Studies on Ecological Safety of Insecticides to Egg Parasitoids, Trichogramma chilonis Ishii and Trichogramma brasiliensis (Ashmead)

摘要

The adults of the egg parasitoids, Trichogramma chilonis and T. brasiliensis, were exposed to nine different insecticides by glass vial residue method. The results indicated that, lambda-cyhalothrin, bifenthrin and indoxacarb were more toxic to T. chilonis, and the order of toxicity was lambda-cyhalothrin > bifenthrin > indoxacarb > thiamethoxam > carbosulfan, imidacloprid > acetamiprid > pymetrozine > buprofezin. Whereas, T. brasiliensis was more sensitive to carbosulfan and indoxacarb than other insecticides. Carbosulfan and indoxacarb registered 50 % mortality even at 0.001 mg a.i.l(-1). Based on the risk quotient value, which is the ratio between field recommended doses and the LC50 of the parasitoid, lambda-cyhalothrin, carbosulfan and indoxacarb were considered dangerous to T. chilonis. Whereas all other insecticides produced slightly to moderately toxic. In case of T. brasiliensis, thiamethoxam, pymetrozine and buprofezin were found to be slightly to moderately toxic, remaining six insecticides considered dangerous to this parasitoid.