Conopid fly Physocephala australiana

I thought these flies were rather cute until I read a bit about them:

Most conopids are found around flowers where they mate and lay their eggs directly onto the abdomens of Social insects such as ants, bees and wasps.

"The larvae develop first by feeding on haemolymph and in their last instar attack the tissue of the thorax, weakening and then killing the host. Pupation takes place in the abdomen. "