Temperature-dependent development and multimodal intra-puparial age estimation of Sarcophaga formosensis (Diptera: Sarcophagidae).

Sarcophaga formosensis (Kirner & Lopes, 1961) (Diptera: Sarcophagidae) is a forensically significant necrophagous fly. However, its utility in estimating the minimum postmortem interval (PMImin) is limited by a lack of baseline bionomic data and the inherent challenges of intra-puparial age estimation. In this study, we established comprehensive developmental datasets for S. formosensis across five constant temperatures (15-35 °C). The lower developmental threshold (D0) was 10.27 ± 0.19 °C, with a thermal summation constant (K) of 5396.11 ± 129.00 degree-hours. Additionally, 35 °C was identified as the upper lethal threshold. To aid intra-puparial age determination, a chronological morphological atlas was systematically constructed. Furthermore, to overcome the discrete nature of morphological milestones, hyperspectral imaging (HSI) was integrated with machine learning (ML) for non-destructive age estimation. The XGBoost model effectively extracted temperature-independent spectral features, achieving superior predictive accuracy (R2 = 0.92, MAE = 8.35 degree-days). This study provides the first systematic developmental parameters and morphological markers for S. formosensis, while validating an HSI-ML framework for quantitative, non-destructive intra-puparial age estimation in forensic casework. These findings provide critical data references and innovative methodologies to facilitate the application of this species in forensic entomology.