Ruby-tailed Wasps (Chrysis angustula)

Every summer up to a dozen of these little jewel-like cuckoo wasps visit this Knapweed, which grows in our garden. They seem to be attracted to something on the flower buds. Other insects come too. The buds are not sticky. We have quite a lot of the native Greater Knapweed along the coast and I have never seen insects swarming all over the buds like this.

Peter Byles, Ceibwr.