I spent a bit of time at the annual Isle of Wight Bio-Blitz today. It took place at the main Compton Bay car park, just off the Military Road, a beautiful location with the advantage of an ice-cream van close by!
The use of C. mortuorum in the judicial system is most commonly applied to the medicocriminal branch of forensic entomology. It is often useful in estimating the post mortem interval of a human cadaver. By studying the morphology and stage of development of the C. mortuorum
obtained from a body, one can determine an estimate of a time of death
for that body. Plenty of variables play into the use of insects in a
criminal investigation, including temperature, certain chemicals, or
location, but determining an arthropod's stage of development on a corpse proves to be an accurate technique in estimating a time of death.
Calliphoridae eggs, like C. mortuorum eggs, usually hatch
twenty-four to forty-eight hours after being laid. These specimens, once
hatched, undergo three instars in their larval stage, which can take
anywhere from four to twenty-one days. Another three to fourteen days
account for the blow fly’s pre-pupae stage, and, finally, the pupae
stage can take an additional three to twenty days. Depending on certain
variables, a forensic entomologist can pinpoint which stage of
development a C. mortuorum is in, and how long it and the carcass it is feeding on have been there.
So now you know! Here's a video clip of this afternoon's individual: