DIRECT EFFECTS OF RECOMBINANT NUCLEAR POLYHEDROSIS VIRUSES ON SELECTED NONTARGET ORGANISMS

A limitation to effective field use of naturally occurring nuclear pol yhedrosis viruses (NPVs) is the slow rate at which they kill their hos t. In making NPVs a more attractive pest management tool, this problem has been addressed by modifying NPVs genetically to express insectici dal proteins resulting in substantial increases in their speed of acti on. One concern associated with these recombinant NPVs, however, is th eir effects on nontarget insects associated with pests targeted for co ntrol by applications of NPVs. Our studies evaluated the direct effect s of wild-type Autographa californica NPV (AcNPV) and a recombinant Ac NPV (AcAaIT) on three insects beneficial to production agriculture. Th e recombinant NPV expresses an insect-selective neurotoxin, AaIT, whic h was isolated from tire scorpion, Androctonus australis Hector. Two g eneralist predators, Chrysoperla carnea Stephens and Orius insidiosus (Say), were not adversely affected by feeding on larvae of Heliothis v irescens (F.) infected with AcAaIT. Similarly, no adverse effects were detected in the honey bee, Apis mellifera L., when injected with wild -type or recombinant NPVs. Results from this study may provide a found ation upon which potential risks associated with genetically engineere d NPVs may be evaluated on a limited scale in greenhouse or field expe riments.