Intra-puparial development of forensically important Sarcophaga princeps at different constant temperatures.

Sarcophaga princeps Wiedemann, 1830 (Diptera: Sarcophagidae) is a species widely distributed in the Oriental and parts of the Palearctic regions. Documented cases have reported its colonization of human corpses and association with livestock myiasis, highlighting its significant value in forensic and medical research. However, current methods for estimating the intra-puparial age of S. princeps, which accounts for more than half of the entire immature stage, remain lacking. In this study, pupae were sampled at four constant temperatures (16, 22, 28, and 34 °C), and intra-puparial morphological changes were observed and photographed under a stereomicroscope after removal of the puparium. Results showed that the intra-puparial developmental period of S. princeps could be divided into 12 sub-stages based on overall morphological changes. Structures such as compound eyes, mouthparts, antennae, thorax, legs, wings, and abdomen were also used for age estimation; these were individually observed, photographed with local magnification, and their developmental processes were categorized into 6-10 stages. The temporal ranges of each sub-stage and structural appearance were meticulously recorded. This study provides essential baseline data for estimating minimum postmortem interval (PMImin) using intra-puparial morphological characteristics of S. princeps.