The field studies were conducted to evaluate the bio-efficacy of certain insecticides (spinosad, Indoxacarb, chlorpyriphos, chlorfenapyr and emamectin benzoate) against Thripstabacia, and their chemical compatibility when combination with mancozeb as fungicidesand spray against Thripstabaciaonthe Onion field during 2018season. Physical compatibility of insecticides and mancozeb as fungicides was recorded under the laboratory conditions by taking observations on color, solubility, appearance and pH etc. The results appearance that, spinosad was the superior in reduction percentage infestation with thrips followed by chlorfenapyr, emamectin benzoate, indoxacarb and chlorpyriphos, respectively. The average reduction percentages after spray were 81.5% for spinosad, 72.1% for chlorfenapyr, 66% for emamectin benzoate, 60.1 % for indoxacarb and 55.0 for chlorpyriphos, respectively. The mancozeb addition as fungicides and Tween80 to all tests compounded gave synergism for all insecticide against T.tabacia and Physical compatibility of test insecticide and mancozeb combinations were seen under laboratory conditions. Phytotoxicity symptoms were never observed when insecticides applied alone or their combinations with mancozeb as fungicides on Onion crop compared over control.