PREBLOOM PETROLEUM OIL APPLICATIONS FOR DELAYING PEAR PSYLLA (HOMOPTERA: PSYLLIDAE) OVIPOSITION

Abstract

AbstractApplication of petroleum oils prior to oviposition by overwintering pear psylla, Psylla pyricola Foerster, reduced oviposition by 98% for up to 5 weeks. The delay of oviposition and reduction in subsequent egg and nymph densities were inversely proportional to the rate of oil used. The reduced oviposition rate was due primarily to inhibition of oviposition by oil deposits on the host, not adult mortality. No commercially important deleterious effects of oil treatments were detected on several pear varieties.