Biology of Mylabris impressa stillata (Baudi, 1878) in a Laboratory Colony (Coleoptera: Meloidae)

Abstract

Background: In order to study the biology of Mylabris impressa stillata, which little is known about, a laboratory colony was established.
Methods: In this descriptive study, the laboratory colony was collected from Toyserkan County in Hamedan Province, Iran. To feed the larval instars, a parallel colony of the grasshopper, Schistocerca gregaria was set-up. Meloid females lived for several months and laid egg masses with the intervals of about 2 weeks. The first instar larvae, named triungulin, were heav­ily sclerotized, campodiform, prognathous, and highly mobile. They were fed with fresh eggs of Schistocerca gregaria and the pollen paste. This stage was followed by five FG instars which are weakly sclerotized and hypognathous. After a week of being fed, FG₅ started digging the soil and subsequently was changed to a coarctate larva which characterized by dia­pause.
Results: We succeeded to break such a diapause in laboratory by chilling at 5º C for four months. Thereafter, the larvae moulted to the next step which is called the Second Grub larvae. SG did not feed and was moulted to pupa in the same moist soil. New adults generally rested for three or four days following emergence, their feeding began at the adult age of a week and sexual behaviour normally appeared at a mean age of about 10 days. The complete life cycle of Mylabris impressa took about nine months.
Conclusion: Laboratory rearing of blister beetles remains the best tool for ecological and chemical research as well as nup­tial gift studies, but very labour intensive and time consuming with low yield.