Caterpillars and Parasites

The above Caterpillar was found in my back garden on Knapweed on May 15th this year. I have identified it as the larva of the Double Square-spot Xestia triangulum Moth. It did not seem to be moving very much or interested in eating, and on closer inspection, the reason becomes clear. Looking at the top right hand end of the larva you can just make out some tiny white blobs. I have tried to enlarge this in the photograph below.

Here you can see some tiny white eggs laid by a parasite of some kind. I decided to keep the Caterpillar in my rearing tent to see what would happen. On May 31st, the eggs hatched out and I was rewarded with many tiny Parasitic Wasps - see photograph below.

I have no idea what species of Wasp this is, but will do my best to find out. I will then update this blog.