Efferia aestuans (Linnaeus)

Dennis, D. Steve, Barnes, Jeffrey K. & Knutson, Lloyd, 2008, Pupal cases of Nearctic robber flies (Diptera: Asilidae), Zootaxa 1868 (1), pp. 1-98 : 71-73

Efferia aestuans (Linnaeus)

( Fig. 44)

Descriptions of the pupae of Efferia aestuans were given in Bromley's (1946) key to Connecticut robber fly pupal cases and by Malloch (1917) and Riley (1870). Although Malloch's (1917) description of a male pupal case is fairly complete, it is not presented in a style parallel to ours. We therefore redescribe this species utilizing both male and female material.

This description is based on five pupal cases with associated, pinned adults from the United States National Museum; two male cases are labeled "Lockport, N.Y.; 12 July 1945; L.L. Pechuman; from larva in garden soil; S.W. Bromley Collection 1955," and "E. Baton Rouge Par.; Hylandia Road; 18 July 1969; Mac Tidwell; reared from pupae, emerged 28 July 1969." Three female cases are labeled "Lockport, N.Y.; 24 July 1945; L.L. Pechuman; from larva found in garden soil; S.W. Bromley Collection 1955," "Acc. 15.4; Tidwell; Idlewild Ex. Farm; E. Feliciana Par.; 7 April 1965; reared from larvae, pupated 8 July, emer. 6 Aug," and "Stamford, Conn.; July 15, 1929; B.T.R. Lab.; Col. S.W. Bromley Collection 1955."

Description: Greatest length, including anterior antennal processes, ♂ 14.5–18.5 mm, ♀ 16.5–17.5 mm; greatest width of thorax, ♂ 4.0 mm, ♀ 4.0– 4.5 mm; greatest width of abdomen, ♂ 3.0– 3.3 mm, ♀ 3.5–4.3 mm, tapering to ♂ 1.3 mm and ♀ 1.0– 1.5 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 uniformly colored dorsal abdominal spines; bristle­like spines yellowish to reddish brown.

Head with pair of dorsally flattened, ventrally wedge­shaped anterior antennal processes not joined at base and group of 3 basally fused 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 usually broad, with outer flattened area basally; inner and middle posterior processes narrow, acute to slightly rounded apically, with middle posterior process sometimes smaller than inner process. Labral sheath smooth to rugose, usually with a slight apical keel. Proboscial sheath smooth to rugose on each side of midline, with small, rugose, ridge­like tubercle on each side of midline and small, ventrally concave, median tubercle posteriorly. Maxillary sheath rugose on inner margin, with small posterior tubercle; sometimes with minute, yellowish tubercle just above anterior margin of proboscial sheath on each side of labral sheath.

Anterior coxal sheath irregularly rugulose, with anterior, median, longitudinal split; sometimes with minute anterior tubercle on each side of midline directly posterior to small lateral tubercles of proboscial sheath. Prothoracic spiracles elongate­oval, slightly upraised, situated midlaterally at anterior margin of thorax. Anterior mesothoracic spines consisting of pair of long, posteriorly curved, pointed spines above base of sheath of mid legs; posterior spine wider basally than anterior spine. Posterior mesothoracic callosity medium sized, smooth to slightly rugulose, with small, apically rounded posterior mesothoracic spine. Wing sheath irregularly rugose, lacking basal tubercles. Thoracic area above wing sheath smooth to irregularly rugose. Apex of hind leg sheath reaching to middle of abdominal segment 3.

Abdominal spiracles semi­oval, upraised, situated along midline laterally.

Abdominal segment 1 with dorsal transverse row of 12–13 long, apically recurved spurs, outermost spur on each side sometime very short; dorsolateral bristle­like spines absent; 3 bristle­like spines behind each spiracle; venter obscured by wing and leg sheaths.

Segments 2–7 with dorsomedian transverse row of 6 long spurs alternating with 8–14 short spines; spines broad, slightly in front of long spurs, sometimes bifurcate apically; 4–8 long dorsolateral bristle­like spines and 5–8 lateral bristle­like spines behind each spiracle; some dorsolateral spines bifurcate or trifurcate; lateral spine toward dorsum and some other lateral spines about one­half as long as surrounding spines.

Segment 2 with 7–11 long, apically recurved ventral bristle­like spines on each side of and extending under hind leg sheaths; segments 3–7 with complete transverse row of 20–31 long, straight to apically recurved ventral bristle­like spines.

Segment 8 with 2 dorsal spurs on each side of dorsal midline; small dark­brown spiracle at lateral midline; and 5–6 lateral bristle­like spines on each side; venter of female with 3 long bristle­like spines on each side of and curved toward ventral midline; male cases with 4–6 bristle­like spines on each side of midline and 1–2 median bristle­like spines.

Segment 9 with pair of long, straight to slightly apically recurved dorsal posterolateral processes; pair of short ventral posterolateral processes not fused to but curved toward dorsal posterolateral processes; and pair of small posteroventral and posteromedain tubercles; males with pair of large, widely separated, acuminate anteroventral tubercles.