Toxicity of Avermectin B1 to Larval Yellowjackets, Vespula maculifrons (Hymenoptera: Vespidae)

Abstract
Avermectin B1 produced both acute (within 24 h) and chronic (after 6 days of exposure) mortality of 5th-instar Vespula maculifrons (Buysson). An acute LC50 of 38.4 ppm and a chronic LC50 of 2.99 ppm avermectin in food were found. Concentrations of 0.01 and 0.1 ppm avermectin had no adverse effect on mature 5th instars. Between 1 and 10 ppm avermectin B1 in protein baits has the potential for controlling yellow jacket populations if a sufficient quantity reaches the nest.