Cross Mating Studies in Epilachna vigintioctopunctata Fab. (Coleoptera: Coccinellidae) From Three Regions of Bangladesh

Single-pair cross mating schedules in Epilachna vigintioctopunctata from three regions of Bangladesh namely Khulna (KHU), Rajshahi (RAJ) and Sylhet (SYL) revealed significant differences for fecundity (P<0.01), number of pupae formed, number of adults emerged and female ratio (P<0.05) in the beetles, while the differences for egg-hatch (%) and larval duration (days) were not significant. All the crosses were compatible, though the egg-hatch was the lowest in SYL female × RAJ male than other crosses, and deformed adults in low frequencies (0.07-0.29) were recorded from the regional reciprocal crosses only. It is therefore postulated that either the distance between the regions are not significant or insects are not isolated enough for inducing incompatibility in the beetles under study.