thick-headed fly
thick-headed fly, (family Conopidae), any member of a family of elongated, wasplike flies (order Diptera) that have a head thicker than the thorax. They are brownish in colour and often have yellow markings. Most are between 6 and 25 mm (0.2 and 1 inch) long.
All species have a long, slender proboscis (feeding organ) that in some species is elbow-shaped. Eggs are deposited on or in host insects such as adult wasps, bumblebees, or grasshoppers, on which the larvae feed.
This article was most recently revised and updated by Amy Tikkanen.
Citation Information
Article Title:
thick-headed fly
Website Name:
Encyclopaedia Britannica
Publisher:
Encyclopaedia Britannica, Inc.
Date Published:
28 March 2011
Access Date:
November 14, 2026