Battle for the burrows

Have you noticed the pile of wood dust by one of the benches at the bottom of the ramp?

Here's what's making it... Ectemnius cephalotes - sometimes known as a Big Headed Wasp

In she goes - Phil Collins

The female wasps excavate nest burrows in old pieces of wood. They will often share an entrance – three were seen entering before any of them came out again.
They construct chambers within the wood and provision them with paralysed flies for the wasp's larvae to feed on. We have even been able to identify the flies they are catching with at least one large Bluebottle and a Cleg!

However, the wasps are not alone... a fly has been loitering outside the hole.

Eustalomyia species are cleptoparasites (from Greek klepto, to steal) and lay their eggs in the wasps' brood chambers. On hatching, the fly larvae consume the provisions that have been left by the female wasp for her own larvae to eat. The flies usually wait until the wasp has left before entering the burrow but that did not seem to be the case here with some daring raids!.

Eustalomyia hilaris - lurking  - Phil Collins

We actually saw a fly go into the nest shortly after a wasp had gone in. I have no idea what would happen if wasp and fly met in the burrow; I suppose if there are many brood chambers off the main burrow they would provide a hiding place if needed!

Jerry Hoare has compiled some superb footage of these industrious insects at work...

Click here to be amazed!

So thanks to Phil and Jerry for providing me with so much great information and to Ted Benton for confirming the identity of this difficult group of wasps...

15-6-18