The bionomics of the egg parasitoid Telenomus busseolae (Gahan) (Hymenoptera: Scelionidae) on Busseola fusca Fuller and Sesamia calamistis Hampson (Lepidoptera: Noctuidae) in Kenya.

摘要

The suitability of 1-3-day-old eggs of Busseola fusca Fuller and Sesamia calamistis Hampson (Lepidoptera: Noctuidae) to a strain of Telenomus busseolae (Gahan) (Hymenoptera: Scelionidae) collected in mid-altitudes of Kenya was assessed in the laboratory. For both species, age of egg did not affect progeny production but two-day-old B. fusca eggs yielded more progeny than S. calamistis eggs of the same age. With S. calamistis, development time of T. busseolae increased with age of eggs, while host species had no effect. Neither borer species nor age of eggs significantly affected the sex ratio. Longevity of T. busseolae was greater and total fecundity higher on B. fusca than S. calamistis. The intrinsic rate of increase and the net reproductive rate were greater with B. fusca than S. calamistis eggs as host. The values were considerably lower than those reported from the same species in West Africa, indicating that there are differences in strains between regions. Females began ovipositing on the first day of emergence and the average daily number of eggs laid and the proportion of females decreased with age of the female, on both hosts. The ability of T. busseolae females to accept and develop in B. fusca and S. calamistis of different ages is an advantage, especially during times of host scarcity, which is common during the dry-season. In a Y-tube experiment no preference for either stemborer species was observed. Similarly, in the field, there was no significant variation in parasitism between B. fusca and S. calamistis eggs..