Pupal cases of four Nearctic species of Laphria (Diptera: Asilidae).

The pupal cases of the Nearctic robber flies Laphria canis Williston, 1883: L. ferox Williston, 1883: L. macquarti (Banks, 1917): and L. posticata Say, 1824 are described and illustrated. A key is provided to the pupal cases of these and seven other species of Laphria previously described. A revised key also is included for the pupal cases of three genera of Laphriinae: Andrenosoma, Lampria, and Laphria.