Seletividade de produtos fitossanitários visando à conservação de Trichogramma galloi (Zucchi, 1988) (Hymenoptera: Trichogrammatidae) na cultura da cana-de-açúcar

Abstract

In this work, it was studied the repellency and toxicity of insecticides chlorantraniliprole (350g/kg), ethiprole (200 g/l), thiamethoxam (250 g/kg), triflumuron (480 g/l), lambda-cyhalothrin+thiamethoxam (106 g/l + 141 g/l), fipronil (800 g/kg) and Metarhizium anisopliae (50 g/kg); the herbicides chlomazone (800 g/l) and diuron+hexazinone (488 g/kg + 142 g/kg) and the plant growth regulators sulfometuron-methyl (750 g/kg) and trinexapac-ethyl (250 g/l), in adult and immature of Trichogramma galloi, in eggs of Diatraea saccharalis. The products evaluated were in the highest concentrations recommended for the cultivation of cane sugar, following the method recommended by the "IOBC". To evaluate the repellency of each product, testing was conducted with free-choice, where 30 eggs of D. saccharalis were immersed in distilled water and another 30 in the product to be tested. These egg masses were transferred to distinct glasses tube, which were connected by a roll of paper with a central hole through which a small tube with three females of T. galloi was engaged. Were evaluated the parasitism and the emergence of the parasitoid, it was considered repellency when in the witness was found a number of parasitized eggs greater than the products. To evaluate the effects of pesticides on the adult of T. galloi 60 eggs of D. saccharalis were treated by immersion in chemicals grout and after drying, offered to females of T. galloi. It was evaluated the mortality and the number of parasitized eggs of the F0 and F1 emergence. The effects on immature stage of T. galloi were evaluated by immersion of eggs of D. saccharalis containing the parasitoid on stages of egg-larva, pre-pupa and pupa, analyzing the effects on emergence of the F1 T. galloi, as well as the number of parasitized eggs and the emergence of the F2 generation. Chlorantraniliprole, triflumuron, fipronil and sulfometuron-methyl not repelled T. galloi. About the parasitoid adults, chlorantraniliprole, M. anisopliae, clomazone, diuron+hexazinone, trinexapac-ethyl and sulfometuron-methyl did not affect survival, number of parasitized eggs and the emergence of T. galloi. However, for the parasitoid immature stages, it was observed that clomazone, diuron+hexazinone and sulfometuron-methyl did not affect the F1 and F2 of T. galloi, for chlorantraniliprole, M. anisopliae, and etiprole trinexapac-ethyl it was not observed effect on the F1, however, reduced the number of eggs parasitized by F2.