Seasonal colonization and decomposition of rat carrion in water and on land in an open field in South Carolina.

Decomposition and insect colonization of rat, Rattus rattus L., carrion on land and in water were compared during summer and winter in a plowed field in northwestern South Carolina. During winter, carcasses on land reached the dried-remains stage of decomposition, whereas carcasses in water reached the early-floating stage. During summer, carcasses in both habitats entered the final-remains stage of decomposition in 1-2 wk. Fewer than 30 species of carrion insects were recorded from the carcasses over the duration of the study, probably reflecting the small size of the carcasses and the depauperate fauna of the habitat. Three species of blow flies--Cynomyopsis cadaverina (Robineau-Desvoidy), Calliphora vicina Robineau-Desvoidy, and Lucilia illustris (Meigen)--colonized carrion on land during winter, but no insects colonized carrion in water during winter. Two species of blow flies, Cochliomyia macellaria (F.) and Phaenicia sericata (Meigen), and 1 species of flesh fly, Sarcophaga bullata Parker, colonized the carrion on land and in water during summer; the blow fly, Phormia regina (Meigen), colonized only the carrion on land. This study demonstrated seasonal variation in decomposition and colonization patterns of carrion in contrasting habitats, with important implications for forensic entomology.