Proctacanthus philadelphicus Macquart

Dennis, D. Steve, Barnes, Jeffrey K. & Knutson, Lloyd, 2008, Pupal cases of Nearctic robber flies (Diptera: Asilidae), Zootaxa 1868 (1), pp. 1-98: 79-80

publication ID 10.11646/zootaxa.1868.1.1

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Proctacanthus philadelphicus Macquart


Proctacanthus philadelphicus Macquart  

The pupal case of P. philadelphicus   was briefly described by Packard (1870), Malloch (1917), and Bromley (1946). The following description is based on a male pupal case with associated pinned adult in the United States National Museum labeled "Crown Point, Ind.; IV­24­34; reared from Lachnosterna   ?; Luginbill & Painter Col1s., 106" and two males with associated pinned adults from the Illinois Natural History Survey, both labeled simply "46349."

Redescription: Greatest length, including anterior antennal processes, 23.1–30.3 mm; greatest width of thorax 8.0– 8.7 mm, greatest width of abdomen 6.5–6.8 mm, tapering to 2.7–3.1 mm at greatest width of abdominal segment 8. Integument subshining golden brown; wing sheath darker apically; spines and other processes glistening reddish brown, darker apically except for basally darker spurs; dorsal abdominal spines uniformly reddish brown.

Head with pair of dorsally flattened, ventrally wedge­shaped anterior antennal processes not joined at base and group of 3 basally fused, apically acute posterior antennal processes located ventrolaterally on each side; middle and outer posterior processes closer together and fused for greater distance, appearing shorter than inner posterior process; outer posterior process wider for entire length than tapered inner and middle posterior processes; middle posterior process narrower than inner process. Labral sheath rugose, with rugose, tuberclelike keel posteriorly. Proboscial sheath rugose, especially on each side of midline, slightly bulbous and with ridge on each side of midline posteriorly; with small, median tubercle just posterior to ridges. Maxillary sheath rugose, with small, posterior tubercle on each side of proboscial sheath.

Anterior coxal sheath irregularly rugulose with anterior, median, longitudinal split. Prothoracic spiracle elongate­oval, facing posteriorly, situated on rugose callosity midlaterally at anterior margin of thorax. Anterior mesothoracic spines consisting of pair of wide spines above base of sheath of mid legs; posterior spine straight; anterior spine slightly curved posteriorly. Posterior mesothoracic callosity medium sized, rugose, with sclerotized ridges toward dorsum and small, apically rounded to acute posterior mesothoracic spine at base of each wing sheath. Wing sheath irregularly rugose, with small basal tubercle and pair of small, unequal median tubercles; with 1–3 tubercle­like projections in front of abdominal segment 1 and between basal tubercle and dorsum. Thoracic area above wing sheath irregularly rugulose. Apex of hind leg sheath reaching to about middle of abdominal segment 4.

Abdominal spiracles elongate­oval to semi­circular, raised slightly above surface, situated along midline laterally.

Abdominal segment 1 with dorsal transverse row of 25 apically recurved spurs, some very short; outer spurs slightly shorter than others; dorsolateral bristle­like spines absent; with 8–9 lateral bristle­like spines behind each spiracle; venter obscured by wing and leg sheaths.

Segments 2–4 with 3–4 short outer spines on each side and dorsal transverse row of 6 long, apically acute spurs alternating with 8 shorter, broad or acute spines; 9–10 dorsolateral bristle­like spines on each side; and 13–14 lateral bristle­like spines behind each spiracle.

Segment 5 similar to 2–4, but with 1–3 short outer spines, 11–12 dorsolateral bristle­like spines on each side, and 15–16 lateral bristle­like spines behind each spiracle.

Segments 6–7 with 1–2 short outer spines on each side and dorsal transverse row of 6 long spurs alternating with 5 shorter spines; segment 6 with 8 dorsolateral bristle­like spines on each side and 14 lateral bristlelike spines behind each spiracle; segment 7 with 3–4 dorsolateral bristle­like spines on each side and 12 lateral bristle­like spines behind each spiracle.

Segment 2 with 12–16 mostly long ventral bristle­like spines on each side of and extending under hind leg sheaths; segments 3–7 with complete transverse row of 32–45 mostly long ventral bristle­like spines, some spines crossing over each other; more posterior segments with fewer bristle­like spines.

Segment 8 with 4–5 dorsal spines on each side of dorsal midline, small spiracle at lateral midline, 5–6 lateral bristle­like spines on each side, and 7–11 bristle­like spines on each side of ventral midline.

Segment 9 with pair of long dorsal posterolateral processes curved toward each other; pair of short, straight ventral posterolateral processes not fused basally to dorsal posterolateral processes; pair of widely separated terminal ventromedian tubercles; pair of approximate ventromedian tubercles anterior to terminal tubercles; and pair of anterior ventromedian callosities touching basally and terminating in sclerotized, rug­ ose, tubercle­like area. Area bounded by dorsal and ventral posterolateral processes with pair of outer, dorsally tubercle­like ridges and 2–3 inner ridges on either side of midline.