BIOLOGICAL AND MICROBIAL CONTROL Potential of Agrotis ipsilon Nucleopolyhedrovirus for Suppression of the Black Cutworm (Lepidoptera: Noctuidae) and Effect of an Optical Brightener on Virus Efficacy

Studieswere performed in the laboratory, greenhouse and Þeld to assess the potential ofAgrotis ipsilonmulticapsid nucleopolyhedrovirus (AgipMNPV) and a viral enhancing agent,M2R, for suppression of Agrotis ipsilon (Hufnagel). In laboratory droplet feeding bioassays, AgipMNPV was shown to be highly active against third-instarA. ipsilon.The optical brightenerM2R signiÞcantly reduced LD50 estimates by 160-fold, but had no direct effect on survival time estimates. In greenhouse trials, spray and bait formulations of AgipMNPV signiÞcantly reduced feeding damage to corn seedlings caused by third-instar A. ipsilon. In two sets of replicated Þeld trials, bait formulations of AgipMNPV signiÞcantly reduced feeding damage to corn seedlings by third-instar A. ipsilon.However, therewere no beneÞcial effects attributable to the inclusion ofM2R inAgipMNPV formulations under greenhouse or Þeld conditions. It seems likely that in an appropriately designed pest management program AgipMNPV could be used to suppress Þeld populations of early and mid-instar A. ipsilon.