Slug activity is picking up, particularly in portions of the Midwest receiving regular rains, says John Tooker, Penn State University entomologist.
“In the past few weeks, I have seen corn, soybean, canola, alfalfa and small grains all with considerable slug damage,” Tooker says.
Typically, control options for slugs have been limited to deploying metaldehyde-based baits or homespun remedies like spraying nitrogen solutions at night. DuPont, however, has introduced a new option, issuing what’s called a “2(ee) recommendation” for the use of Lannate LV on field corn and soybeans in Pennsylvania, Delaware, Maryland, Virginia and West Virginia, Tooker says
The 2(ee) recommendations allow for uses of a pesticide that are consistent with its labeling, but do not officially add slugs to the label. Nevertheless, the restricted-use pesticide can used to target slugs on corn and soybeans, giving growers an additional slug control option, he says.
“I am not aware of any efficacy data, but I know that DuPont is pursuing these,” Tooker says. “It appears clear that Lannate LV is a contact poison with little residual activity. Therefore, the product would need to be sprayed in the evening or early morning when slugs, which are nocturnal, are active.”
Lannate LV contains the active ingredient methomyl and is a carbamate insecticide. Tooker urges no-tillers who be cautious when using the restricted-use pesticide, which has high acute toxicity to humans.
“Carbamates are notorious for their broad-spectrum toxicity to invertebrates, including beneficial insects, spiders and earthworms,” Tooker says. “The use of Lannate LV should not be considered lightly and the product should be used only when absolutely necessary.”
According to DuPont’s 2 (ee) Recommendation label, Lannate LV may be applied at 1½ pints per acre when slug populations reach locally determined economic thresholds and should be used every 5 to 7 days to maintain control.
"Since Lannate LV is a fast-acting contact herbicide, best results follow direct spraying of the target insect," DuPont's label notes.
Several restrictions apply to its use on field corn and soybeans, DuPont notes. For field corn, no more than 7½ pints of Lannate LV may be applied per acre during a growing season and no more than 10 applications of the insecticide may be applied per crop. Lannate LV may not be applied within 21 days of harvesting field corn.
No more than 4½ pints of Lannate LV may be applied per acre in a growing season to soybeans, no more than three applications of the product may be made per soybean crop and the insecticide may not be used within 14 days of harvest of the soybeans.