Unexpected insects leave clues for entomologists
22 Apr 2015 by Evoluted New Media
Entomologists have discovered insects – normally not associated with human corpses – can provide clues from dead bodies.
A research team at Sam Houston State University studied four unseen insect–cadaver interactions and found the first insects that prey on fresh corpse in the autumn.
“Baseline knowledge of insect-cadaver interactions is the foundation of forensic entomology, and unique observations have the potential to expand our understanding of decomposition ecology,” the researchers said in their paper.
The scientists observed several species from the scorpionfly family known as Panorpa nuptialis to be the first insects to feed upon a freshly placed corpse in the autumn.
Dr Jason Byrd, President of the North American Forensic Entomology Association said: “It's significant that Panorpidae were the first insects to feed upon a freshly-placed corpse. Entomologists rely on insect succession to help them determine portions of the post-mortem interval, and having a study that indicates that Panorpidae are early-arriving species will certainly assist forensic entomologists in their investigations”.
In the study, published in Journal of Medical Entomology, the researchers also investigated the colonisation and mating of insects linked to aquatic conditions. Hoverflies, from the Syrphidae maggots family, showed that they can colonise a corpse in an aquatic environment. They also found that adult flies from Psychodidae family mated and laid eggs on an algal film that had been recently removed from water.
Also, the scientists found that noctuid caterpillars chew and ingest dried human skin, a clue that could be used to explain various after death events that influence human remains.
“Roaches, ants, crayfish, starfish, bees, and wasps all leave characteristic markings as a result of their scavenging behaviour. Knowledge that a noctuid is an opportunistic scavenger will be beneficial to entomologists because the pattern of scavenging is likely different than that of other insects, and it should not be accidentally attributed to a pattern injury from a human perpetrator,” said Dr Byrd.
Paper: http://jme.oxfordjournals.org/content/early/2015/01/21/jme.tju023
