Unscented and scented LDPE trash bags do not alter blow fly attraction to vertebrate remains

Medicolegal forensic entomology allows investigators to estimate the minimum postmortem interval (mPMI) through the predictable attraction of blow flies (Diptera: Calliphoridae) to decomposing remains. Because homicide victims are frequently concealed within plastic bags, the behavioral responses of flies to these physical barriers requires formal investigation. Furthermore, the rising prevalence of scented trash bags introduces an unstudied olfactory variable to carrion colonization. To assess these potential physical and olfactory barriers, raw chicken legs were either left unbagged (control) or completely enclosed within white plastic bags (unscented or lavender-scented low-density polyethylene (LDPE)) and put inside plastic bottle traps to monitor fly attraction over a one-week period. Here we show that Lucilia coeruleiviridis was the overwhelmingly dominant species captured, followed in decreasing abundance by Phormia regina, Sarcophaga spp., Musca spp., and Cochliomyia macellaria. Bagging treatment had no significant effect on trap captures, and the absence of a species-by-treatment interaction indicates similar behavioral responses across all observed taxa. Consequently, thin LDPE scented trash bags do not disrupt blow fly attraction to remains, providing reassurance to medicolegal investigators that these commercial products are unlikely to bias mPMI estimates.