Toxicidade de natuneem sobre Tetranychus urticae Koch (Acari: Tetranychidae) e ácaros predadores da família Phytoseiidae

Abstract

The toxicity of the Natuneem at different concentrations for both Tetranychus urticae Koch and two predatory mites Euseius alatus De Leon and Phytoseiulus macropilis (Banks) were studied. The toxicity on eggs, and the residual and repellent effects on adults was evaluated. Egg treatment consisted on dipping eggs into Natuneem dilutions for five seconds; and residual and repellent effects for adults consisted on dipping leaf discs of Canavalia ensiformes (L.) DC. into the dilutions for five seconds. Natuneem was repellent for T. urticae and E. alatus at the concentrations 0.25, 0.50 and 1.0%, and exhibited neutral effect on P. macropilis. The toxicity of Natuneem on eggs and adults was greater for T. urticae compared to the toxicity on predatory mites. The fecundity of T. urticae was reduced significantly by Natuneem in all concentration. On predatory mites significant reduction on its fecundity was found at the highest concentrations evaluated. Natuneem was performed better against the twospotted spider mite and exhibited relatively low impact against the predatory mites under the conditions studied.