Insecticide-bait Strategy

Scientist with USDA-ARS, the agricultural experiment stations of several midwestern states, and private industry, cooperatively developed a new corn rootworm management tool based on suppression of adults using an environmentally friendly approach. The premise of this strategy is to kill beetles before they lay the majority of their eggs and thus prevent economic infestations of larvae from occurring if corn is planted in the successive year.

The new tactic uses behavior modifying chemicals (cucurbitacin) that are specific for corn rootworm beetles and that induce them to feed compulsively on a bait formulation. The primary components of these baits are cucurbitacins, bitter tasting compounds that attract beetles and repel non-target insects.

Cucurbitacins do not act as long-range attractants, but do increase rootworm feeding activity and arrest adults at feeding sites. Cucurbitacins are present in most plants of the family Cucurbitaceae. They are found in high concentrations in roots in the wild growing buffalo gourd. Dried and ground roots of this plant, mixed with a small amount of insecticide (carbaryl) and a non-toxic edible carrier are the basic components of the bait formulations.

The primary bait marketed is SLAM® which is produced by Micro-Flo Co. This bait uses 95 to 98% less insecticide active ingredient than traditional corn rootworm beetle management programs. Baits can be applied to corn by airplane or ground sprayer. Bait droplets adhere to plant surfaces and are available for feeding by rootworm adults for several weeks under ideal field conditions. Beetles that feed on the bait are killed when they ingest carbaryl. Currently, SLAM® is the primary tool for corn rootworm management in the areawide management program.