Insecticidal effects of an insect-specific neurotoxin expressed by a recombinant baculovirus.

The scorpion Androctonus australis has a peptide (AaIT) which selectively targets the insect sodium channel. This mode of action is similar to that of many widely used chemical insecticides. When Bombyx mori larvae were infected with a recombinant baculovirus carrying a synthetic AaIT gene, the expressed protein was secreted into the hemolymph and caused symptoms consistent with sodium channel blocking, including tremors and feeding cessation at 40 hr p.i. followed by paralysis and death by 60 hr p.i. Larvae infected with control virus died by 96 hr p.i. These results indicate that foreign genes can be used in recombinant baculoviruses to reduce insect feeding damage and increase the rate of insect kill.