Pupal cases of Nearctic robber flies (Diptera: Asilidae) Author Dennis, D. Steve Author Barnes, Jeffrey K. Author Knutson, Lloyd text Zootaxa 2008 2008-09-03 1868 1 1 98 https://biotaxa.org/Zootaxa/article/view/zootaxa.1868.1.1 journal article 10.11646/zootaxa.1868.1.1 1175­5334 5133591 Key to known pupal cases of Nearctic species of Efferia 1 Labral sheath with low apical keel on posterior third or more; proboscial sheath with posterior tubercle.2 ­ Labral sheath with raised, tubercle­like keel on posterior half; proboscial sheath with spine­like posterior process ............................................................................................................. Efferia benedicti (Bromley) 2 Proboscial sheath with single median tubercle on each side of midline; abdominal segment 8 with 2–3 dorsal posterolateral spurs on each side of midline and 5–8 bristle­like spines below and behind each spiracle...............................................................................................................................................................3 ­ Proboscial sheath with 3–8 minute tubercles on each side of midline; abdominal segment 8 with 0­1 dorsal spurs on each side of midline and 2–3 bristle­like spines below and behind each spiracle...................4 3 Wing sheath rarely with median tubercle, abdominal segment 1 with 3 bristle­like spines behind each spiracle; abdominal segments 2–4 often with bifurcate dorsal spines; segment 8 with 2 dorsolateral spurs on each side and 6–14 subequal ventral bristle­like spines .................................. Efferia aestuans (Linnaeus) ­ Wing sheath with median tubercle; abdominal segment 1 with 6 bristle­like spines behind each spiracle; abdominal segments 2–4 without bifurcate dorsal spines; segment 8 with 3 dorsal spurs on each side and 16 long and short ventral bristle­like spines .................................................. Efferia triton (Osten Sacken) 4 Anterior mesothoracic spines apically rounded; wing sheath without median tubercle; abdominal segment 1 with 14 dorsal spurs; segment 8 with 14 ventral bristle­like spines .................... Efferia frewingi Wilcox ­ Anterior mesothoracic spines distinctly acuminate; wing sheath with median tubercle; abdominal segment 1 with 12 dorsal spurs; segment 8 with 2 ventral bristle­like spines ................. Efferia helenae (Bromley)