Direct and Indirect Effects of Pesticides on the Insidious Flower Bug (Hemiptera: Anthocoridae) Under Laboratory Conditions

Greenhouse producers are interested in integrating natural enemies along with pesticides to suppress western flower thrips, Frankliniella occidentalis (Pergande), populations. The insidious flower bug, Orius insidiosus (Say), is a commercially available natural enemy of western flower thrips. We conducted a series of laboratory experiments to determine the direct and indirect effects of 28 pesticides (insecticides, miticides, and fungicides), 4 pesticide mixtures, and 4 surfactants (36 total treatments plus a water control) on the adult O. insidiosus survival and predation on western flower thrips adults under laboratory conditions. The number of live and dead O. insidiosus adults was recorded after 24, 48, 72, and 96 h. The results of the study indicate that the fungicides (aluminum tris, azoxystrobin, fenhexamid, and kresoxim-methyl), insect growth regulators (azadirachtin, buprofezin, kinoprene, and pyriproxyfen), botanicals (Capsicum oleoresin extract, garlic oil, soybean oil; and rosemary, rosemary oil, peppermint oil, and cottonseed oil), and entomopathogenic fungi (Beauveria bassiana and Metarhizium anisopliae) were minimally directly harmful to adult O. insidiosus, with 80% to 100% adult survival. However, abamectin, spinosad, pyridalyl, chlorfenapyr, tau-fluvalinate, imidacloprid, dinotefuran, acetamiprid, and thiamethoxam directly affected O. insidiosus survival after 96 h (0-60% adult survival). The pesticide mixtures of abamectin + spinosad and chlorfenapyr + dinotefuran reduced adult survival (20% and 0%, respectively, after 48 h). Furthermore, the surfactants were not directly harmful to O. insidiosus adults. All western flower thrips adults were killed by the surviving adult O. insidiosus after 48 h, indicating no indirect effects of the pesticides on predation.