Assessment of Gaucho (R) seed treatment effects on beneficial insect abundance in sorghum

Numbers of beneficial insects in sorghum, Sorghum bicolor (L.) Moench, trea ted with Gaucho(R) 480FS (imidacloprid, Gustafson LLC) to control greenbug, Schizaphis graminum (Rondani), were compared to untreated sorghum in the T exas Southern Rolling Plains (San Angelo). Widespread use of this seed trea tment, if detrimental to natural enemies, could adversely affect late-seaso n pest control by natural enemies in sorghum and mid- to late-season pest c ontrol in adjacent cotton. Weekly visual inspections of 50 plants in each f ield found early season Hippodamia convergens Guerin numbers followed the s ame trend as that of corn leaf aphids, Rhopalosiphum maidis (Fitch), with s ignificant differences occurring 30 and 37 d after planting, but no differe nces were found at later dates. No significant differences were found for a ny of the other main predators collected by beat-bucket in late-season, sug gesting the lack of any significant long-term detrimental effects from Gauc ho(R) seed treatment on late-season abundance of natural enemies in sorghum .