Effect of juvenoids pyriproxyfen and diofenolan on embryogenesis and postembryonic development of blow fly Chrysomya megacephala (Diptera: Calliphoridae) following egg treatment.

The blow fly Chrysomya megacephala is a serious medico-veterinary pest causing myiasis in humans and animals apart from transmitting various disease-causing pathogens. Being an economically important pest, it warrants successful control in the early stages without affecting the host, environment, and non-target organisms. Juvenoids being safe, species and stage selective, biodegradable, and harmless to beneficial non-target organisms. Treatment of freshly laid eggs of C. megacephala with juvenoids pyriproxyfen and diofenolan (50 and 100 μg/cm(2)) by contact method for 1-60 min severely derailed the embryogenesis and postembryonic development. The results included the following: reduced eclosion, dead, non-viable eggs, undeveloped embryos of various stages, and fully developed embryos entrapped in chorion and unable to eclose. Several latent effects of juvenoids were also observed like larval mortality in the first instar, abnormal pupariation, reduced normal pupariation, formation of pupal-adult mosaics, suppression of adult emergence, and emergence of only deformed adults. Diofenolan was found to be more potent than pyriproxyfen in suppressing embryogenesis. These results show that the juvenoids pyriproxyfen and diofenolan have the potential to be judiciously used along with other bio-rational methods for the successful control of C. megacephala.