Field Evaluation of Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae) and Selected Pesticides and Enhancers for Control of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae)

Abstract

The efficacies of sprays containing the entomopathogenic nematode Steinernema carpocapsae and selected pesticides and enhancers for control of citrus leafminer, Phyllocnistis citrella, were evaluated in two experiments. the first compared three rates of nematode infective juveniles a plus nonionic surfactant with three rates of petroleum spray oil, three rates of fenoxycarb, and single rates of methidathion and permethrin. the second compared three rates of infective juveniles plus nonionic surfactant with the same three rates of infective juveniles plus a polysaccharide and petroleum spray oil mixture, three rates of fenoxycarb plus petroleum spray oil, and single rates of methidathion and fenoxycarb. Larval mortalities caused by methidathion, permethrin, the highest rate 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 mortality was ambiguous, and the percentage of mined leaves in all sprayed treatments did not differ significantly from the control. In the second experiment larval mortalities were only significantly higher than in the control in the fenoxycarb and methidathion treatments. However, with the exception of the nematode/surfactant and methidathion treatments, the number of mines per leaf in all sprayed treatments was significantly lower than in the control. Similar differences were recorded for percentage of mined leaves. In the nematode/polysaccharide/oil treatments these effects were not related to nematode concentration indicating a controlling effect of the polysaccharide/oil mixture warranting further investigation. We believe these effects on infestation levels were more important than any effect on larval mortality. Copyright © 1995, Wiley Blackwell. All rights reserved