Lethal and sublethal effects of insecticide residues on Orius insidiosus (Hemiptera : anthocoridae) and Geocoris punctipes (Hemiptera : lygaeidae)

Laboratory-reared predators, the insidious flower bug, Orius insidiosus (Sa y), and big-eyed bug Geocoris punctipes (Say), were exposed to 10 insectici des, including three newer insecticides with novel modes of action. using a residual insecticide bioassay. These species are important predators of se veral economic pests of cotton. Insecticides tested were: azinphos-methyl, imidacloprid, spinosad, tebufenozide, fipronil, endosulfan, chlorfenapyr, c yfluthrin, profenofos, and malathion. There was considerable variation in r esponse between both species tested to i insecticides. Tebufenozide and cyf luthrin were significantly less toxic to male O. insidiosus than malathion. Tebufenozide was also significantly less toxic to female O. insidiosus tha n malathion, tebufenozide, and spinosad were significantly less toxic to ma le G. punctipes than chlorfenapyr, endosulfan, and fipronil. Spinosad, tebu fenozide, and azinphos-methyl were significantly less toxic to female G. pu nctipesper than fipronil and endosulfan. Fecundity of O. insidiosus was sig nificantly greater in the spinosad treatment compared with other treatments including the control. Consumption of bollworm, Helicoverpa zea (Boddie), eggs by O. insidiosus was significantly lower in the fipronil, profenofos, and cyfluthrin treatments compared with other treatments including the cont rol. Consumption of II. zea eggs by G. punctipes was significantly lower in the malathion, profenofos, endosulfan, fipronil, azinphos-methyl, and imid acloprid treatments compared with the control. Egg consumption by G. puncti pes was not significantly different in the tebufenozide treatment compared with the control. The lower toxicity of spinosad to C. punctipes is consist ent with other reports. Based on these results, the following insecticides are not compatible with integrated pest management of cotton pasts: malathi on, endosulfan, profenofos, fipronil, and cyfluthrin; while imidacloprid, t ebufenozide, azinphos-methyl, and spinosad should provide pest control whil e sparing beneficial species.