The effects of sublethal pesticide residues and flight on codling moth, Cydia pomonella (Linnaeus), obliquebanded leafroller, Choristoneura rosaceana (Harris) and convergent ladybird beetle, Hippodamia convergens (Guérin-Méneville)
Teah J. Smith and Vincent P. Jones
Washington State University Tree Fruit Research and Extension Center, 1100 N Western Ave, Wenatchee, WA
The codling moth (CM), Cydia pomonella (Linnaeus) and obliquebanded leafroller (OBLR), Choristoneura rosaceana (Harris) are both important tortricid pests of apple in North America. We evaluated the effects of ten sublethal pesticide residues on the dispersal capabilities of CM and OBLR using digital flight mills in the laboratory. Three parameters were used to evaluate pesticide effects on the dispersal capabilities of these insects: average flight duration, average flight distance, and average number of flights. Esteem was the only pesticide that did not affect CM or OBLR flight parameters. Altacor and Cyazypyr significantly reduced all three parameters for both sexes of CM and OBLR. Because of the extreme effects of Altacor and Cyazypyr on CM and OBLR dispersal, we tested these two pesticides on adult convergent ladybird beetles, Hippodamia convergens (Guérin-Méneville)) to assess their impact on a generalist predator. Both pesticides had no significant effects on the dispersal ability of the convergent ladybird beetle, showing a clear effect on the moths but not the predator. The data show that in situations where dispersal of either CM or OBLR from an outside source is likely, proper choice of insecticide may limit their dispersal into the orchard while preserving biological control from convergent ladybird beetle.