Researcher fighting slugs with worm parasite

COLUMBUS, Ohio -- Parwinder Grewal is working on research he hopes will wipe out slugs before they do the same to farmers' fields.

The Ohio State University researcher and entomologist is trying to discover a microscopic parasitic worm known as a nematode that crawls into a slug through its breathing pore, multiplies and kills the pest in about a week.

Such a discovery would be a blessing for farmers whose crops are sometimes devoured by slugs.

"Last year in Ohio, because of the good rains we had in the summer, slug populations were so high that some farmers had actually lost their entire corn crop," he said.

David Graham, a Wayne County farmer who has about 1,000 acres of corn and soybeans, said he has had entire fields wiped out in three to five days.

"You can still make a profit if you can get in there and get it treated," Graham said. "If you don't, you'll be wiped out."

Farmers can fight slugs with metaldehyde, a toxic bait that lasts 10 days to two weeks in dry weather, Graham said. But the bait is costly. Graham estimates he has spent about $6,000 this year killing slugs.

Grewal said farmers' problems could be solved by a nematode that has been found in England and is being mass-produced to control slugs in Europe.

Looking for local variety

If Grewal could find that nematode in a North American slug, it could be used in the United States. Grewal said he may also find another nematode that is native to North America and works as effectively as the European nematode.

Grewal is uncertain how long his research will continue. If he can't find the European nematode here, he plans to ask the federal government to consider approving its use in the United States.

The Environmental Protection Agency and the U.S. Department of Agriculture would have to be certain the European nematode wouldn't harm the environment before it could be used in the United States, said David Chitwood, a research leader in the nematology lab at the Beltsville Agricultural Center in Beltsville, Md.

"If you're using a nematode that's already found in Ohio, for instance, that's probably going to be a bit more favorable for regulatory agencies than something from England, when you have to worry what other hosts it might have," Chitwood said.

Graham said he is excited about any option that would save him money in fighting the pests. But he said drawn-out research project won't do him any good.

"Anything that's cheaper and better is fine with me, but they can't spend 10 years working on it," Graham said. "I won't be in business by then. I have to feed my family between now and then."