Antocha (Antocha) gracillima Alexander, 1924b

Podenas, Sigitas & Young, Chen W., 2015, Antocha crane flies from Taiwan (Diptera: Limoniidae: Limoniinae), Zootaxa 4048 (4), pp. 523-537 : 526-528

Antocha (Antocha) gracillima Alexander, 1924b

( Figs. 3–5 )

Antocha (Antocha) gracillima Alexander, 1924b:67 ; Alexander, 1954:289; Savchenko & Krivolutskaya, 1976:111; Savchenko, 1983:106; Torii, 1992:175; Podenas & Byun, 2013:175 ; Oosterbroek, 2015.

Diagnosis. This is a medium-sized crane fly. General body coloration brownish gray to dark brown. Wings milky. Wing stigma light brown, rather indistinct in Taiwanese specimens, but distinct in specimens from Japan and Korea. Posterior margin of ninth tergite of male genitalia slightly sinuous without projections. Outer gonostylus blackened distally, tip split by small emargination with narrow inner bump and wide outer bump. Ovipositor with smooth, long, nearly parallel-sided and slightly arched cercus ( Podenas & Byun, 2013).

Description. Based on dry-mounted males. Body length: Males 3.5–3.9 mm. Wing length: Males 5.1–5.8 mm.

Head. Head brown dorsally, lighter along eye margin and covered with dense gray pruinosity. Antenna 16– segmented, 0.83–1.48 mm in males. Scape nearly cylindrical, yellowish brown. Pedicel brown, wider distally, narrower basally. Flagellum brown to dark brown. Flagellomeres oval, tapered toward apex. Distal flagellomere smaller than preceding segment. Verticils shorter than respective segments, slightly longer than whitish pubescence covering flagellomeres. Rostrum brownish yellow, covered with scarce grayish pruinosity. Palpus brown.

Thorax. Generally brown with yellowish pleuron, covered with gray pubescence, denser on dorsal part. Antepronotum brown medially, yellowish laterally. Mesonotal prescutum grayish yellow with three confluent brown stripes. Median stripe broad, split longitudinally by narrow light median vita. Mesonotal scutum brown, hardly visible through dense gray, bluish-gray pruinosity. Scutellum with light brown median line and dark brown lateral parts, ground color nearly invisible through dense gray pruinosity. Mediotergite light brown, darker frontally with dark brown median line and covered with gray pruinosity, which is less dense compare to scutellum. Pleuron generally light brown, with indistinct darker and lighter spots. Pronotum laterally yellow, katepisternum ventrally dark brown. Wing subhyaline, milky. Stigma light brown, distinctly lighter than in specimens from Japan and Korea. Wing venation typical for subgenus: discal cell closed, elongate, Rs very long and straight, anal angle big and nearly right-angled. Stem of haltere yellow with whitish base. Knob slightly infuscated. Haltere 0.75–0.88 mm long in males. Coxae yellow just frontal coxa slightly infuscated frontally. Trochanters yellow with narrowly darkened distal margin. Legs obscure yellow to light brown. Tips of segments slightly infuscated. Distal ends of tarsi brown. Male femur I: 4.0– 4.3 mm long, II: 4.25–4.60 mm, III: 4.9–5.3 mm; tibiae I: 4.7–4.9 mm, II: 4.4–4.8 mm, III: 5.5–5.8 mm; tarsus I: 4.0– 4.5 mm, II: 3.5–4.3 mm, III: 3.9–4.5 mm long. Claw with a single, very slender subbasal spine.

Abdomen. General color of abdomen brown. Five frontal segments somewhat lighter, brown, distal segments dark brown. Lateral and posterior margins of tergites and sternites grayish. Abdomen covered with sparse light erect setae.

Hypopygium. Male genitalia brownish yellow. Ninth tergite ( Fig. 3 ) simple, without additional lobes or structures, posterior margin nearly smooth, or slightly wavy. Gonocoxite ( Fig. 4 ) elongate, oval, no extra lobes. Outer gonostylus slightly arched, blackened toward apex, bearing two small bumps at apex. Inner bump distinctly narrower than outer. Inner gonostylus fleshy, covered with scarce setae.

Ovipositor. No female specimen was collected from Taiwan. Female specimens of this species from Korea with long, narrow cercus, smooth ventrally, rounded at tip. Cercus distinctly longer than hypogynial valvae ( Podenas & Byun, 2013).

Distribution. This species is known from Korea, Japan and Far East of Russia. It was found at altitudes from 1638 m to 2200 m in Taiwan (Fig. 16), but it is known from lower of altitudes of 200–800 m in Korea ( Podenas & Byun, 2013). Larvae of this species were observed in fast running mountainnous streams with sandy or rocky bottoms. Adults are flying or hiding in nearby vegetation. Adult flies of this species are attracted to light ( Podenas & Byun, 2013).

Material examined. TAIWAN: Kaohsiung: TaoYuan HsiNanShan Shin-Shan-Lin-Tao, 23.05N, 120.47E, C. Young, 22 Apr. 2005, 1 ♂; Taoyuan Twp Tengjhih Pk, Mid-altitude Res. Inst., 23.0853N, 120.7884E, 1638 m, C. Young, 4 April 2011, 1 ♂; Taichung: Pilushi, 2200 m, R. Davidson, C. Young, J. Rawlins, 22–23 May 1988, 1 ♂. Also compared with determined specimens from adjacent regions including Holotype and other type specimens, which are listed in Podenas & Byun (2013).

Remarks. Antocha gracillima was described by Alexander in 1924b based on single male specimen collected in Honshiu of Japan. Female specimen of this species was first described from Japan by Torii (1992). Specimens of Antocha gracillima from Taiwan exhibit different from type specimens and from study specimens from Korea and Japan. The most noticeable difference is that specimens from Taiwan have pale, indistinct wing stigma which is distinct dark in Korean and Japanese specimens. Some differences are also observed in male genitalia, especially tip of outer gonostylus, but in general, structure of male genitalia of Taiwanese specimens are very similar to that of Holotype ( Fig. 5 ). However, aedeagal complex of Taiwanese specimens is distinctly different from that shown in Torii (1992, Fig. 23, c), we suspect the illustration of Torii does not represent A. gracillima .

Figures

FIGURES 3 – 5. Antocha (Antocha) gracillima. 3. Ninth tergite of male, dorso-lateral aspect; 4. Gonocoxite with gonostyli, dorsal aspect; 5. Slide-mounted male genitalia of holotype, dorsal aspect. Abbreviations: gonap, gonapophyses; p, penis; tg 9, ninth tergite.