Stenopogon

Dennis, D. Steve, Barnes, Jeffrey K. & Knutson, Lloyd, 2008, Pupal cases of Nearctic robber flies (Diptera: Asilidae), Zootaxa 1868 (1), pp. 1-98 : 38

Key to known pupal cases of Nearctic species of Stenopogon

1 Middle and outer posterior antennal processes fused, appearing shorter than inner or first process, outer or third process elbowed; distinct labral keel absent; prothoracic spiracle on slight callosity with small anterior tubercle; segments 2–7 with 3 bristle­like spines behind each spiracle................................................... .................................................................................................................... Stenopogon rufibarbis Bromley

­ Posterior antennal processes subequal in length, outer or third process not elbowed; labral sheath with slight keel; prothoracic spiracle surrounded by thickened cuticle basally; segments 2–7 with 2 bristle­like spines behind each spiracle............................................................................. Stenopogon inquinatus Loew