Potential Enhancement of the Gypsy Moth (Lepidoptera: Lymantriidae) Nuclear Polyhedrosis Virus with the Triterpene Azadirachtin

Abstract

Second-instar gypsymoth, Lymantria dispar (L.), larvae were placed on semisynthetic diet and white oak, Quercus alba L., seedlings that had been surface-treated with azadirachtin and gypsy moth nuclear polyhedrosis virus. Both treatments affected larval development (weight gain and molting) and survival. When consumed together, larvae died significantly faster compared with larvae, which consumed only azarurachtin or virus. The combination also resulted in lowered larval survival compared with that observed when only 1 material was consumed. The combination of azadirachtin and virus should result in good foliage protection if used against gypsy moth larvae. However, the addition of azadirachtin to viral formulations could also result in less virus being produced within the larval cadaver and released into the environment because the affected larvae are smaller.