RESIDUAL ACTIVITY OF INSECTICIDES UNDER FIELD CONDITIONS FOR CONTROLLING THE COLORADO POTATO BEETLE (COLEOPTERA, CHRYSOMELIDAE)

Data are presented on the residual activity of several insecticides against the Colorado potato beetle, Leptinotarsa decemlineata (Say), when applied to potato foliage under field conditions. Treated foliage was returned to the laboratory and fed to early (first and second), third, and fourth instars and adults. Bacillus thuringiensis Berliner subsp. tenebrionis (M-One) caused 85% mortality of early instars at 1 h after application, and <5% at 48 h. B. thuringiensis subsp. tenebrionis (M-Trak) caused 90% mortality of early instars at 1 h and 20% at 72 h. Oxamyl (Vydate) + endosulfan (Thiodan) caused 98% mortality of early instars at 1 h and 15% at 48 h. Esfenvalerate (Asana) caused 78% mortality of early instars at 1 h and 30% at 48 h. Cryolite (Kryocide) caused 100% mortality of early instars at 1 h and 90% mortality after 96 h.