Effects of some insecticides on guava cottony scale, Capulinia sp. (Hemiptera: eriococcidae)

During Jan-Mar 2004 and Jun-Jul 2005, two experiments were conducted in order to evaluate the effect of some insecticides on Capulinia sp. The treatments included in the first experiment, carried out in the laboratory, were chlorpyrifos (0.06% v/v a.i.), imidacloprid (0.06% p/v a.i.), azadiractin (0.45% p/v a.i.), Bauveria bassiana (2X10 super(12) conidia/100g, 2.5g/l) and an untreated control. The insecticide mixtures contained a surfactant (Extravon 200 0.5% v/v). In the second experiment, conducted outside the laboratory, an additional treatment consisting of surfactant+water only, was included The numbers of live and dead individuals were counted previous to the application of treatments and at 48, 72, 96h post application, followed by six and seven weekly counts for the first and second experiments, respectively. Mortality (%) was higher under chlorpyrifos and imidacloprid, where all the treated plants reached the end of the test in good conditions, contrasting with the other treatments, where insect-caused stem necrosis occurred. Although the effectiveness of these two insecticides is shown, their usage should be considered within the rationality of integrated pest management.