Wednesday, July 25, 2012


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!

This was my favourite find of the day: a wonderful Golden-ringed dragonfly. This is the first time that I've seen this species outside of the Highlands of Scotland. Later on a second individual flew down the path in front of me!

These spiders were very common in the short rough grassland right by the cliff edge. They are Bordered Orb-weavers (Neoscona adianta).

And this is a very interesting little beastie. It's the calliphorid fly, Cynomya mortuorum. With a name like mortuorum I suspected that an internet search would turn up some interesting information. This is what the species account on Wikipedia says:

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:



  1. Nice pics Steve,and the Golden-ringed must be one of our most spectacular dragonflies.

  2. Thanks, Peter....I was really hoping to see Golden-ringed this year, so two within a few hours was a real treat for me!