Elachiptera aquila Wheeler

Wheeler, Terry A., 2003, A new brachypterous species of Elachiptera Becker (Diptera: Chloropidae) from freshwater wetlands in eastern Canada, Zootaxa 360, pp. 1-6 : 2-4

Elachiptera aquila Wheeler , sp. nov.

( Figs. 1–5 )

Diagnosis.— Elachiptera aquila can be distinguished from other described Nearctic species of Elachiptera by the combination of broadly rounded occipital margin, the medially microtomentose scutum and infuscated wings not extending to the apex of the abdomen. See also the revised key couplets in Comments.

Description.— Total length 2.5–3.3 mm. Posterior margin of head broadly rounded in dorsal view ( Fig. 2 ); frons dark yellow­brown, paler anteriorly, frontal triangle shining black, ocellar tubercle microtomentose; antenna dark yellow, arista black, straplike basally, but not as broad as in some other species of the genus, narrowing evenly at apex ( Fig. 3 ); face black, gena black, with oblique striations ventral to eye, genal height 0.3 – 0.35 x eye height, long axis of eye oblique; postgena broad, convex, postgena and occiput densely microtomentose; palps yellow.

Scutum black, densely microtomentose medially between dorsocentral lines, shining laterally except for notopleuron, scutum without incised longitudinal lines, but setulae apparently arising from small tubercles, especially medially; scutellum rounded posteriorly, densely microtomentose, flat and rugose dorsally, apical and subapical setae arising from short tubercles; thoracic pleurites polished black except along dorsal margin from notopleuron to laterotergite and posterior half of meron. Legs, including coxae, mostly bright yellow, fore tibia and fore tarsus dark brown, apical half to two­thirds of hind femur and entire hind tibia brown, mid tibia sometimes dark yellow. Wing length 1.4–2.0 mm, extending to posterior margin of abdominal tergite 4 in most specimens, as far as posterior margin of tergite 5 in two specimens; kink in CuA1 not as evident as in other Chloropidae , wing membrane fuscous anterior to M1+2 and distal to R1, and around CuA1 ( Fig. 1 ). Halter yellow.

Abdomen dark, syntergite 1+2 approximately twice as long as tergite 3.

Male genitalia: Epandrium dark brown with short bristles; surstylus widest in basal third, evenly narrowed distally, recurved ( Fig. 4 ); hypandrium relatively broad and short in lateral view; postgonite broadly triangular in ventral view, broadly rounded in lateral view, with sensillae and scattered setulae ( Fig. 4 ); phallapodeme short, curved, phallus long, membranous ( Fig. 4 ); cercus broad, rounded, with single long ventral bristle, cerci separated by wide, V­shaped median cleft ( Fig. 5 ).

Type material.— Holotype ♂. CANADA: Quebec: Lac St­Francois Nat. Wildl. Area, Marais Fraser (45°02.37'N, 74°27.73'W), Carex meadow, pan trap, 14–20.v.1999, F. Beaulieu (LEM). Paratypes: 1 ♂, same data as holotype except 26.v–03.vi.1999 (LEM); 1 ♀, same except 0 3–11.vi.1999 (LEM); 1 ♀, same except 45°02.40'N, 74°28.03'W, 21– 28.viii.1999 (LEM); 1 ♀, Ontario: Crieff Bog, 3 km W Puslinch, 20–26.vi.1987, pantrap, sedge meadow, D. Blades (DEBU); 1 ♀, Crieff Bog, 3 km W Puslinch, 21–27.v.1987, pantrap, sedge island, D. Blades (DEBU); 1 ♀, Wylde Lake Bog, 8 km E Arthur, 7–25.v.1988, pantrap, sedge meadow hollow, D. Blades (DEBU); 1 ♀, Gibson Lake, 6mi E Go Home Bay, 06.v.1959, J.G. Chillcott (CNC).

Etymology.— The species name is from the Latin aquila (dark) referring to the appearance of the wings.

Comments.— This species was referred to as Elachiptera sp. nr. salinaria by Blades and Marshall (1994) and Beaulieu and Wheeler (2001).

The only other described Nearctic species of Elachiptera with a broadly rounded occipital margin is E. salinaria . Sabrosky and Valley (1987) revised Sabrosky’s (1948) key to Nearctic Elachiptera to accommodate E. salinaria , and E. aquila can be included in that revised key by replacing their couplet 20 with the following:

20. Occiput convexly developed, back of head well rounded in dorsal view................. 20a ­ Occiput not convexly developed, back of head straight or barely rounded in dorsal view ..................................................................................................................................... 21 20a.Scutum shining medially with three rows of distinct punctures, microtomentose along dorsocentral lines, lateral and posterior margins. Wing hyaline to pale fuscous, fully developed. Epandrium yellow. Salt marsh species ....................... Elachiptera salinaria ­ Scutum evenly microtomentose medially. Wing dark fuscous anteriorly, short, not extending to apex of abdomen. Epandrium brown. Freshwater wetland species ........... .......................................................................................................... Elachiptera aquila

Figures

FIGURES 1 – 5. Elachiptera aquila. 1. Wing; 2. Head (dorsal); 3. Antenna (lateral); 4. Male genitalia (lateral); 5. Male genitalia (posterior). Abbreviations: cer — cercus; epd — epandrium; hyp ­ hypandrium; phap — phallapodeme; phal — phallus; pog — postgonite; sur — surstylus. Scale bar = 0.1 mm (Figs. 4 ­ 5)