Comparative evaluation of Cotesia flavipes and C-sesamiae (Hymenoptera : Braconidae) for the management of Chilo partellus (Lepidoptera : Pyralidae) in Kenya

Cotesia flavipes Cameron, a gregarious larval endoparasitoid native to the Indo-Australian region, was imported from Pakistan and released in Kenya in 1993 for management of the exotic stemborer, Chile partellus (Swinhoe). Re cent reports confirmed the successful establishment of the parasitoid in th ree locations in Kenya and in northern Tanzania. Functional response studie s on this parasitoid and an indigenous congener, Cotesia sesamiae (Cameron) , indicated that C. flavipes had a higher searching ability and attacked mo re larvae when Chile partellus was the host. When a native stemborer, Sesam ia calamistis Hampson, was the host, there was no significant difference be tween numbers attacked by both parasitoids. Numerical response studies show ed that Cotesia flavipes produced more total progeny and female progeny per female parasitoid on Chile partellus than did Cotesia sesamiae. No signifi cant difference in progeny production was detected between the two parasito ids on S. calamistis. Functional and numerical responses tested in the labo ratory gave the same ranking of the two parasitoids on the two hosts as in the field. This study suggests that Cotesia flavipes is a more efficient pa rasitoid and it is anticipated that it will contribute to the control of bo th exotic and native stemborers in Kenya.