Prionolabis acanthophora ( Alexander, 1938 )

Podenas, Sigitas, Park, Sun-Jae & Aukštikalnienė, Hye-Woo Byun and Rasa, 2022, Prionolabis crane flies (Diptera: Limoniidae) of Korea, Journal of Species Research 11 (1), pp. 29-37 : 31-33

Prionolabis acanthophora ( Alexander, 1938)

Limnophila (Prionolabis) acanthophora Alexander, 1938: 157 ; 1940: 49-50.

Prionolabis acanthophora Savchenko, 1983: 57 ; 1989: 113; Oosterbroek, 2021.

General ( Fig. 1A ): Body coloration polished dark brown to black. Body length of male 6.5-10.0 mm, of female about 10 mm. Wing length of male 8.5-11.0 mm, of female 3.5 mm.

Head: Black, sparsely dusted with brownish, more heavily so in front, and covered with short yellowish setae. Eyes widely separated in both sexes, distance between eyes in male approximately equals to the length of both basal antennomeres taken together. Antenna ( Fig. 2A ) 2.1 mm long in male, reaching to about middle of prescutum in male if bent backwards. Scape elongate, nearly cylindrical, twice as long as pedicel, black, dusted with gray, covered with scarce erect black setae dorsally. Pedicel egg-shaped, dark brown, covered with black setae. Flagellum 14-segmented, entirely dark brown. Basal flagellomeres short, just slightly longer than wid- er, indistinctly swollen and covered with short yellowish pubescence on ventral face, distal flagellomeres slightly elongate, fusiform, apical segment large, 1.7 times as long as preceding. Three distal flagellomeres of female antenna subequal. Longest verticils up to 1.7 times as long as respective segment. Rostrum black, dusted with brownish. Palpus dark brown. Mouth parts rufous.

Thorax: Cervical sclerites dark brown to black. Thorax semi-polished, dark brown to black, covered with sparse brownish pruinosity dorsally, grayish pruinosity ventro-laterally. Pronotum large dark brown, dusted with brownish pruinosity, more heavily dorsally and covered with sparse erect brownish setae. Mesonotal prescutum dark brown, fronto-lateral margin lighter brown, longitudinal stripes missing, surface covered with erect yellowish setae. Tubercular pits missing, pseudosutural fovea wide and shallow. Central part of scutal lobe polished dark brown to black, margins brownish pruinose, area between lobes densely pruinose. Scutellum dark brown, pruinose, with few erect brownish setae along posteri- or margin. Mediotergite brown to dark brown, sparsely pruinose. Pleuron dark brown, pruinosity, more heavily ventrally. Male wing ( Fig. 2B ) slightly iridescent, translucent, with brownish tinge, yellowish at base and costal area, without any darker spots except brown elongate stigma. Veins brown, pale at wing base. Venation: Sc long, reaching wing margin slightly beyond branching point of Rs, sc-r before tip of Sc, at branching point of Rs. Radial sector long, arched at base. Free end of R 1 short, oblique, disappearing at wing margin. R 2 slightly before tip of R 1, indistinct. R 3 and R 4 slightly diverging towards wing margin, R 4 and R 5 nearly parallel to each other. Cell r 3 with very short stem. Discal cell elongate, 1.7 times as long as wide. Stem of cell m 1 1.25 times as long as cell itself. Cross-vein m-cu at about two-thirds of discal cell length. CuA slightly arched before wing margin, CuP straight, anal vein slightly sinuous. Anal angle long and wide, posterior margin widely rounded. Calypter without setae. Female wing reduced, unsuitable for flight. Length of male halter 1.5-1.7 mm. Stem of halter brownish with rusty brown base, knob pale yellow. Coxae dark brown, dusted with gray, covered with long yellowish setae. Meron small, thus second and third pairs of coxae close to each other. Trochanters brown, just posterior somewhat darker dorsally. Femur dark brown with narrowly yellowish base, wider on posterior pair. Tibia light brown with dark brown apex. Tarsus dark brown with lighter brown base of basal tarsomere. Male femur I: 5.0- 5.2 mm long, II: 5.0-6.0 mm, III: 6.0-7.0 mm, tibia I: 6.5-7.0 mm, II: 6.2-6.5 mm, III: 7.0-8.0 mm, tarsus I: 7.4-7.8 mm, II: 6.6-7.0 mm, III: 7.4-8.2 mm. Claw comparatively small and simple, without spines. Arolium reaching to beyond middle of claw.

Abdomen: Dark brown, tergites and sternites covered with yellowish setae. Paired transverse sutures on tergites indistinct. Male terminalia ( Fig. 2C, 2D ) concolorous with the rest of abdomen. Ninth tergite wider than longer, posterior margin with U-shaped medial incision. Gonocoxite slightly elongate, 1.7 times as long as width at base, simple, without additional lobes. Outer gonostylus sclerotized, with straight apical spine and point-apexed subapical lobe, additional fleshy and setose lobe starting at about one third on dorsal surface and reaching nearly to the tip of apical spine of the gonostylus. Inner gonostylus wider at basal half, narrowing towards blackened 5-toothed apical part and bearing small rounded setose lobe ventro-basally. Paramere yellow, with long stem and shaped like a very long shoe with raised apex and spinous heel. Aedeagus very long, narrows towards distal end, which is curved downwards. Ovipositor with elongate brown cerci and black hypovalvae.

Elevation range in Korea: Altitudes from sea level to nearly 1,200 m ( Alexander, 1940).

Period of activity: Adults are active and flying from mid-May through end of June ( Alexander, 1940) in Korea, from late May through late July in the Far East of Russia ( Savchenko, 1983).

Habitats: Unknown in Korea. Among dense grassy vegetation that covers small water pools surrounded by forests, along forest roadsides, on margins of streams and rivers in the Far East of Russia ( Savchenko, 1983).

General distribution: North Korea and the Far East of Russia.

Examined material ( Fig. 6A ): holotype (as Limnophila (Prionolabis) acanthophora ), male (antenna, fore leg, wing and genitalia slide mounted), North Korea, Ompo, alt. 150 ft. [46 m], May 29, 1938, A. M. Yankovsky ( USNM); 4 males (pinned), North Korea, Ompo, alt. 750 ft. [229 m], May 16, 1938, A. M. Yankovsky ( USNM) ; metatype, male (antenna, leg, wing and genitalia slide mounted), North Korea, Ompo , alt. 900 ft. [274 m], May 19, 1938, A. M. Yankovsky ( USNM); 1 male (pinned), North Korea, Ompo, alt. 800 ft. [244 m], May 21, 1938, A. M. Yankovsky ( USNM); 1 male (pinned), North Korea, Ompo, alt. 400 ft. [122 m], May 23, 1938, A. M. Yankovsky ( USNM); 1 male (pinned), North Korea, Ompo, alt. 200 ft. [61 m], May 24, 1938, A. M. Yankovsky ( USNM) .

Figures

Fig. 1. Sexual dimorphism in Prionolabis Osten Sacken, 1860. A. male of P. acanthophora (Alexander, 1938). B. female of P. hospes (Egger, 1863). Scale bars: 1.0 mm.

Fig. 2. Prionolabis acanthophora (Alexander, 1938), male. A. an- tenna. B. wing. C. male genitalia in glycerol, dorsal view. D. male genitalia slide-mounted, dorsal view, Alexander’s metatype. Scale bars: 0.5 mm (A, C, D), 1.0 mm (B).

Fig. 6. Distribution maps of Korean Prionolabis. A. P. acanthophora. B. P. clavaria. C. P. dis. D. P. yankovskyana.