Solitary wasp nests in bat boxes

[The Woodman]

Found several small solitary wasp nests inside bat boxes today.

Can anyone tell me what species of wasp makes these small nests, please?

The cell cluster is very small, perhaps 10 - 15 cells.

One of them has built onto last years nest.





Bats do not seem to mind them, one box had two soprano Pipistrelles roosting alonside the wasp nest.

[Matt Smith]

It is a nest of one of the social wasp species, what you can see is just the first series of cells. It will eventually get much bigger as the colony grows, so your Pips may have to find another summer roost later on in the season.

[The Woodman]

Hi Matt

These nests never get any bigger than what you see in the images (golf ball size) and they're made by a single wasp.

I've always thought they were solitary wasps rather than social. I'll keep my eyes on development and thanks for the comment.

There was a similar nest hanging under the apex of a house in the village last year in the open as it were and that nest grew to the size of a large grapefruit. As it decayed you could see three or four layers of cells.