoloration to them in the beginning; however, the entire crown quickly turns completely brown. In addition, if you remove the bark, you will see black discoloration or streaking of the sapwood.

Signs of the beetle include small entry holes and tiny sawdust tubes produced when they excavate their tunnels. However, it is more common to see piles of sawdust around the base of the tree than the tubes themselves. Normally ambrosia beetles only attack dying trees, however, this beetle is known to attack both healthy and dying trees. Death of the

tree can occur in as little as 15 weeks after infestation.

The beetle itself is tiny (measuring around 2mm in length). It has a V-shaped abdominal tip, a shiny, hairless upper surface, and its color varies from dark to an orange brown. Not much is known about the biology of this beetle. In fact, egg and larva descriptions for this particular species have not been made. Research at the University of Florida’s Department of Entomology and Nematology on the biology of the redbay ambrosia beetle is currently underway to answer these basic questions.

Recently, three swamp bays in Miami-Dade County, Florida were confirmed to have laurel wilt. The importance of the detection of this disease in this particular county results from another tree species that is susceptible to laurel wilt – avocado (Persea americana). Avocado is an economically important plant in both Florida and California. In Florida, there are about 6400 bearing acres with 99% of these acres located in southwest Miami-Dade County. In the 2008-2009 growing season, avocado production was estimated at over $13.17 million. California typically produces 85 to 90% of the total U.S. avocado crop with 58,268 bearing acres in Southern California in the 2009-2010 growing year producing 534.5 million pounds of avocado with an estimated value of more than $402 million.

Continued on the next page

Laurel Wilt Detected in Miami-Dade CountyStephanie Stocks, Department of Entomology and Nematology, University of Florida

The NPDN is a network of state and federal officials, land grant universities, and First Detectors whose mission is to detect, diagnose, and disseminate information regarding high consequence plant disease or pests. The NPDN was established in 2002 in response to a need for greater agricultural security.

Over the past eight years the NPDN has grown into an internationally respected consortium of plant diagnostic laboratories.

The five regions that make up the NPDN are the: NEPDN, SPDN, NCPDN, GPDN, and WPDN.

Please feel free to browse the links to the various regions to get a better idea of what is going on in your part of the country.

About NPDN:

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Should laurel wilt become established in avocado groves in either of these states, the industry as a whole could suffer huge losses.

In addition, there is no cure for laurel wilt, therefore preventing the spread of the disease to uninfected areas is the priority right now. The movement of infected firewood from one area to another seems to be key to the spread

of this disease (along with many other pests and diseases) across large areas. Whatever you do, KEEP IT LOCAL, DO NOT MOVE FIREWOOD!

For more information on laurel wilt and the redbay ambrosia beetle, check out the educational materials page at www.protectingusnow.org.

Top images are of the female redbay ambrosia beetle while the bottom images are of the male. Images provided courtesy of Lyle Buss, University of Florida.

The Asian longhorned beetle (Anoplophora glabripennis Coleoptera: Cerambycidae) is an exotic beetle from Asia that threatens hardwood trees such as maple, birch, buckeye, willow, ash, and elm. It was probably introduced through shipments of packing material and was detected in 1996 in Brooklyn, New York. It has since been found in other areas of New York, New Jersey, Massachusetts, and Illinois. Eradication efforts are underway in those areas.

Emily Driscoll is the producer and director of the documentary Bugged: The Race to Eradicate the Asian Longhorned Beetle. This

is a wonderful and informative documentary on the affects this invasive has on forest ecosystems and what is being done to combat this pest.

Visit her website (www.buggeddocumentary.com) to find out where this movie is being screened or to set up a screening in your area.

A New Documentary on the Asian Longhorned Beetle ReleasedStephanie Stocks, Department of Entomology and Nematology, University of Florida

Image courtesy of Michael Bohne, www.bugwood.org, #1262001.

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Published by the Southern Plant Diagnostic Network (SPDN) © University of Florida. All rights reserved.

Editors: Carrie L Harmon and Stephanie D. Stocks

To submit news items in future editions of the newsletter, contact clharmon@ufl.edu or sstocks@ufl.edu. You can include a short descriptive

paragraph, links, and related images or documents – don’t forget to include author credits though.

First Detector Training Opportunities:• May 10 - Newark, New Jersey - First

Detector Training for new Master Gardeners - click here to register

Employment Opportunities:• Click here.

Do you tweet? • Click here for updates.

Upcoming Meetings:• June 5-7 - the Florida State Horticultural

Society Meeting will be held jointly with the Soil and Crop Science Society in St. Petersburg, Florida - click here for details.

• October 11-14 - the International Master Gardener Conference will be held in Charleston, West Virginia - click here for more details.

• November 6-8 - the third annual NPDN meeting will be held in San Francisco, California - click here for more information.