Liancalus pterodactyl Runyon & Hurley

Runyon, Justin B. & Hurley, Richard L., 2015, A revision of the Nearctic species of Liancalus Loew (Diptera, Dolichopodidae), ZooKeys 483, pp. 97-147 : 118-121

Taxon classification Animalia Diptera Dolichopodidae

Liancalus pterodactyl Runyon & Hurley sp. n. Figs 1, 2D, 3A, 4A, 7, 11A, 13, 16A

Diagnosis.

Males are most similar to Liancalus hydrophilus but have a longer, more slender setae-bearing lobe on posteroapical wing margin (Figs 4, 7). Cerci of male Liancalus pterodactyl have long setae confined mostly to apical half (Fig. 2D), whereas Liancalus hydrophilus has long, evenly-spaced setae along the full-length of the cerci (Fig. 8). Females are distinguished by the dorsal one-quarter or more postcranial hairs dark brown to black (other Nearctic species have at most a few dark hairs).

Description.

Male. Body length 9.0-12.0 mm, wing length 7.5-8.5 mm. Head: Face nearly parallel-sided on dorsal half, widening toward clypeus; frontoclypeal suture near mid-face, distinct; eyes with short hairs between facets; face green-bronze (more green immediately below antenna) with silver pollen most noticeable along eyes and on ventral half of face; ommatidia essentially the same size throughout. Vertex concolorous with face, usually with dense silver pollen. Vertical setae on small elevation; ocellar tubercle prominent with 2 large setae (subequal in size to vertical setae); with 2 postocellar setae which are two-thirds length ocellar setae; postocular setae approximately half length of vertical setae with dorsal two-thirds of postocular setae black (approximately 20 black setae), ventral third (approximately 10 setae) white and more slender and slightly longer than other postocular setae. Ventral postcranial hairs (beard) abundant, white with dorsal third to one-quarter black. Palpus black, covered with silver pollen and sparse black hairs. Antenna (Fig. 1) black, first flagellomere about as long as wide, rounded apically, arista inserted near midpoint of dorsal edge.

Thorax: Scutum blue-green with bronze stripes between acrostichal setae and dorsocentral setae, and along intra-alar setae; scutellum and posterior slope of scutum blue-green, posterior slope of scutum sometimes with bronze medially; notopleuron and postpronotum (humerus) covered with dense silver pollen, usually with some blue-green reflections; usually 6-10 dorsocentral setae; 8-14 long acrostichal setae (≥ 2/3 length of dorsocentral setae), in a single row; 2 notopleural setae; postpronotum with 1-2 strong setae and often a few smaller hairs or setae; 2 presutural intra-alar setae; 1 presutural and 2 postsutural supra-alar setae; 1 postalar seta; scutellum blue-green with 8 (rarely 9) large marginal setae (4 per side), no additional hairs; proepisternum with 1 dorsal and 1 ventral tuft of white hairs. Pleura metallic green-bronze, covered with dense silver-gray pollen, without setae or hairs (Fig. 1).

Legs: Legs concolorous with pleura. Coxa I (Fig. 1) uniformly covered with white, slender hairs on anterior surface (length of hairs subequal to width of coxa I), with a few black, slender setae at apex. Coxa II with white hairs anteriorly, a couple black setae near apex, and a black ad seta just beyond 1/2. Coxa III with scattered white hairs and a black dorsal seta near 1/2. Femur I with sparse white hairs on ventral surface (length ≤ width of femur). Femur II with row of short (≤ width of femur) posterior to pv setae on distal half, those near middle of femur white, longest and becoming black and shorter apically; with a row of very short black ad setae preceding usual preapical seta. Femur III with scattered white hairs (length ≤ width of femur) on dorsal and posterior surface at base. Tarsus I(2) short (length subequal to width), slightly thickened, with ventral brush of setulae (Fig. 3A). Ratios of tibia:tarsomeres for leg I: 18-7-2-5-3-2; for leg II: 26-22-7-4-2-2; for leg III: 38-17-13-4-2-2.

Wing (Figs 4A, 7): Hyaline, with light brown clouding between R2+3 and R4+5 apically, most distinct along veins; with a longitudinal spurious vein immediately above M1 that ends near junction of M1 with dm-cu; apical part of membrane between R4+5 and M1 with a narrow, translucent area that is white in certain lights and enclosed within a small, brown cloud (Fig. 7). Fourth costal sector (between R4+5 and M1) flattened with a cluster of 3-4 long, black setae at apex of M1 that are usually fused apically; wing margin between M1 and CuA1 with a long (length> 3 × width), slender, finger-like projection bearing several black setae at apex. Calypter yellow with a fan of long, pale yellow setae at apex. Halter pale yellow (Fig. 1).

