Look at this gorgeous North American solitary wasp (click the image for a bigger version if you like). Now wonder about its name – why is it named after a bird? After all, cuckoos are hardly known for their brightly coloured plumage. The answer lies in its lifestyle. Cuckoo wasps are so named because they breed by surreptitiously laying an egg in the nest of another (usually) wasp or bee – just as cuckoos do to other birds. Then the young cuckoo wasp larva hatches out, eats the larva of the host animal, and then enjoys the provisions the mother has left behind for her own offspring. From the cell emerges not the expected bee or wasp, but another species entirely – the adult cuckoo wasp.
The cuckoo wasps (and there are many species, including quite a few in the UK) have some special adaptations to help them do this. They have a really long egg-laying ovipositor, that can extend telescopically to let them insert an egg deep into a host cell. They also have the ability to curl up into a protective ball, like some woodlice do; with strong armour on the back, and gaps underneath where they can tuck their legs and antennae safely. It must be a hazardous life being a parasite – those host bees and wasps can bite and sting!