RESUMO
Forensic entomology requires knowledge of the developmental rates of the species that colonize a body after death to estimate the postmortem interval (PMI). These developmental rates may vary depending not only on the species but also on the geographic location due to population differences. Therefore, the objectives of this work were to determine the developmental duration of the forensically important fly Chrysomya megacephala under constant controlled and field condition temperatures and to compare these results, through a meta-analysis, with data reported by other authors on populations from different localities. For this, C. megacephala colonies were established in the laboratory, and the duration of the life cycle was studied at two controlled temperatures (25 °C and 27 °C) and field conditions (27.5 ± 3.2 °C). Analysis of variance was performed to determine differences in developmental time and larval length between constant laboratory temperatures and field conditions. A generalized linear model was performed with predictor variables extracted from the literature (diet, relative humidity, latitude, longitude) to evaluate the effect of population variation on developmental times. The results showed significant differences in developmental times between 25 and 27 °C. As expected, the complete life cycle of C. megacephala was shorter at 27 °C. Finally, the meta-analysis suggested differences between the developmental times of different populations, based on temperature and geographic location. The results of this study provide fundamental developmental data to use C. megacephala in PMI estimations. Finally, we suggest that, when making expert reports, information from local populations should be used to determine a more accurate and reliable PMI.
Assuntos
Besouros , Dípteros , Entomologia Forense , Animais , Calliphoridae , Temperatura , Larva , Estágios do Ciclo de VidaRESUMO
A study was carried out to determine Sarcophagidae diversity attracted to the different stages of decomposition of a Boa constrictor cadaver during late winter in the Yucatan Peninsula. As a result of this study, seven species of Sarcophagidae were documented, Oxysarcodexia conclausa (Walker, 1861) (Diptera: Sarcophagidae), Peckia (Euboettcheria) volucris (Wulp, 1895) (Diptera: Sarcophagidae), Blaesoxipha (Gigantotheca) plinthopyga (Wiedemann, 1830) (Diptera: Sarcophagidae), Oxysarcodexia amorosa (Schiner, 1868) (Diptera: Sarcophagidae), Ravinia derelicta (Walker, 1853) (Diptera: Sarcophagidae), Ravinia effrenata (Walker, 1861) (Diptera: Sarcophagidae), and Titanogrypa (Cucullomyia) placida (Aldrich, 1925) (Diptera: Sarcophagidae), The last five species listed are the first documentation of their presence in the Yucatan Peninsula in Mexico. Sarcophagids were present throughout the decomposition process; however, the greatest abundance and diversity of this family were present during the advanced decay stage. This is the first work on flesh flies in the region and the first in the country that has focused on wildlife.