'Cotton Candy' Could Replace Pesticides

February 17, 2002

EarthVision Environmental News

ITHACA, New York, February 15, 2002 - Agricultural pests may one day be

combated with a polymer developed by researchers at Cornell University that

physically resembles cotton candy, helping reduce the amount of toxic

pesticides needed for farming.

Ethylene vinyl acetate (EVA) has been tested by Hoffman, professor

of entomology and director of the New York State Integrated Pest Management

program at Cornell University, and his colleagues by producing nonwoven

fiber barriers that help keep insects from attacking a variety of plants.

EVA is identical to the material used in hot melt glue guns, and has been

nicknamed " cotton candy " by Hoffman because of its physical resemblance to

the popular treat.

" The best way to envision these barriers is to think of cotton candy just

like you buy at the circus, " Hoffmann said, " except remove 99 percent of the

fibers and what remains is a nonwoven multidimensional barrier that can be

strategically placed to interfere with insect behavior. "

The polymer forms webs that cover plants, helping prevent agricultural pests

such as corn earworms, cabbage maggots and onion maggots from destroying the

crop. Left untreated or unmanaged, cabbage maggots can destroy up to 90

percent of a cabbage crop and onion maggots can destroy 40 percent of an

onion crop. Relying on insecticides and other pesticides can, in the

long-term, lead to insects developing resistance to the chemicals, causing

further management problems.

Field experiments conducted by Hoffman found positive results when EVA

fibers were placed at the base of onion plants. Onion maggots laid an

average of 10.4 eggs on untreated plants and only 1.4 eggs on plants with an

EVA covering. When EVA was applied to young broccoli plants, Hoffman said it

prevented the leaves from unfurling for a week or two, but they eventually

broke free and were unaffected by the fiber.

" One day we hope to use fibers with proper characteristics for pest

repellence and timed degradation so that the barriers remain intact only as

long as necessary. The technology exists, and it's just a matter of pushing

forward with more research and development, " Hoffman noted.

EVA is being considered for use against a variety of other insects, birds

and possibly even deer.

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