TRANSMISSION OF NUCLEAR POLYHEDROSIS-VIRUS BY THE PARASITOID MICROPLITIS CROCEIPES (HYMENOPTERA, BRACONIDAE) TO HILIOTHIS VIRESCENS (LEPIDOPTERA, NOCTUIDAE) ON SOYBEAN

Transmission of Heliothis nuclear polyhedrosis virus (NPV) by the parasitoid Microplitis croceipes (Cresson) to Heliothis virescens (F.) larvae was examined. Mortality from NPV occurred in larvae exposed to Heliothis NPV-contaminated female parasitoids in the laboratory and on soybean in the field. In single-plant and large-cage field tests, mortality from Heliothis NPV in larvae exposed to virus-contaminated parasitoids was higher when the parasitoid's entire body surface had been artificially contaminated with virus than when only the parasitoid's ovipositor and surrounding area were artificially contaminated or when the parasitoid was previously allowed to oviposit in Heliothis NPV-infected larvae. The level of mortality from Heliothis NPV in caged larvae also increased as the parasitoid density in the cage increased from 0.25 to 3.0 per meter of row. © 1990 Entomological Society of America.