Developmental Times of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) at Constant Temperatures and Applications in Forensic Entomology

The characteristic life stages of infesting blowflies (Calliphoridae) such as Chrysomya megacephala (Fabricius) are powerful evidence for estimating the death time of a corpse, but an established reference of developmental times for local blowfly species is required. We determined the developmental rates of C. megacephala from southwest China at seven constant temperatures (16-34 degrees C). Isomegalen and isomorphen diagrams were constructed based on the larval length and time for each developmental event (first ecdysis, second ecdysis, wandering, pupariation, and eclosion), at each temperature. A thermal summation model was constructed by estimating the developmental threshold temperature D-0 and the thermal summation constant K. The thermal summation model indicated that, for complete development from egg hatching to eclosion, D-0 = 9.07 +/- 0.54 degrees C and K = 3991.07 +/- 187.26 h degrees C. This reference can increase the accuracy of estimations of postmortem intervals in China by predicting the growth of C. megacephala.