Overview

Establishment of Cotesia flavipes Cameron, a braconid parasitoid of Chilo partellus Swinhoe (Lepidoptera: Crambidae) was monitored in the cropping season of 2002 and 2003 in Masindi and Kumi districts. Establishment was determined by sampling maize and sorghum fields where C. flavipes had previously been released in 1997. Ten farmers’ fields were sampled in each district. The rate of parasitism of Cotesia sesamia Cameron and of C. flavipes varied according to stemborer species and location. A high rate of host specificity was observed in the two districts with each parasitoid species exhibiting preference for the coevolved host, suggesting probable absence of interspecific competition. Cotesia flavipes was established in

Kumi but not in Masindi. There is need for diversification of biological control strategies in Masindi to supplement the activities of the indigenous parasitoids. Such strategies could include redistribution of African parasitoids and introduction of more effective parasitoids.