Bee-fly

Large Bee-fly (or Bee Fly) - Bombylius major

Two days ago at Gaddon Loch, I was watching one of these chucking its eggs into the burrow entrances of nesting solitary bees.

There is a bank favoured by burrowing solitary bees and a beefly was methodically going round and flicking an egg into each entrance. Upon hatching, the beefly larva will crawl in further and devour the larva of the solitary bee along with the foodstore left for that larva. What eventually emerges from that burrow will be a bee-fly instead of the expected solitary bee.

This one was seen today in my garden nectaring from honesty flowers.