Effects of dicofol on survivorship and oviposition of Colorado potato beetle (Coleoptera: Chrysomelidae) and on field plant protection

Laboratory and field experiments were conducted to determine the potential importance of dicofol in the management of Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say). Laboratory experiments determined the effects of dicofol-treated (0.37 and 0.55 g [AI]/liter) and nontreated potato, Solanum tuberosum tuberosum L. cv. Pungo, foliage on survivorship and egg mass production of CPB. Corresponding field experiments determined the effects of dicofol on abundance and damage of CPB and subsequent yield of potato. Survivorship and egg mass production of CPB were significantly lower on dicofol-treated than on nontreated foliage. Females produced 0.55 +/- 0.03 egg masses per female per day on nontreated foliage compawith zero or nearly zero egg masses per female per day on foliage treated with 0.37 and 0.55 g (AI)/liter of dicofol, respectively. In the field, abundance and damage of CPB were significantly lower on dicofol-treated plants than on nontreated plants. Tuber yields of dicofol-treated plants were 3.4-5.9 times greater than those of nontreated plants, comparable to those of plants treated with the current insecticide standard for CPB management in New Jersey. The potential of dicofol in CPB management programs is discussed