Investigating the Influence of Conspecific and Heterospecific Factors on the Development of Blowflies Calliphora vicina and Phormia regina to Estimate PMI in Islamabad Across Seasonal Variations

Abstract

The accurate determination of Postmortem Interval (PMI) is crucial in forensic investigations to establish the time of death and aid in solving criminal cases. Blowflies (Diptera: Calliphoridae) have been widely utilized as indicators for PMI estimation due to their reliable colonization of decomposing remains. This research explores into the intricate dynamics of blowflies Calliphora vicina and Phormia regina, two prevalent species in Islamabad's ecosystem, to unravel the interplay between conspecific and heterospecific factors affecting their developmental timelines. Employing meticulous morphometric identification facilitated by a stereo microscope, the study successfully classified the specimens as Calliphora vicina and Phormia regina. Subsequent experiments involved the rearing of these species individually as well as in mixed settings within controlled environments. By meticulously tracking the developmental stages of larvae and pupae, a comprehensive analysis of the developmental timeframes was achieved, allowing insight into the intricate growth patterns. This comprehensive investigation was conducted across multiple seasons—summer, winter, spring, and autumn—to account for the potential impact of seasonal variations on blowfly development. The results shed light on the distinct rates of development influenced by both species interactions and changing climatic conditions. This innovative research, carried out within the premises of Quaid-i-Azam University, Islamabad, contributes invaluable knowledge to the realm of forensic entomology, enhancing our ability to estimate PMI accurately across diverse seasonal variations.