Identifying digger

Cerceris rybyensis – Male

I took this photo of this tiny little wasp in my garden back in early July but afterwards really struggled to identify it. My well-thumbed Guide to the Insects of Britain and Europe failed me. I didn’t even get to a genus, although I was pretty sure it was some kind of Digger Wasp. I had a look on the BWARS site, the website of the Bees, Wasps and Ants Recording Society http://www.bwars.com but blanked again.

So I sent out a tweet and a picture via the Twittersphere and literally within minutes Ian Beavis @TWBC_Museum got back to me with an identification. He tweeted ‘Cerceris rybyensis – the segment-wide yellow band halfway down abdomen is v distinctive’. Well once I had the name I googled it to look at a range of other pictures and he was absolutely spot-on. Although in my photo the wings obscure this identification feature a little. A few minutes later he kindly tweeted the further tip that ‘as a genus Cerceris stand out for their rounded ‘Michelin-man style’ segments. What a gentlemen.

So this little fellow is a Digger Wasp Cerceris rybyensis, as I suspected, possibly a male. Digger Wasps are solitary wasps commonly associated with sandy soils and chalk grassland. They generally prey on small and medium-sized bees returning to their nests with pollen which they paralyse by stinging. They are largely confined to southern Britain.