Abdomen: Cylindrical, elongate (Fig. 2D); T1 metallic blue-green, covered with dense silver pollen. T2-T4 mostly metallic blue-green with silver pollen, with apical one-third bronze, usually bronze dorsally at base. T5 dark bronze with metallic green dorsally and sparse silver pollen. T6 dark metallic blue-green with sparse to moderate silver pollen. T1-T3 with long, white hair laterally, longest on T1 and T2. Sternites bronze with sparse silver-gray pollen. S1 bare except for lateral tuft of white hairs at extreme base. S2 and S3 with sparse long, white hairs. S4 mostly bare. Hypopygium (Fig. 11A): cerci as long or longer then abdomen, slender, cylindrical, with pale yellow setae on ventral surface that are most dense and longest on apical half (Fig. 2D).

Female. Body length 7.5-9.0 mm, wing length 7.0-7.5 mm. Similar to male except for face wider; palpus covered with golden brown pollen, with denser, black setae. Femur I with pd row of black setae/hairs and relatively long (subequal to width of femur), white hairs on ventral and posterior surface. Femur II with pale hair on posterior surface extending nearly to base; tarsus I(2) normal, not unusually short or thickened. Wing (Fig. 16A) hyaline, of normal shape; with diffuse brown clouding immediately above M1 before junction with dm-cu, this clouding often continuing posteriorly into cell bm+dm.

Etymology.

The epithet, a noun in apposition, is in reference to the large size of this species - reminiscent of the large pterosaurs from the Jurassic; and the Greek pteron "wing" + daktylos "finger" in reference to the finger-like lobe on the wing (Fig. 4A).

Remarks.

This is perhaps the largest species of Dolichopodidae , at least in terms of body length.

Distribution.

This species occurs in the Northern Rocky Mountains of U.S. and neighboring Canada; one male was collected in the Trinity Alps of northern California (Fig. 13).

Type material.

HOLOTYPE ♂, labelled: "MONTANA: Gallatin Co./ Grotto Falls 7000'/ 22 mi S Bozeman/ 19-VIII-2001/ J. B. Runyon"; "HOLOTYPE/ ♂ Liancalus / pterodactyl / Runyon & Hurley" [red label] (MCZ). PARATYPES:CANADA.Alberta: Lake Louise, 30.x.1923, Eric Hearle (1 ♂, CNC), Banff, 6.x.1926, Eric Hearle (1 ♂, CNC). British Columbia: Robson, 13.iii.1957, H.R. Foxlee (3 ♀, UBCZ), same as previous, 14.iii.1957 (1 ♀, UBCZ), same as previous, 18.iii.1957 (1 ♀, UBCZ), same as previous, 17.x.1961 (1 ♀, UBCZ). USA.California: Trinity Co., Siligo Mtn, 7000 ft, 11.viii.1967 (1 ♂, CAS). Idaho: Bonner Co., 14 mi. NW Samuels, 26.ix.1969, W.F. Barr (1 ♀, WSU). Montana: Flathead Co., seep on Going to the Sun Rd nr Haystack Crk, Glacier NP, 22.ix.2003, J. Giersch (1 ♂, MTEC), Cattle Queen Crk at Highline Trail, Glacier NP, 48.832221, -113.799051, 1845 m elev, 11.ix.2012, J. Giersch (1 ♂, MTEC); Gallatin Co., Bozeman, 3.ix.1960, S. Wiegand (1 ♂, MTEC), Silken Skein Falls, 3 mi. S Hyalite Rsvr., 8333 ft, 11.viii.2000, JBR (1 ♂, MTEC), Palisade Falls, 1 mi. S Hyalite Rsvr., 7685 ft, 12.viii.2000, RLH & JBR (1 ♂, 2 ♀, MTEC), same as previous, 19.x.2000, JBR (2 ♂, MTEC), same as previous, 20.iv.2002, JBR (1 ♀, MTEC), same as previous, 20.viii.2009, JBR (3 ♂, 1 ♀, MTEC), same as previous, 12.x.2012, JBR (1 ♂, MTEC); Glacier Co., Cracker Lake inlet far West stream, Glacier NP, 48.742317, -113.651581, 1845 m elev, 9.ix.2011, J. Giersch (1 ♂, MTEC).