Rhamphomyia (Dasyrhamphomyia) erinacioides Malloch

Rhamphomyia (Dasyrhamphomyia) erinacioides Malloch

(Figs 5–7)

Rhamphomyia erinacioides Malloch, 1919: 45. Type-locality: Camden Bay, Alaska, USA.

Other references: Melander, 1928: 194 (catalogue); Melander, 1965: 463 (catalogue); Danks, 1981: 465 (arctic insects); Cooper & Cumming, 1993: 32 (type catalogue); Yang et al., 2007: 194 (catalogue).

Rhamphomyia (Rhamphomyia) erinacioides Malloch: Shamshev, 2016: 75 (checklist).

Type material examined. HOLOTYPE ♂ (Fig. 5A), labelled (Fig. 5B): “ HOLOTYPE / Rhamphomyia / erinaci- oides Mall./ CNC No. 215 [red label]”; “W. of Kangenevik [Konganevik]/ Camdin [Camden] Bay/ Alaska July, 4 [1914]”; “Canadian/ Arctic/ Expedition/ F.J. [F. Johansen] 1914”; “ Rhamphomyia / erinacioides/ Mall—type [hand written]” (CNC). PARATYPE: “ PARATYPE / Rhamphomyia / erinacioides/ Mall./ No. 215 [yellow label]”; “Barter Isl. [Alaska]/ arctic”; “D. Jenness/ Coll.”; “Canadian/ Arctic/ Expedition/ July 11, 1914 ” (1 ♂, CNC).

Diagnosis. This species is distinguished from other Dasyrhamphomyia by the dichoptic male, body densely clothed in black setae, tibia with dense white ventral pile and anteroventral row of peg-like setae, hind femur with long basal anteroventral setae, apical half without setae, and male cerci reddish brown.

Redescription. Wing length 4.8–5.0 mm. Male. Head dark brown in ground-colour, with faint pruinescence on face, frons, postgena and occiput; oral margin dark and lustrous. Dichoptic, eyes separated by nearly width of ocellar triangle, frons divergent towards antennae; eyes with ommatidia equal-sized throughout. Face divergent towards mouthparts, with oral margin dark and shiny. Ocellar triangle dark, with numerous setae. Postocular and occipital setae undifferentiated, numerous and long. Postgena with many hair-like, long, dark setae. Antenna dark; scape slightly longer than pedicel; postpedicel cone-like, less than 2X longer than basal width; stylus subequal to basal width of postpedicel. Palpus dark, with many dark, long setulae. Proboscis dark; clypeus with glossy upper margin, pruinescent apically; labrum lustrous and reddish brown, length nearly twice eye height.

Thorax dark brown in ground-colour, with faint pruinescence, dark setose; spiracles dark. Proepisternum with many long, hair-like setae, including in front of anterior spiracle; prosternum bare. Antepronotum with row of short setae. Postpronotum clothed with numerous long setae. Scutum densely clothed with long setae; acr 2–4 serial, subequal in length to dc; dc 4–5 serial, increasing in length posteriorly; presut spal and psut spal clothed in long, 3–4 serial setae, similar to dc; numerous notopleural setae, similar to dc; pal with 5–6 setae; 10 pairs of marginal sctl. Laterotergite with cluster of long setae.

Legs reddish brown. Coxae with numerous dark, fine anterior setae. Fore and mid femora clothed in long, thin setae, forming anteroventral and posteroventral rows. Hind femur with long anterodorsal and posterodorsal setae; anteroventral setae confined to basal half, apical half bare; posteroventral setae confined to basal 1/4, remaining apical ¾ bare (Fig. 6C). Tibiae with dense ventral white pile and anteroventral row of minute, black peg-like setae; posterodorsal row of fine setae, not longer than width of tibia. Hind tibia with 1 short seta in posteroapical comb. Tarsomere 1 on all legs slender, unmodified, narrower than corresponding tibia at apex.

Wing lightly infuscate with yellowish veins; CuA+CuP faint, extending to wing margin. Basal coastal seta absent; pterostigma faint. Anal lobe well-developed; alular incision right angled. Halter dark.

Abdomen concolourous with thorax; densely clothed in long, dark setae; undissected, tergite and sternite 8 not examined.

Terminalia (Figs 6A, B) (undissected) large, brown. Epandrium bearing triangular posterior projection, densely pruinescent medially. Cercus reddish brown, directed anteriorly, rather long, with apex extending to segment 5; cerci fold over each other on apical third.

Female (first description). Head as in male, but frons even slightly broader, postpedicel somewhat longer, setation on occiput and palpus shorter. Thorax as in male, but scutum with short setation. Legs colour as in male. Coxae with same setation, but less numerous and somewhat shorter setation than in male. Fore and mid legs as in male. Hind femur entirely subshiny, faintly greyish pollinose and entirely covered with ordinary setae (sparser along middle anteriorly, somewhat longer anteroventrally and posteroventrally), with hardly prominent usual pubescence ventrally; hind tibia of usual thickness, slender throughout, entirely covered with ordinary short setae, not pubescent ventrally; hind tarsomeres entirely covered with ordinary short setae, not pubescent ventrally. Wing of same shape as in male, uniformly faintly brownish infuscate.Abdomen somewhat lighter pollinose, rather brownish, with greatly reduced setation, covered with uniform very short black to brown bristly hairs longer on tergites 1–2 laterally; cercus concolorous with abdomen, long, slender.

Distribution. In North America, this species is recorded only from the type series on Barter Island in Camden Bay, Alaska and also from the nearby mainland coast (Fig. 7). In addition, R. erinacioides is reported from several localities widely distributed across northern Russia (Shamshev 2016). This distribution pattern in the low arctic is termed “southern arctic—western” by Danks (1981, fig. 65), for tundra species of the coastal plain, reaching as far east as Herschel Island or Mackenzie Delta.