Biochemical and Histological Effects of Lambda Cyhalothrin, Emamectin Benzoate and Indoxacarb on German Cockroach, Blattella germanica L.

Background and Objective: German cockroach developed its high resistance to insecticide groups very fast, therefore, this study conducted to evaluate spinosad, indoxacarb, lambda cyhalothrin and emamectin benzoate as safe insecticides.Materials and Methods: A filter paper contact toxicity bioassay method was used to evaluate the toxicity of the three insecticides on German cockroach.The effect of LC 30 and LC 50 of insecticides on some enzymes activity had determined.The histological effects were determined using LC 30 of tested insecticides.Results: The indoxacarb was the most toxic insecticide.The activity of Ach E activity decreased after treated with LC 30 and LC 50 of the tested insecticides.Higher increase in " esterase activity was achieved after treating with LC 30 and LC 50 of indoxacarb and emamectin benzoate, while $ esterase was decreased after treated with LC 30 of the tested insecticides.The total protein, carbohydrate and lipid contents were decreased after treating with LC 30 and LC 50 of the tested insecticides.Three tested insecticides caused noticeable histopathological signs.Conclusion: The tested pesticides showed high toxicity to the German cockroach and indoxacarb was the most toxic, also significant biochemical and histological effects were recorded.