Sevin Versus Cyfluthrin in Cucurbit Bait for Western Corn Rootworm Beetles

Abstract

Abstract Four-day old, laboratoryreared male WCR beetles were assayed under clear plastic cones (11.5 cm diam., 9 cm ht.) placed on black poster board and set upon a laboratory countertop. Ten WCR were added per cone. WCR were fed until about 1 h before the bioassay. The narrow end of a no. 8 cork was fitted about 0.5 cm into an opening (2 cm diam.) at the top of the cone. This end was bored (1 cm depth, 1.3 cm diam.), and the bore was filled with 1.5 g of toxic bait. Bait contained 2% (wt.) carbaryl, 0.024% cyfluthrin, 0.12% cyfluthrin, or no insecticide. Carbaryl was a 40% AI (wt.) formulation of Sevin XLR, and cyfluthrin was a 93% pure technical grade material. Each bait contained 5% powdered root of buffalo gourd (Cucurbita foetidissima H.B.K.), which acted as a feeding stimulant. The remainder of the bait was composed of a 3:1 (w/w) mixture of artificial patty diet and corn oil. Treatments were arranged in a randomized complete block design with 5 replications. Moribund beetles were counted at 30 min and 1 h.