# Temperature-dependent developmental modeling of protophormia terraenovae (Diptera: Calliphoridae) and its application in PMI inference

## TL;DR

This study models the development of a blow fly species in cold regions to improve postmortem time estimation in forensic investigations.

## Contribution

New temperature-dependent developmental models for Protophormia terraenovae to enhance PMI estimation accuracy.

## Key findings

- Developmental duration decreased from 779.33 hours at 15°C to 396.67 hours at 25°C.
- Hatching and third-instar stages showed the strongest temperature sensitivity.
- Pupal weight was identified as a more reliable growth indicator than length or width.

## Abstract

Protophormia terraenovae is a forensically important blow fly species in cold regions. This study investigated its development at constant temperatures (15-25°C). Results showed that developmental duration significantly decreased with increasing temperature, with the total period ranging from 779.33 hours at 15 °C to 396.67 hours at 25 °C. The hatching and third-instar larval stages were most temperature-sensitive. We established Isomorphen and Isomegalen models, which visually illustrated the prolongation of development progress and the increased time required for larval growth per millimeter as temperature decreased. Thermal summation models indicated a strong linear relationship for the hatching and third-instar stages. Furthermore, we found that pupal weight was a more reliable growth indicators than length or width. This study provides fundamental developmental data and models for improving the accuracy of postmortem interval estimation using P. terraenovae in forensic practice.