Effects of Synthetic Pyrethroids on Major Insect and Mite Pests of Apple1

Seasonal applications of synthetic pyrethroids for major apple insects were generally effective in the range of 1.5–12 g AI/100 liters. Pyrethroids gave better control of plum curculio, Conotrachelus nenuphar (Herbst), in the field than expected from mortality evaluations in the laboratory. Observed behavioral effects such as reduction in curculio feeding, adult lethargy, and avoidance reactions can contribute to total effect of crop protection. Seasonal applications of pyrethroids led to general resurgence of European red mite, Panonychus ulmi (Koch), in each year of use. Laboratory tests with the twospotted spider mite, Tetranychus urticae Koch, showed changes in feeding behavior in response to fenvalerate.