Toxicity Determination of Some Insecticides Against Trichogramma chilonis Ishii

The screening of some insecticides viz. monocrotophos, chlorpyriphos, cypermethrin and imidacloprid was done to determine the LC₅₀ values against Trichogramma chilonis. Imidacloprid was found most toxic to Trichogramma chilonis, at thirty minute, one, two and six hour after treatment with their lowest LC₅₀ value of 0.07, 0.03, 0.075, and 0.00004 per cent respectively followed by cypermethrin. While, chlorpyriphos and monocrotophos was found least toxic to the T. chilonis with its higher LC₅₀ value. Thus, the monocrotophos and chlorpyriphos can be safely used in field application with T. chilonis in I.P.M. programme. While, imidacloprid should be avoided or used in alternatively with T. chilonis under strict supervision in field application.