Numbers
Nearctica lists 67 species for North America.
800 species are described worldwide
Identification
Medium-sized, brownish flies, many of which resemble small thread-waisted wasps. The abdomen is usually elongate and slender basally, the head is slightly broader than the thorax and the antennae are long. All species have a very long and slender proboscis; in some species the proboscis is elbowed. the wing venation is similar to that in the Syrphidae, but there is no spurious vein. Conopids may be distinguished from syrphids that lack a spurious vein by their long, slender proboscis.
Habitat
The adults are usually found on flowers.
Food
Larvae are endoparasites, chiefly of adult bumblebees and wasps. Adults take nectar.
Life Cycle
Flies oviposit on hosts during flight. Larvae feed on bumblebee, wasps, etc.
