Unknown wasp for I.D. please.

[Bee Wolf]

Hi all,

First post so here goes.

Observed this wasp last summer (August) nesting in some hollow plant stems I bundled together and hung out in my back garden.
Unfortunately I never managed to see what prey species it was feeding to its larvae.
I opened up the stem this spring to reveal 12 pupae.
So far 3 have 'hatched' (probably a lot earlier than they would in the 'wild').
Two of the adults to emerge are the same as the wasp I observed nesting.
The other to emerge is a parasitic wasp species (I can only assume) which died before I photographed it.
I know the pictures are not up to much but I'd appreciate any help with identification.

Cheers,

Stevie in Edinburgh.

[eucera]

I have a feeling this just might be a Crabronid wasp in the genus Rhopalum. You don't say where you are from. Was there any water/river/stream/pond nearby??

[Bee Wolf]

Hi Eucera,

Thanks for the response.

I live in Edinburgh and the Water of Leith runs past the bottom of my back yard.

All of the following may or may not be obvious in the photographs but the wasp was around 7mm in length. The abdomen is a dull orange/brown with a black thorax and head. There are creamy white markings on the face and legs.

We've had a couple of fantastic days weather wise up here and I have seen what I think are a couple of very similar specimens flying around some holes I bored in old fence posts (a lot earlier than last years sightings)!

Hope this helps.

Meanwhile I'll troll the web looking for pictures based on your suggestion.

Thanks again,

Stevie in Edinburgh.

[Bee Wolf]

Thanks for the lead Eucera. I found some pics on a German site (HymIS) and from these I'm pretty sure my wasp is a Rhopalum Clavipes (see links).

What's the significance to this species of being near a fresh water body?

Thanks again Eucera. I'm going to see what I can find out about the natural history of this beast.

Stevie


http://www.hymis.de/images002/3968_R...ex_488x600.jpg

http://www.hymis.de/images002/3967_R...ex_469x600.jpg