Impact of Four Synthetic Pyrethroids on Major Natural Enemies and Pests of Apple in Pennsylvania1

Abstract

The impact of four synthetic pyrethroids upon major apple pests and natural enemies was studied in Pennsylvania orchards from 1975 to 1980, The pyrethroids were tested alone in dilute and airblast applications and at reduced rates in combination with standard insecticides recommended for use in Pennsylvania’s integrated pest management (IPM) system, These materials were generally very active against the codling moth, Laspeyresia pomonella (L.), the oriental fruit moth, Grapholitha molesta (Busck), an apple budmoth, Platynota idaeusalis (Walker), and the white apple leafhopper, Typhlocyba Pomaria McAtee, The pyrethroids showed some potential for reducing populations of the apple aphid, Aphis pomi De Geer. Fenvalerate and permethrin were somewhat active against mites, but European red mite, Panonychus ulmi (Koch), and twospotted spider mite, Tetranychus urticae Koch, populations generally reached highest densities on pyrethroid plots, The pyrethroids were very toxic to the predatory mites, Amblyseius fallacis (Garman) and Zetzellia mali (Ewing), but less toxic than standard insecticides to a mirid predator, Hyaliodes vitripennis (Say), Stethorus punctum (LeConte), the key natural enemy in Pennsylvania’s apple IPM program, also was susceptible to these pyrethroids, but results after applying low rates of pyrethroids for 3 years indicated possible selectivity in favor of S. punctum with these new chemicals. These studies indicated several potential avenues for the careful introduction of the synthetic pyrethroids into existing IPM programs for deciduous-tree fruits.