Effects of population variations and temperature on Chrysomya megacephala (Diptera: Calliphoridae) development: implications for estimating the postmortem interval

ANA JULIA PEREIRA; NÉSTOR D. CENTENO; CAROLINA NUÑEZ-VÁZQUEZ

INTERNATIONAL JOURNAL OF LEGAL MEDICINE.

SPRINGER

Lugar: Berlin; Año: 2023

0937-9827

Forensic entomology requires knowledge of the developmental rates of the species that colonize abody after death to estimate the postmortem interval (PMI). These developmental rates may varydepending not only on the species but also on the geographic location due to populationdifferences. Therefore, the objectives of this work were to determine the developmental duration ofthe forensically important fly Chrysomya megacephala under constant controlled and fieldcondition temperatures, and to compare these results, through a meta-analysis, with data reportedby other authors on populations from different localities. For this, C. megacephala colonies wereestablished in the laboratory, and the duration of the life cycle was studied at two controlledtemperatures (25°C and 27°C) and field conditions (27.5 ± 3.2°C). Analysis of variance wasperformed to determine differences in developmental time and larval length between constantlaboratory temperatures and field conditions. A GLM was performed with predictor variablesextracted from the literature (diet, relative humidity, latitude, longitude) to evaluate the effect ofpopulation variation on developmental times. The results showed significant differences indevelopmental times between 25°C and 27°C. As expected, the complete life cycle of C.megacephala was shorter at 27°C. Finally, the meta-analysis suggested differences between thedevelopmental times of different populations, based on temperature and geographic location. Theresults of this study provide fundamental developmental data to use C. megacephala in PMIestimations. Finally, we suggest that, when making expert reports, information from localpopulations should be used to determine a more accurate and reliable PMI.