Forensic entomology samples. Test tubes containing samples of insect larvae found in a corpse. Identification of the flies can provide information on how long the body was dead before it was found. Different species of fly and other insect lay their eggs at different times, and their larvae feed on different tissues. By studying the insect population in a corpse, a very accurate time of death can be calculated, which is an important piece of information in helping to identify the killer.