Laphria thoracica Fabricius, 1805

Dennis, D. Steve, Barnes, Jeffrey K. & Knutson, Lloyd, 2008, Pupal cases of Nearctic robber flies (Diptera: Asilidae), Zootaxa 1868 (1), pp. 1-98 : 30-32

Laphria thoracica Fabricius

( Figs 6–7 )

The description of the Laphria thoracica pupal case is based on the following specimens from the United States National Museum: four male cases without associated adults labeled "Stamford, Conn.; June 11, 1931; B.T.R. Lab. Col.; from hollow apple tree; S.W. Bromley Collection 1955"; two male cases without associated adults labeled "Chautauqua Co., N.Y.; June 1934; collector S. Bromley; S.W. Bromley Collection 1955"; one male case with associated adult labeled " 9684g Hopk. U.S. "; one case with associated adult male labeled "Falls Church, VA.; reared May 11­14; C.T. Greene; Liriodendron ; 10490a Hopk. U.S.; C.T. Greene Collector"; two male cases with associated adults labeled " Falls Church, VA; May 10­15; Liriodendron tulipifera ; 12957 Hopk. U.S.; reared C.T. Greene; T.E. Snyder Colr."; one female case with associated adult labeled "Falls Church, Va., reared May 26­14, Liriodendron , 10490a Hopk. U. S., C.T. Greene, colr., C. T. Greene"; one female case with pinned adult labeled “Fleetwood, N.Y.; May 14­33; C.L. Ragot; larva taken in decayed stump May 14, emerged on May 19­33; S.W. Bromley Collection 1955"; one female case with pinned adult labeled "Westerleigh, N.Y.; VI­12­1928; N.T. Davis; recently emerged from pupa skin in stump; S.W. Bromley Collection 1955"; and two male cases with pinned adults labeled "Ingham Co. [Michigan]; T2N R1E, S33, Danville State Game Area; on May 13, 1965; Norman Baker." The pupal case of this species was previously described by C.T. Greene (1917).

Description: Greatest length, including anterior antennal processes, ♂ 16.5–22.0 mm, ♀ 19.0– 20.5 mm; greatest width of thorax, ♂ 4.0–6.0 mm, ♀ 6.0 mm; greatest width of abdomen, ♂ 4.0–5.0 mm, ♀ 5.0– 5.5 mm, tapering to ♂ 2.0–3.0 mm and ♀ 3.0 mm at greatest width of abdominal segment 8. Integument subshining, dark golden brown; posterior part of wing and leg sheaths, head, dorsum of thorax, and anterior part of abdomen sometimes darker; spines and other processes glistening reddish brown, generally darker apically; bristlelike spines mostly uniformly reddish brown.

Head with pair of dorsally rounded, ventrally wedge­shaped, basally rugose, anterior antennal processes not joined at base, and group of 4 basally fused posterior antennal processes curving and becoming shorter posteriorly; inner posterior process longer than and separated from outer posterior processes by rounded to flat, smooth to rugose area; outer 2 posterior processes fused for greater distance than other processes. Facial area often rugose on each side of midline; some cases with 1–3 small spines and longer spine posterolateral to outer posterior antennal process. Labral, proboscial, and maxillary sheaths smooth and elongate. Proboscial sheath with slight median furrow and median posterior callosity or tubercle. Maxillary sheath extending about two­thirds length of proboscial sheath; pair of callosities or tubercles sometimes overhanging anterior coxal sheath lateral to longitudinal split of anterior coxal sheath.

Anterior coxal sheath smooth, with anterior, median, longitudinal split sometimes extending to posterior sheath margin. Prothoracic spiracle oval or round, situated midlaterally on small, reddish­brown, often rugose callosity at anterior margin of thorax. Anterior mesothoracic spines on side of thorax above base of mid leg sheath consisting of inner or anterior pair of short, basally broad, fused, posteriorly curved spines and single outer or posterior broad, straight spine widely separated from anterior pair. Posterior mesothoracic callosity slight, with short, broad, apically rounded and sclerotized posterior mesothoracic spine at base of wing sheath. Wing sheath smooth, with elongate grooves, lacking median or basal tubercles. Thoracic area above wing sheath smooth to slightly rugulose. Apex of hind leg sheath reaching middle or posterior portion of abdominal segment 3.

Abdominal spiracles oval or round, reddish brown, on slight swellings along midline laterally.

Abdominal segment 1 with dorsal transverse row of 34–52 short, stout spines; median pair of spines and some other spines longer than adjacent spines so that 3–8 short spines alternate with 1 longer spine; usually 6– 8 indistinct, short dorsolateral bristle­like spines on each side; 6–10 lateral bristle­like spines behind each spiracle; venter obscured by wing and leg sheaths.

Segments 2–5 with dorsal spines forming slight peak with 1–5 long spines at peak pointing anteriorly. Segments 2–7 with 28–52, 27–43, 21–37, 10–31 (usually 23–31), 11–17, and 6–16 (usually 10–16) spines, respectively. Segments 2–5 often with 3–8 short spines between long spines.

Segments 6–7 similar to segments 2–5 or with mostly long spines, often median pair of short spines farther apart than on other segments.

Segments 2–7 with 5–15 dorsolateral bristle­like spines on each side, posterior segments usually with fewer spines; 4–12 lateral bristle­like spines behind each spiracle consisting of 2–3 longer and thicker bristlelike spines, mostly toward venter, alternating with short, thin bristle­like spines and 1–3 short, thin outer bristle­like spines especially toward dorsal surface. Segment 7 with lateral bristle­like spines of about equal length and thickness.

Segment 2 with 6–14 ventral bristle­like spines on each side of and extending under hind leg sheath. Segments 3–7 with ventral transverse row of 14–32 bristle­like spines; spines becoming longer and thicker on posterior segments; some bristle­like spines shorter than others; sometimes 2 bristle­like spines issuing from common base. Segments 3–4 often with wider median space in ventral rows of bristle­like spines than more posterior segments.

Segments 8–9 curved downward. Segment 8 with 1 large, dorsal, sometimes bifurcate spine on each side of midline; small reddish­brown spiracle at lateral midline; lacking dorsolateral, lateral, and ventral spines. Segment 9 with pair of short dorsomedian tubercles, dorsal posterolateral processes curved toward midline, rugose, dorsally curved ventral posterolateral processes, and pair of very large ventral, posteriorly pointed, basally rugose tubercles in male.

Figures

FIGURES 6–7. Laphria thoracica Fabricius, abdominal segment 9, ventral view, 6. male, 7. female. Abbreviations: dpp = dorsal posterolateral process, vpp = ventral posterolateral process.