EFFECTS OF NEEM OIL ON FEEDING-BEHAVIOR AND DEVELOPMENT OF THE PEAR SAWFLY, CALIROA-CERASI

Neem oil deterred feeding by pear sawfly, Caliroa cerasi L., larvae (H ymenoptera: Tenthredinidae), both in choice and in no-choice cherry le af disk bioassays. Deterrence was greater in the choice tests, with 50 % inhibition occurring al 0.49% aqueous neem oil compared with 1.11% i n the no-choice tests. Antifeedant activity towards pear sawfly larvae is slightly less than has been observed for Lepidoptera, but is highe r than deterrence to other insects such as aphids. Topical application of neem oil to sawfly larvae resulted in reduced feeding, increased m ortality, and a trend towards slower development. Most larval mortalit y after neem treatment resulted from incomplete subsequent moults. The potential utilization of neem insecticides for control of pear sawfly in tree fruit pest management is discussed.