EFFECT OF INSECTICIDES ON THE NATURAL INF ECTION OF VELVETBEAN CATERPILLAR BY NOMURAEA-RILEYI

The entomopathogenic fungus Nomuraea rileyi is an important natural bi ological control agent for Anticarsia gemmatalis Hubner population at the West Central Region, in Brazil. The objective of the current study was to examine the influence of nine insecticides on the natural infe ction of A. gemmatalis by the entomogenous fungus N. rileyi, during tw o consecutive years in Senador Canedo, Colas, Brazil, using the insect icides recommended commercial dosages. The experimental design was a r andomized complete block with ten treatments and four replications. Th e effect of trichlorfon and chlorpyriphos ethyl did not differ from th e untreated check. Baculovirus anticarsia, diflubenzuron, endosulfan, methamidophos, monocrothophos, methyl parathion and thiodicarb had sim ilar performance and caused a significant decrease on the percentage o f infected larvae.