FIELD-EVALUATION OF STEINERNEMA-CARPOCAPSAE (WEISER) (RHABDITIDA, STEINERNEMATIDAE) AND SELECTED PESTICIDES AND ENHANCERS FOR CONTROL OF PHYLLOCNISTIS CITRELLA STAINTON (LEPIDOPTERA, GRACILLARIIDAE)

The efficacies of sprays containing the entomopathogenic nematode Stei nernema carpocapsae and selected pesticides and enhancers for control of citrus leafminer, Phyllocnistis citrella, were evaluated in two exp eriments. The first compared three rates of nematode infective juvenil es plus a nonionic surfactant with three rates of petroleum spray oil, three rates of fenoxycarb, and single rates of methidathion and perme thrin. The second compared three rates of infective juveniles plus non ionic surfactant with the same three rates of infective juveniles plus a polysaccharide and petroleum spray oil mixture, three rates of feno xycarb plus petroleum spray oil, and single rates of methidathion and fenoxycarb. Larval mortalities caused by methidathion, permethrin, the highest race of the nematode, and the two higher rates of fenoxycarb in the first experiment were all significantly higher than the control , with permethrin the most effective treatment. The effect of oil on m ortality was ambiguous, and the percentage of mined leaves in all spra yed treatments did not differ significantly from the control. In the s econd experiment larval mortalities were only significantly higher tha n in the control in the fenoxycarb and methidathion treatments. Howeve r, with the exception of the nematode/surfactant and methidathion trea tments, the number of mines per leaf in all sprayed treatments was sig nificantly lower than in the control. Similar differences were recorde d for percentage of mined leaves. In the nematode/polysaccharide/oil t reatments these effects were not related to nematode concentration ind icating a controlling effect of the polysaccharide/oil mixture warrant ing further investigation. We believe these effects on infestation lev els were more important than any effect on larval mortality.