Quality changes in successive generations of the millet stem borer, Coniesta ignefusalis (Hampson) (Lepidoptera : Pyralidae), in northern Ghana

Studies were conducted in northern Ghana in 1996 and 1997 to assess any cha nges in the quality of insects in different generations of the millet stem borer, Coniesta ignefusalis (Hampson), over the growing season. The goal wa s to determine if, and to what extent, such changes are responsible for obs erved differences in the sizes of populations of successive generations of the insect. Pupae from diapause larvae gave rise to adults that were signif icantly smaller and had lower reproductive rates than those derived from no n-diapause larvae. There were, however, no significant differences between the non-diapause generations for all the quality indicators studied. The re sults suggest that observed differences in the sizes of generations develop ing from non-diapause and diapause larvae of C. ignefusalis are, at least, partly due to differences in the inherent quality of individuals of these g enerations.