Ommatius tibialis Say

Dennis, D. Steve, Barnes, Jeffrey K. & Knutson, Lloyd, 2008, Pupal cases of Nearctic robber flies (Diptera: Asilidae), Zootaxa 1868 (1), pp. 1-98 : 50-51

Ommatius tibialis Say

( Figs 29–31 )

The following description is based on a female pupal case associated with a pinned adult of Ommatius tibialis from the United States National Museum. It is labeled "Haddon Hts., N.J.; 7/5/33; L.J. Bottimer."

Description: Greatest length, including anterior antennal process, 12.8 mm; greatest width of thorax 3.2 mm; greatest width of abdomen 3.2 mm; tapering to 1.3 mm at greatest width of abdominal segment 8. Integument subshining yellowish to golden brown; spines and other processes glistening reddish brown, darker apically, except for uniformly reddish­brown abdominal spurs and spines.

Head with pair of long, dorsoventrally flattened anterior antennal processes fused basally and group of 3 basally fused posterior antennal processes located ventrolaterally; middle and outer posterior processes closer together and fused for greater distance, appearing shorter than inner or first posterior process; outer or third posterior process apically acute, inner and middle posterior processes more rounded, the former with an outer flattened area with small lip. Labral sheath mostly composed of large, apically rounded, rugose process. Proboscial sheath smooth except for rugose swellings on each side of midline posteriorly, medially concave tubercle separated from swellings by narrow ridge of cuticle. Maxillary sheath mostly smooth with small median tubercle on callosity posteriorly.

Anterior coxal sheath smooth, with anterior, median, longitudinal split. Prothoracic spiracle elongate­oval, facing posteriorly on small, smooth callosity, situated midlaterally at anterior margin of thorax. Anterior mesothoracic spines absent. Posterior mesothoracic callosity smooth, with slightly sclerotized margin dorsally; posterior mesothoracic spine absent. Wing sheath smooth except for some shallow basal pits and rugulose posterior third. Thoracic area above wing sheath smooth. Apex of hind leg sheath reaching between middle and posterior margin of abdominal segment 3.

Abdominal spiracles upraised, reddish brown, more round than prothoracic spiracle, situated along midline laterally.

Abdominal segment 1 with dorsal transverse row of 13 long apically recurved spurs on anterior margin of segment, 1 dorsolateral bristle­like spine on each side, and 5 lateral bristle­like spines behind each spiracle; venter obscured by wing and leg sheaths.

Segments 2–7 with dorsal transverse row of 6 long, straight to slightly apically recurved spurs and 7 short, straight spines, 3–7 (usually 4–5) dorsolateral bristle­like spines of unequal size, and 6–7 lateral bristle­like spines of unequal size behind each spiracle.

Segment 2 with 6–7 ventral bristle­like spines on each side of hind leg sheaths. Segments 3–7 with complete transverse row of 19–26 bristle­like spines of unequal size; median 2–4 bristle­like spines usually short; long bristle­like spines apically curved.

Segment 8 with 2 long dorsal spurs and very short spine between them, small spiracle, and long dorsolateral bristle on each side of midline; with 6–7 lateral bristle­like spines on each side and 2 short ventral bristlelike spines on each side of midline.

Segment 9 with pair of long, dorsally curved dorsal posterolateral processes; pair of slightly shorter, ventrally curved ventral posterolateral processes; and pair of ventral posteromedian acuminate processes onethird as long as ventral posterolateral processes.

Figures

FIGURES 29–31. Ommatius tibialis Say, 29. ventral view, 30. lateral view, 31. dorsal view.