Post-Colonization Interval Estimates Using Multi-Species Calliphoridae Larval Masses and Spatially Distinct...

Area of Science:

• Forensic entomology
• Ecological entomology
• Post-colonization interval estimation

Background:

• Current forensic entomology relies on largest Diptera larvae and nearest weather station data for post-colonization interval (PCI) estimation.
• Accuracy of PCI estimates can be influenced by species and temperature data source variability.

Purpose of the Study:

• To evaluate the accuracy of PCI estimates using different Calliphoridae species and spatially distinct temperature sources.
• To assess the impact of temperature data collection methods on forensic entomology findings.

Main Methods:

• Larval communities and ambient air temperature were collected from six replicate swine carcasses during decomposition.
• Expected accumulated degree hours (ADH) were calculated using published developmental data for Cochliomyia macellaria and Phormia regina third instars.
• Actual ADH ranges were determined using temperatures from on-site loggers, a local weather station, and a regional weather station.

Main Results:

• Third instar larvae varied significantly in length and abundance.
• While expected ADH ranges encompassed average actual ADH, they generally under-represented the actual range.
• Weather station temperature data yielded more accurate PCI estimates for both calliphorid species compared to on-site carcass loggers.

Conclusions:

• Weather station data improve the accuracy of post-colonization interval estimation in forensic entomology.
• Findings contribute to refining entomological evidence analysis and developing forensic error rates.
• This study highlights the importance of considering temperature data source and spatial relevance in forensic investigations.