Life Cycle and Biometric Study of Hydrotaea capensis (Wiedemann, 1818) (Diptera, Muscidae), a Species of Forensic Interest

Abstract

Simple SummaryFrom the point of view of forensic entomology, the study of the development times of the species and the factors conditioning them are issues of great importance to estimate the minPMI. Hydrotaea capensis is a Muscidae (Diptera) of forensic interest because of its colonization preferences. Thus, there is a need to have more precise data about its biology to gain insights into the interpretation of its presence in corpses. In this study, the H. capensis life cycle was studied at four constant temperatures, 18, 20, 25 and 30 °C, by recording the duration of its different developmental stages and the length reached in each larval stage, as well as some biometric characteristics of the emerged adults. Our work is the first to provide data on the duration of the life cycle of this species and pointed to some alar features as relevant biometric adult indicators to be considered.One of the most important and perhaps most used applications of forensic entomology concerns the estimation of the minimum post-mortem interval (minPMI), defined as the time interval between death and the actual finding of a corpse. Some Diptera species are critical in these studies because they are the first ones capable of detecting and finding a corpse and are selectively attracted by its decomposing status. Thus, the knowledge of the micromorphology of their preimaginal stages and of their life cycles within a time frame constitutes solid indicators for estimating the minPMI. Hydrotaea capensis is a Muscidae of forensic interest usually considered as a late colonizer of corpses. It is widely distributed, living mainly in warm regions, and present in a wide variety of habitats. In this study, the H. capensis life cycle was studied at four constant temperatures, 18°, 20°, 25° and 30 °C, by recording the duration of its different developmental stages, including the length reached in each larval stage, as well as some biometric characteristics of the emerged adults. Significant differences were observed in the average time of development of most larval stages, with a longer duration at low temperatures, and in the length of each larval stage depending on the temperature, but, in this case, without a clear pattern. Moreover, significant differences were found in some alar features, pointing to them as a relevant indicator to be considered. The data provided will assist forensic entomologists to make more accurate minPMI estimations in cases where H. capensis is present.