Seletividade de inseticidas utilizados no meloeiro sobre Chrysoperla genanigra Freitas e Chrysoperla externa HAGEN (Neuroptera: Chrysopidae).

Abstract

For predators of pest insects are used in melon cultivation, associated with pesticides, it is necessary that those products are selective to natural enemies. In this sense, the aim of this study was to evaluate the toxic effects of some insecticides used in melon cultivation to control pests on eggs of Chrysoperla genanigra and larvae of Chrysoperla externa, also analyzing the effects on the subsequent phases of the development of contaminated predators stages. The tests were developed in the Laboratory of Selectivity of Plant Protection Products Sector of the Plant Protection Department of Plant Sciences, Federal Rural University of the Semi-Arid. The experiments were performed according to the standard methodology of the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). Products tested with their respective strengths (assets g / L igrediente water) were Chlothianidin (0.1), Pymetrozine (0.25), Lambda-cyhalothrin (0.025), Clorantraniliprole (0.0025), Indoxacarb (0.036 ), pyriproxyfen (0.1), Beta-cyfluthrin / Imidacloprid (0.0625 +0.5), Imidacloprid (1.05) and Beta-Cypermethrin (0.04), the control was only composed of distilled water. The applications of the products were performed manually pressurized spray. In the first experiment insecticide applications were made on the egg genanigra C. in Petri dishes were then individually in glass tubes of 2.0 cm diameter by 8.0 cm tall sealed in its upper part with plastic film of polyvinyl chloride (PVC) and kept under controlled environmental conditions at 25 ± 2 º C, 70 ± 10% UR and 12h photophase. The parameters evaluated were the duration and survival of the immature stage, the sex ratio of adults from treated eggs as well as the total average oviposition / female in the study period and egg viability of the progeny. In the second experiment the treatments were indirect larvae of C. externa, on a Petri dish with subsequent release of larvae, continuing in the footsteps of the first experiment. We assessed duration and survival of the immature stage, the sex ratio of adults from treated eggs as well as the total average oviposition / female in the study period and egg viability of the progeny. Lambdacyhalothrin, indoxacarb and Pymetrozine Imidacloprid were selective for the species C. genanigra, while clothianidin, beta-cypermethrin, beta-cyfluthrin / Imidacloprid, Pyriproxyfen and Clorantraniliprole were toxic for this species. For larvae of C. externa, and the Pymetrozine Clorantraniliprole insecticides were harmless, whereas clothianidin, Lambda-cyhalothrin, indoxacarb pyriproxyfen, Beta-ciflutina / Imidacloprid, Imidacloprid and Beta-cypermethrin proved toxic.