Integrated Control of the Tomato Fruitworm (Lepidoptera: Noctuidae) and Other Lepidopterous Pests on Fresh-Market Tomatoes in Southern California1

Abstract

Studies were conducted toward the development of an integrated control program for the tomato fruitworm and other lepidopterous pests on summer plantings of fresh-market tomatoes in southern Califomia in 1978 and 1979. An integrated pest management (IPM) program, which consisted of weekly applications of Dipel ( Bacillus thuringiensis Berliner var. kurstaki ) plus twice-weekly releases of Trichogramma pretiosum Riley, was compared with weekly applications of methomyl (commercial program). The effect of the two programs on the vegetable leafminer, predators, and egg parasitization also was noted. Mean total fruit injured by all lepidopterous pests was 0.7, 1.6, and 7.1% in the commercial, IPM, and untreated control plots, respectively, in 1978, and 0.3, 0.9, and 5.3% in 1979. These differences were significant ( P < 0.05) both years. There were no significant differences in fruit yield or size between the two treatment programs in either year. Methomyl adversely affected predator populations, host eggs, and egg parasitization by T. pretiosum , whereas Dipel did not. Methomyl also significantly increased vegetable leafminer populations, whereas Dipel did not. The effect of methomyl on host eggs (ovicidal) and T. pretiosum was restricted primarily to those present at time of application.