Hilara galactoptera, Frey, 1935: 7

Shamshev, Igor V., 2020, Notes on species of Empididae (Diptera) described by R. Frey from the Swedish Kamchatka Expedition 1920 - 1922, Zootaxa 4758 (3), pp. 532-548 : 539-541

galactoptera Frey, 1935: 7 ( Hilara , nec Strobl, 1910)

Current name. Hilara lactescens Frey, 1955b .

Type locality: Russia, Kamchatka .

Notes on the type series. Frey described this species after the male sex only. He noted the following material: “ 1 ♂, Kamchatka ” .

Type material examined: HOLOTYPE, ♂ ( Fig. 12 ), labelled ( Fig. 13 ): “ Kamtschatka / Malaise ”; “Spec. typ.”; “ Hilara / galactoptera / n. sp. [hand-written by Frey ] R. Frey det.”; “ Holotypus / Hilara / galactoptera Frey, 1935 [our red label]”; “ Hilara / lactescens Frey, 1955 [our identification label]” ( NHRS).

Diagnosis. Rather mid-sized species of the H. litorea group, distinguished from other species of this group by the following combination of characters: occiput greyish, mesoscutum almost uniformly ash grey pruinose, acrostichal setae biserial, legs almost uniformly dark brown, only “knees” yellowish, fore basitarsus strongly thickened, wing somewhat whitish, halteres brownish, abdominal tergites 1–3 with pale setae.

Re-description. Male ( Fig. 12 ). Body length 3.8 mm, wing length 4 mm. Head ( Fig. 14 ) black. Frons and face equally broad, dark greyish in anterior view, somewhat paler in dorsal view; frontal seta very long, strong. Ocellar triangle concolourous with frons, pair of ocellar setae nearly as long as frontals. Occiput slightly shrunken on upper part; rather dark greyish viewed dorsally, entirely densely light grey pruinose viewed laterally; with black setae, upper postoculars long. Antenna entirely black; postpedicel 1.8 times longer than wide; stylus long, only slightly shorter than postpedicel. Palpus pale brownish; with 1 very long, black, ventral seta on apical part and some numerous fine setulae ventrally. Proboscis somewhat elongate, labrum 1.3X shorter than eye height.

Thorax ( Fig. 14 ) black; almost uniformly ash grey pruinose, with black setae (except noted); scutum only with indications of some darker vittae between acrostichals and dorsocentrals (dorsal view). Prosternum covered with pale minute setulae. Proepisternum with pale minute setulae on lower part; 1 long, fine yellowish seta on upper part of proepisternum in front of anterior spiracle. Antepronotum with 1 long, strong, black seta laterally and 3 setulae dorsally. Postpronotal lobe with 1 moderately long black seta and some intermixed pale and black minute setulae. Mesonotum with 1 presutural intra-alar, 1 longer presutural supra-alar, 3 notopleurals (anterior seta brownish yellow and shorter, situated somewhat aside; in addition, notopleuron with several yellowish to yellowish brown short fine setae), 2 postsutural supra-alars (posterior seta longer; with 1–2 additional setulae), 1 very long and 1 minute postalars; 4 scutellars (apical pair longer); acrostichals short, fine, arranged in 2 close irregular rows; dorsocentrals uniserial, somewhat longer than acrostichals, prescutellars longer (prescutellar area obscured by pin). Anterior and posterior spiracles brown.

Legs almost uniformly dark brown, only “knees” yellowish; coxae densely, remaining parts faintly greyish pruinose. Fore coxa with short pale fine setae anteriorly and several long dark setae apically. Fore femur with rows of short anteroventral and posteroventral setae. Mid femur with complete row of several long strong anterodorsal setae; rows of long fine anteroventral and posteroventral setae. Hind femur with row of moderately long strong setae dorsally, rows of finer moderately long anteroventrals and shorter posteroventrals. Fore tibia slightly thickened toward apex; 1 short fine posterodorsal seta near apex, several fine setae of subapical circlet. Mid tibia some scattered short setae, 1–2 short anterodorsals, 2 posterodorsals, 2 anteroventrals. Hind tibia with some short setae dorsally. Fore basitarsus strongly thickened, about twice as long as wide, nearly 3/4 of fore tibia length (slightly shrunken on both legs); without long setae; mid and hind basitarsi slender, covered with only usual setulae.

Wing membrane somewhat whitish; veins mostly pale yellowish, only costa darker; pterostigma indistinct; 1 long, dark basal costal seta present. Anal vein (CuA+CuP) incomplete; radial fork rather shortened. Axillary incision acute, anal lobe well-developed. Squama yellow, pale fringed. Halter brownish.

Abdomen brownish, faintly greyish pruinose, somewhat lustrous; tergite 1 with pale setae, tergites 2–3 with intermixed pale and dark setae, remaining tergites with dark setae; tergal posteromarginal setae distinct, moderately long. Terminalia (not dissected) rather small, dark brown, faintly greyish pruinose, with blackish short fine setae, not extending beyond pregenital segments. Hypandrium with even, rather narrow curvature (lateral view).

Female. Unknown.

Distribution. Palaearctic: Russia (Kamchatskiy Territory).

Remarks. Hilara lactescens belongs to the H. litorea group and within the key to Hilara of Fennoscandia ( Chvála 2005) this species runs to H. litorea (Fallén) . The male of H. lactescens differs from the male of H. litorea primarily by uniformly greyish mesoscutum (vs. broadly brownish medially) and biserial acrostichal setae (vs. 4- serial).

Figures

FIGURES 12–14. Hilara galactoptera Frey (= H. lactescens Frey). 12. male habitus, holotype, lateral view; 13. holotype labels; 14. male head and thorax, holotype, anterodorsal view.