Proctacanthus

Dennis, D. Steve, Barnes, Jeffrey K. & Knutson, Lloyd, 2008, Pupal cases of Nearctic robber flies (Diptera: Asilidae), Zootaxa 1868 (1), pp. 1-98 : 75-76

Key to known pupal cases of Nearctic species of Proctacanthus

1 Labral sheath with or without slight posterior keel; prothoracic spiracle on mostly smooth callosity; posterior mesothoracic callosity with 1–3 anterior swellings; abdominal spiracles semi­circular; abdominal segment 8 with 0–2 dorsal spurs; segment 9 lacking ventral posterolateral processes or with only minute processes......................................................................................................................................................2

­ Labral sheath with distinct posterior keel; prothoracic spiracle on rugose callosity; posterior mesothoracic callosity without anterior swellings; abdominal spiracles mostly elongate­oval (semi­circular in P. philadelphicus ); abdominal segment 8 with 8–12 dorsal spurs; segment 9 with small but well­developed ventral posterolateral processes.........................................................................................................................3

2 Posterior antennal processes longer than anterior antennal processes; labral sheath with inverted V­shaped rugoseness; maxillary sheath without apical process; wing sheath with 4 small, median, tubercle­like swellings; abdominal segment 1 with dorsal transverse row of 20 spurs ..... Proctacanthus hinei Bromley ­ Posterior antennal processes not longer than anterior antennal processes; labral sheath rugulose, but not inverted V­shaped; maxillary sheath with small, apically rounded process posteriorly; wing sheath with 1– 2 small median tubercles; abdominal segment 1 with dorsal transverse row of 14–18 spurs ....................... ...................................................................................................................... Proctacanthus rufus Williston

3 Proboscial sheath with slight tubercle­like swelling on each side of midline anterior to median posterior tubercle; maxillary sheath with apically rounded posterior process ..... Proctacanthus milbertii (Macquart)

­ Proboscial sheath without tubercle­like swelling on each side of midline anterior to median posterior tubercle; maxillary sheath without apically rounded posterior process.......................................................4

4 Wing sheath with 2–3 basal tubercles, without tubercle­like projections in front of abdominal segment 1 and between basal tubercle and dorsum; abdominal segment 1 with dorsal transverse row of 17–21 spurs; segment 8 with 4–6 ventral bristle­like spines on each side and pair of median tubercles posterior to the spines ........................................................................................................... Proctacanthus micans Schiner

­ Wing sheath with 1 basal tubercle and 1–3 tubercle­like projections in front of abdominal segment 1 and between basal tubercle and dorsum; abdominal segment 1 with dorsal transverse row of 25 spurs; segment 8 with 7–11 ventral bristle­like spines on each side and without median tubercles posterior to the spines.... ....................................................................................................... Proctacanthus philadelphicus Macquart