A forensic perspective on geographical and temperature-driven differences in the development of Lucilia sericata (Meigen, 1826)

Abstract

The age of the oldest immature insects present on a cadaver is typically used by forensic entomologists to estimate the minimum postmortem interval (PMI_min). The green bottle fly, Lucilia sericata (Meigen, 1826), known for its widespread distribution and necrophagy, is of considerable significance in forensic science. This study aimed to investigate potential regional developmental disparities between populations of L. sericata in China and to identify the origins of such variances. Developmental data of L. sericata populations from Shandong, Jiangsu, and Ningxia in China were analyzed under seven constant temperatures ranging from 16-34 °C, including developmental duration, pupal length, and thermobiological parameters. Findings showed that L. sericata from each of the three regions could complete their development within the temperature range of 16–34 °C. There was notable congruence in the total developmental period of L. sericata from different regions within the 22–28 °C range. However, at temperatures below 20 °C and exceeding 30 °C, discernible differences in developmental duration were observed between populations, and at 34 °C, the total developmental period showed statistical differences. Comparisons of pupal length indicate obvious regional differences, with an interplay between temperature and region suggesting a dual influence on L. sericata development. The thermobiological parameters revealed differences in the adaptability of L. sericata to temperature across different regions. In summary, the experimental results provide pivotal insights for applying regional L. sericata data in the estimation of PMI_min, and it is recommended that regional specificity and experimental operational discrepancies be taken into account in future estimations.