MIDGE LARVAE (DIPTERA, CHIRONOMIDAE) AS INDICATORS OF POSTMORTEM SUBMERSION INTERVAL OF CARCASSES IN A WOODLAND STREAM - A PRELIMINARY-REPORT

Data on colonization of rat carcasses by aquatic insects in riffle and pool areas of a small woodland stream were obtained to elucidate patt erns potentially useful for determining the postmortem submersion inte rval of corpses in flowing water habitats. After 39 days, the carcasse s had no visual signs of deterioration in the absence of large scaveng ing animals. Midge larvae (Diptera: Chironomidae) were the dominant in sects colonizing the carcasses. No patterns in numbers of larvae over time were evident, but the diversity of genera increased after 29 days in the riffle. Also, Orthocladius larvae did not begin to colonize th e carcasses until after 13 days of submersion in the riffle and after 20 days of submersion in the pool. Although separated only by 20 m, th e riffle and pool rats had dissimilar faunal assemblages. This suggest s that different indices for determining the postmortem submersion int erval of corpses based on midge larvae colonization should be develope d for these two habitats. This investigation does not provide replicat ed data, but does shed light on what may happen to mammalian carcasses placed in a stream at a particular time of the year.