title: Post-Colonization Interval Estimates Using Multi-Species Calliphoridae Larval Masses and Spatially Distinct Temperature Data Sets: A Case Study.
abstract: Common forensic entomology practice has been to collect the largest Diptera larvae from a scene and use published developmental data, with temperature data from the nearest weather station, to estimate larval development time and post-colonization intervals (PCIs). To evaluate the accuracy of PCI estimates among Calliphoridae species and spatially distinct temperature sources, larval communities and ambient air temperature were collected at replicate swine carcasses (N = 6) throughout decomposition. Expected accumulated degree hours (ADH) associated withCochliomyia macellariaandPhormia reginathird instars (presence and length) were calculated using published developmental data sets. Actual ADH ranges were calculated using temperatures recorded from multiple sources at varying distances (0.90 m-7.61 km) from the study carcasses: individual temperature loggers at each carcass, a local weather station, and a regional weather station. Third instars greatly varied in length and abundance. The expected ADH range for each species successfully encompassed the average actual ADH for each temperature source, but overall under-represented the range. For both calliphorid species, weather station data were associated with more accurate PCI estimates than temperature loggers associated with each carcass. These results provide an important step towards improving entomological evidence collection and analysis techniques, and developing forensic error rates.
authors.affiliation: Department of Entomology, Michigan State University, 243 Natural Science Building, East Lansing, MI 48824, USA. weath108@msu.edu.
authors.forename: Courtney R
authors.initials: CR
authors.lastname: Weatherbee
authors.affiliation: Department of Entomology, Michigan State University, 243 Natural Science Building, East Lansing, MI 48824, USA. pechalje@msu.edu.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Pechal
authors.affiliation: Department of Entomology, Purdue University, 901 West State Street, West Lafayette, IN 47907, USA. tstampe@purdue.edu.
authors.forename: Trevor
authors.initials: T
authors.lastname: Stamper
authors.affiliation: Department of Entomology, Michigan State University, 243 Natural Science Building, East Lansing, MI 48824, USA. benbow@msu.edu.|Department of Osteopathic Medical Specialties, Michigan State University, 243 Natural Science Building, East Lansing, MI 48824, USA. benbow@msu.edu.|Ecology, Evolutionary Biology and Behavior, Michigan State University, 243 Natural Science Building, East Lansing, MI 48824, USA. benbow@msu.edu.
authors.forename: M Eric
authors.initials: ME
authors.lastname: Benbow
keywords: Cochliomyia macellaria; Phormia regina; decomposition; forensic entomology; necrobiome; post-mortem interval; variability