Our front porch has been host to some shiny black Virginia carpenter bees. Earlier this year a couple females chewed burrows in the woodwork in which to store pollen and lay eggs. I had been keeping my eye on the nests to see if I might be able to catch an emerging young bee.

This afternoon, however, I found something even more interesting. Behold!

A carpenter bee nest entrance (lower left) shows signs of activity, but what emerged from pupation were not bees but parasitic Xenox tigrinus flies that had, as maggots, consumed the developing larvae.

Xenox tigrinus bee fly must have been successful in breaching a carpenter bee’s defenses. Death by parasite is the unfortunate fate of many insects, and bee flies inflict their share of damage on solitary bees whose nests are inadequately protected. Below are a few more photos of the Xenox flies.

The patterned wings of Xenox tigrinus are unmistakable.

The flies let me approach closely while their cuticles hardened.

Hanging out.