Field Evaluation of Goniozus nephantidis (Muesebeck) against Coconut Black-Headed Caterpillar in Kerala Using Different Release Techniques

Many entomophagous insects attack the black-headed caterpillar of coconut, Opisina arenosella Walker during its developmental stages. Goniozus nephantidis (Muesebeck) is a gregarious larval parasitoid of O. arenosella. During summer months of 2003-04 and 2004-05 the parasitoid was evaluated in the field in Kerala by following two methods - trunk and crown release that were compared with control. There was significant reduction in the population of O. arenosella after third to sixth releases in treated palms, when compared to control palms. There was no significant difference between the two methods of release of G. nephantidis in reducing the population of O. arenosella. Hence farmers could easily and effectively adopt the trunk release method.