Physiological and Genetic Diversity of Cotesia Sesamiae (Cameron)

The role of indigenous natural enemies in suppressing populations of B. fusca and C. partellus has been recognized. One such natural enemy is the larval endoparasitoid Cotesia sesamiae (Cameron). Two biotypes of C. sesamiae have been reported with differential abilities to suppress the immune system of B. fusca. Eggs of a C. sesamiae population from Mombasa were encapsulated while eggs of a population from western Kenya were not. Total and differential haemocytes were counted in larvae of B. fusca at six different times after being exposed to parasitoids from western Kenya, and the eastern coastal area of Kenya. The total number of haemocytes in larvae parasitized by the C. sesamiae population from Mombasa was higher as compared to larvae parasitized by the C. sesamiae population from western Kenya. Fourth-instar B. fusca larvae were treated with calyx fluid from C. sesamiae from western Kenya before offering them to C. sesamiae from the coast for oviposition, and found that the eggs were not encapsulated. The Wolbachia infection of the coastal type did not play a role in the encapsulation response of the host.