Timing is Right for a Slug Fest

June 7, 2005

WOOSTER, Ohio — Slugs are making a buffet out of slow developing corn and soybeans, and growers need to be scouting their fields now for potential treatment.

A cool, moist Ohio spring has caused emergence delays in both crops, and in some parts of the state, growers have been forced to replant. The hold-up has given slugs time to hatch out, grow to feeding size, and become a potential threat to young plant leaves.

"The slugs are hitting right now," said Ron Hammond, an Ohio State University research entomologist with the Ohio Agricultural Research and Development Center. "With the lousy spring weather we had, both crops overall are pretty short right now and that's just perfect timing with slugs ready to feed."

The juvenile stage of the slug creates the most damage to crops and its voracious appetite and large densities can be devastating for farmers who have had a history of slug problems. Upon hatching in early to mid-May, the slug will begin feeding on anything that is planted in the field, whether it's corn, soybeans or alfalfa. Slug feeding can cause significant reductions in corn yields and total stand loss in soybeans.

Hammond said that based on stages of slug development, the pests are larger throughout central Ohio than they are in northern Ohio. Using that as a marker, entomologists are able to give growers a heads-up about a week in advance to any heavy slug feeding in any given part of the state.

"Our recommendation to growers is that if they have a history of slugs in their fields, they need to get out there now and start checking for the presence of slugs and crop injury," said Hammond. "If treatment is required, a molluscicide bait will do."

Hammond has been actively scouting fields throughout northeast Ohio for the past several days.

"In some cases where growers were able to catch the slugs early with treatment, defoliation is not that bad," he said. "But there will be some cases where we are looking at total defoliation, and even with some soybean in the trifoliate stage, for example, you are not going to get a good plant out of it."

Author(s): 
Candace Pollock
Source(s): 
Ron Hammond