Proctacanthus hinei Bromley, 1928

Dennis, D. Steve, Barnes, Jeffrey K. & Knutson, Lloyd, 2008, Pupal cases of Nearctic robber flies (Diptera: Asilidae), Zootaxa 1868 (1), pp. 1-98 : 77

Proctacanthus hinei Bromley

( Figs 46–48 )

The following description is based on a male pupal case with associated pinned adult from the Charles A. Triplehorn Insect Collection, Ohio State University. It is labeled "Sandusky, O., Cedar Point; July 13–03."

Description: Greatest length, including anterior antennal processes, 28.0mm; greatest width of thorax 6.0 mm; greatest width of abdomen, 4.5 mm, tapering to 2.0 mm at greatest width of abdominal segment 8. Integument subshining, golden brown; wing sheath slightly darker apically; spines and other processes glistening reddish brown, darker apically except for uniformly colored dorsal abdominal spines; bristle­like spines yellowish to yellowish red.

Head with pair of short, dorsally flattened, ventrally wedge­shaped, anterior antennal processes not joined at base and group of 3 basally fused, apically pointed, posterior antennal processes that are longer than anterior processes, located ventrolaterally on each side; middle and outer posterior processes subequal, longer than inner posterior process, curved posteriorly, fused for greater distance and slightly closer together than inner posterior process; inner posterior process apically curved posteriorly; outer posterior process with small, oval, flattened area on outer side basally toward dorsum. Labral sheath with inverted V­shaped rugoseness, slight apical keel, and median ridge along entire length. Proboscial sheath swollen and bulbous posteriorly, with large, swollen, rugose areas on each side of median shallow groove; with small tubercle at apex and smaller tubercles at base of sheath. Maxillary sheath rugose on inner margin, lacking apical processes, slightly swollen and very rugose just anterior to apex.

Anterior coxal sheath smooth to irregularly rugulose, with shallow pit on each side of midline just posterior to proboscial sheath; with anterior, median, longitudinal split. Prothoracic spiracle elongate­oval, on small, rounded, rugulose callosity, situated midlaterally at anterior margin of thorax. Anterior mesothoracic spines consisting of pair of long, narrow, posteriorly curved, apically pointed spines above base of sheath of mid legs; posterior spine slightly longer and wider than anterior spine. Posterior mesothoracic callosity large, rugose, with apically rounded to acute posterior mesothoracic spine; spine dark reddish brown at margin; callosity with anteromedian swelling and 2 lateral swellings toward dorsum. Wing sheath irregularly rugulose, with basal swelling directly below posterior mesothoracic callosity and 4 median, small tubercle­like swellings. Thoracic area above wing sheath irregularly rugulose. Apex of hind leg sheath reaching between posterior margin of abdominal segment 2 and middle of abdominal segment 3.

Abdominal spiracles semi­circular, light reddish brown, elevated along midline laterally.

Abdominal segment 1 with dorsal transverse row of 20 long, recurved spurs and 2 short median spurs; dorsolateral bristle­like spines absent; with 4 lateral bristle­like spines behind each spiracle; venter obscured by wing and leg sheaths.

Segments 2–5 with 1–2 (usually 1) short, outer, dorsal spines and transverse row of 7 long, recurved spurs alternating with 5–6 short, straight spines; with pair of short, median spines; other short spines often bifurcate or trifurcate; short spines placed slightly anterior to long spurs, becoming longer posteriorly.

Segments 6–7 similar to 2–5, but short spines not furcate, and both spurs and spines more bristle­like. Segments 2–5 and 6–7 with 6–7 and 10–12 dorsolateral bristle­like spines, respectively; spines usually long, straight to slightly recurved; segments 2–7 with 8–13 long, mostly straight, lateral bristle­like spines behind each spiracle.

Segment 2 with 14–16 ventral bristle­like spines on each side of and extending under hind leg sheaths; segments 3–6 and 7 with 40–43 and 28 long, ventral bristle­like spines, respectively.

Segment 8 lacking dorsal spurs, with small spiracle at midline laterally, with 8–10 lateral bristle­like spines on each side and 13–16 ventral bristle­like spines on each side of midline curved toward midline.

Segment 9 with pair of short, narrow, straight, dorsal posterolateral processes on fairly large callosities, shallow lateromedian pit, and small lateral callosity; ventral posterolateral process absent; pair of rugose ven­ tral posterolateral callosities; pair of large, widely separated, reddish­brown, ventral tubercles with small lateral callosity on each side; pair of ventromedian rugose callosities anterior to tubercles; remainder of segment irregularly rugose.

Figures

FIGURES 46–48. Proctacanthus hinei Bromley, 47. ventral view, 48. lateral view, 49. dorsal view.