Selective Pesticides as Aids to Biological Control of Apple Pests1

Abstract

In orchard tests in West Virginia during 1952-54, the botanical insecticide ryania has given outstanding control of the codling moth comparable to that obtained with DDT. Pure ryania and the fungicides glyodin and captan are also nontoxic to predaceous mites of the genus Typhlodromus which effectively control phytophagous mite populations on unsprayed apple trees. Seasonal schedules of these materials in both abandoned and commercial orchards were not only about equal to standard DDT programs, but their lack of toxicity to the beneficial species should permit increased natural control of infestations of apple mites and perhaps other pests brought on by the use of DDT.