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Science Update

Virus Makes Moths Too Sick for Sex

A virus that prevents corn ear-worms from mating may become a new natural weapon. Each year, earworms and related insect pests damage about $5 billion worth of corn, cotton, and other crops worldwide. ARS scientists in Beltsville, Maryland, discovered the virus in 1994. They named it "gonad-specific virus" because it infects only the moth's reproductive organs. It deforms the female's ovaries and the male's testes. Scientists speculate that releasing virus-infected moths in crop fields would render sterile about 70 to 80 percent of their progeny. The rest might reproduce—but would transmit virus to their offspring. Beltsville scientists are trying to identify the virus' gene structure. They're also conducting a field test in cooperation with ARS colleagues in Stoneville, Mississippi. ARS has filed a patent application on use of the virus.

Ashok K. Raina, USDA-ARS Insect Biocontrol Laboratory, Beltsville, Maryland; phone (301) 504-6327.

Computers Put Weevils, Woodpeckers on the Map

Until now, red-cockaded woodpeckers and boll weevils have shared little but an ability to fly. The former are rare and endangered, while the latter are all too abundant—to the persistent exasperation of cotton growers. In Mississippi, however, both creatures are showing up on computer-generated maps. ARS scientists designed the color-coded maps to alert cotton growers as to whether, where, and when boll weevil numbers could be climbing to crop-threatening levels. But in a new pilot study, scientists with the federal Fish and Wildlife Service are adapting the maps. FWS scientists aim to monitor the red-cockaded woodpeckers living in a Mississippi wildlife refuge. That could help them design and evaluate ways to protect the birds and boost their numbers.

USDA-ARS Boll Weevil Research Laboratory, Mississippi State, Mississippi; phone (601) 323-2230.

ARS Kit Checks Fruits and Vegetables for Fungicide Residues

A new kit just entering the marketplace can verify that fungicide residues on the surface of fruits and vegetables are within safe levels. The fungicide, thiabendazole, protects potatoes, apples, bananas, lemons, oranges, and other produce from mold and rot. ARS researchers and colleagues from Millipore/Immuno-Systems, Bedford, Massachusetts, developed the kit. It will simplify safety checks by regulatory agencies, food processors, and retailers. Growers can use it too. The test can ensure that a thiabendazole concentration applied in a dip or spray can guard the harvest but will not leave excess residue. The kit uses customized proteins called monoclonal antibodies. In a liquid that contains bits of fruit or vegetable peel, the proteins bind to any fungicide present. This changes the liquid's color. The test takes about 4 hours, much less time than other methods.

David L. Brandon, USDA-ARS Foodborne Contaminants Research Unit, Albany, California; phone (510) 559-5783.

Threesome Is Berry Good News

Farmers and backyard gardeners in some parts of the country should discover three new strawberry cultivars available for the 1996 season. Last year, ARS geneticists and their cooperators from other institutions released Mohawk, Northeaster, and Delmarvel to nurseries. All three are early-maturing and disease resistant. In June, the plants produce firm, tasty fruit for shipping as well as for local fresh markets. Delmarvel appears best adapted to the Mid-Atlantic region. Northeaster is suited for frozen as well as fresh markets, and its name tells where in the United States it should grow well. Mohawk should thrive there and also in southeastern Canada.

USDA-ARS Fruit Laboratory, Beltsville, Maryland; phone (301) 504-6571.


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