Effects of Automotive Gasoline on Colonization and Development Rates of Forensically Important Arthropods

Forensic entomology is used in criminal investigations to determine time and location of death using arthropod life cycle stages and comparison of arthropods on the body to species native to the region. Development rates used to determine post-mortem interval (PMI) can be influenced by environmental and chemical factors. Cadavers can become contaminated with chemicals prior to death or post-mortem either unintentionally or intentionally to cover evidence. Research regarding the effects of chemicals on forensically-important arthropods is significant, as these effects can result in inaccurate PMI by changing colonization and development rates. This research will aim to assess whether unleaded automotive gasoline, which is commonly used as fuel to burn bodies, will influence arthropod colonization and development rates before the body is burned. Experiments will be performed through spring and summer 2015. Blow flies (Calliphoridae) are used in PMI determination as they are the most abundant arthropods during early stages of decomposition. The species of interest for laboratory experimental research are Lucilia sericata and Phormia regina. Blow flies will be reared on an artificial diet with gasoline added. Pig cadavers will be used for field experiments, and will be thoroughly immersed in gasoline for one hour. Cadavers will be placed in a wire enclosure to prevent skewed results from vertebrate foraging. If results support our hypothesis that gasoline will delay developmental rates, future studies should aim to determine how to apply gasoline contamination to PMI