Cuckoo Bee

Cuckoo Bee, Nomada fucata, on Gorse.  Keston Ponds, 27 March 2012.

I was sure this was a wasp when I photographed it, but it is actually a bee.  Bees of this Nomada genus are known as Cuckoo Bees. They lay an egg in the brood cell of another species of bee, in this case a solitary bee called Andrena flavipes, the Yellow-legged Mining Bee. When the egg hatches the Nomada larva kills the host larva and eats the food stored by the host bee. This sort of behaviour is not rare in insects, and a quick early death is far from the most unpleasant fate that could befall the victims.

Species that steal the food stored by their victims are called cleptoparasites.