Biological Control of the Coconut Moth, Batrachedra arenosella by Chelonus Parasites in Indonesia

Abstract

An experiment was conducted on the island of Flora, Indonesia, to test for biological control of the coconut moth, Batrachedra arenosella Walker, by introducing the braconid parasite Chelonus sp. Six and twelve months after releasing S gravid females of Chelonus per 4 ha of moth-infested coconuts, the percentage infection of the host pupae, the distribution capacity and the population density of the parasites were determined at 0,50 and 100 m from the point of release. The results of the experiment show that the percentage of parasitized host pupae and population density of the parasite 0 and 50 m from the point of release were approximately twice that found at 100 m. This suggests a slow outward spread of the parasite from its point of introduction. There were only slight increases after 12 months in these parameters and in the percentage of spathes where Chelonus was found when compared with results after 6 months. These results suggest that the parasite has become established but spreads out slowly from its point of introduction. There was only a slight reduction in pest population following release of the parasite during the 12-month period.