‘Cotton Candy’ Latest in Insect Control

‘Cotton Candy’ Latest in Insect Control

No one ever said farming was a day at the circus, but farmers eventually might be able to exchange pesticides for an industrial grade polymer that looks and acts like cotton candy as a major weapon against agricultural pests.

Michael Hoffmann, Cornell University professor of entomology and director of the university's New York State Integrated Pest Management program, and his colleagues have been testing nonwoven fiber barriers made of ethylene vinyl acetate, or EVA, as a bug prevention device.

The polymer, identical to the material used in hot melt glue guns, can be extruded under pressure to form webs that cover plants and appear to ward off agricultural pests like onion maggots, cabbage maggots and corn earworms.

"The best way to envision these barriers is to think of cotton candy just like you buy at the circus," Hoffmann explained, "except remove 99% of the fibers and what remains is a nonwoven multidimensional barrier that can be strategically placed to interfere with insect behavior."

Hoffmann introduced the new pest management tool in his talk, "Novel Pest Management Tactics: Pushing the Envelope," at the 2002 New York State Vegetable Conference on Wednesday.

Nonwoven fiber barriers hold considerable potential for the management of onion maggots and cabbage maggots, Hoffmann said. Without any pest controls in place, as much as 90% of a cabbage crop can be destroyed, and as much as 40% of untreated onions can be wiped out.

Onion and cabbage fields now rely on insecticides applied during planting to control maggots. Long term reliance on insecticides is problematic because of the continuing threat of the development of resistance to the chemicals.

"The need for alternative control measures for both the cabbage maggot and the onion maggot is critical," said Hoffmann.

In Hoffmann's field cage experiments, the scientists learned that placing EVA fibers around the base of onion plants reduces the number of eggs laid by female onion maggots. EVA treated plants had an average of 1.4 eggs per plant compared with an average of 10.4 eggs for untreated plants.

During a field experiment, the researchers applied EVA to young broccoli plants. While the polymer appeared to inhibit the leaves unfurling for a week or two, the leaves broke free of the barrier and were unaffected by the fiber mat, said Hoffmann.

"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 added.

The weblike barriers also hold potential for several other insect pests, birds and maybe even deer, he said.