The Conopidae, sometimes known as Thick-headed Flies, is a family of flies within the Brachycera suborder of Diptera.  Conopids are often found at flowers feeding on nectar and all Conopids are obligate parasitoids of bees and wasps.  The four Highland species are at the northern limit of their distribution, and no other conopids occur in Scotland apart from two old records of Myopa testacea which are well to the south of Highland.

Species are very different from each other, but the family is recognised by having a head slightly broader than the thorax, and relatively long antennae projecting forward. Other families of flies (some hover- and soldierflies) have forward-pointing antennae, but should not be confused with our Conopids, which should be easily identified by reference to the pictures.

Myopa buccata is also a vernal (spring) species which separates it temporally from the others.