Antocha (Antocha) styx Alexander, 1930

Podenas, Sigitas & Young, Chen W., 2015, Antocha crane flies from Taiwan (Diptera: Limoniidae: Limoniinae), Zootaxa 4048 (4), pp. 523-537 : 530-532

Antocha (Antocha) styx Alexander, 1930

( Figs. 7–13 )

Antocha (Antocha) styx Alexander, 1930:517 .

Diagnosis. This is a medium-sized crane fly. Ground color of body black, body covered with gray pruinosity, dense on thoracic pleuron, thus general body color ranging from dark gray to blackish gray. Wings with blackish tinge. Wing stigma indistinct, slightly darker than wing membrane. Posterior margin of ninth tergite of male genitalia slightly concave, gonocoxite oval, without additional lobes, outer gonostylus arched distally with acute tip and small outgrove on inner margin. Aedeagus with large shield, paramere long, narrow, rod-like. Cercus of ovipositor with small angle on ventral margin and microscopic hook at apex.

Description. Based on dry-mounted specimens of both sexes. Body length: Males 3.70–5.65 mm; females 4.9–7.1 mm. Wing length: Males 4.75–7.00 mm; females 5.7–8.0 mm.

Head. Head black dorsally, covered with grayish pruinosity, denser along orbits. Antenna black throughout, 16–segmented, 0.70–1.05 mm in males, 0.85–1.25 mm in females. Scape nearly cylindrical. Pedicel brownish gray, wider distally, narrower basally. Flagellomeres oval, decreasing in size towards apex, apical segment about onethird longer than penultimate. Verticils short, distinctly shorter than respective segments, slightly longer than whitish pubescence covering flagellomeres. Rostrum black, covered with scarce grayish pruinosity. Palpus black, covered with scarse, short, erect whitish setae.

Thorax. Thorax dark brown to blackish brown dorsally, bluish gray laterally and ventrally. Antepronotum black, covered with dense brownish gray pruinosity. Pronotum gray laterally. Mesonotal prescutum dark brown, lighter laterally with three confluent blackish brown stripes, which cover nearly entire surface of sclerite. Pseudosutural fovea surrounded by gray. Median stripe separated from lateral stripes by rows of short erect brown setae. Mesonotal scutum blackish brown, covered by dense gray pruinosity. Scutellum uniformly dark brown, covered by dense gray pruinosity. Mediotergite blackish brown, with indistinct brownish spots on both sides, covered with dense gray pruinosity. Pleuron generally bluish gray, katepisternum brownish gray. Wing with blackish tinge. Stigma indistinct, nearly invisible. Wing veins blackish brown. Venation typical for subgenus ( Fig. 7 ): discal cell closed, short and wide; Rs very long and straight, basal deflection of CuA1 distinctly before branching point of M, anal angle big and nearly right-angled. Stem of haltere brown, somewhat lighter at base. Knob blackish. Haltere 0.65–0.90 mm long in males and 0.8–1.0 mm in females. Coxae dark brown basally, turning light brown distally. Trochanters brown at base, turning blackish distally. Legs uniformly brown, just distal tarsomeres turning black. Male femur I: 3.70–5.75 mm long, II: 4.15–6.25 mm, III: 4.25–6.60 mm; tibiae I: 4.0– 6.4 mm, II: 3.85–5.60 mm, III: 4.30–6.75 mm; tarsus I: 4.1–6.2 mm, II: 3.50–4.95 mm, III: 3.80–5.35 mm long. Female femur I: 4.1–5.3 mm long, II: 4.3–5.7 mm, III: 4.9–6.0 mm; tibiae I: 4.7–6.1 mm, II: 4.1–5.7 mm, III: 4.8–5.9 mm; tarsus I: 4.2–5.6 mm, II: 3.55–4.70 mm, III: 3.8–4.7 mm long. Claw of male with a single, slender subbasal spine.

Abdomen. Abdominal tergites semi-polished, black, covered with brownish gray pruinosity, the caudal margins narrowly brownish gray. Tergites covered with short, indistinct setae. Basal and distal sternites black, sternites 2–6 brown with blackened lateral and posterior margins. Posterior margins of all sternites narrowly rimmed by gray. Abdomen ventrally covered by dense gray pruinosity and distinct long yellowish erect setae.

Hypopygium. Male genitalia ( Fig. 8 ) generally black, central part of ninth tergite and inner parts of gonocoxites brownish. Gonostyli ( Fig. 9 ) distinctly reddish brown. Ninth tergite with slightly concave posterior margin. Gonocoxite elongate, oval, without extra lobes. Outer gonostylus arched, with acute tip and small emargination on inner margin. Inner gonostylus fleshy, distinctly arched, covered with scarce setae. Penis long and narrow, covered by wide sheath ( Fig. 10 ). Gonapophysis narrow, rod-like, distinctly shorter than penis ( Fig. 11 ).

Ovipositor ( Fig. 13 ) with tenth tergite dark brown. Cercus reddish brown with dark brown base, distal part slightly bent upwards, tip with small subapical angle on ventral margin and microsopic hook at apex ( Fig.12 ). Hypovalvae brownish yellow, tip acute, reaching to basal part of cercus.

Distribution. This species is endemic to Taiwan (Fig. 18). It was found at altitudes from 760 m through 2200 m. All type specimens were collected at the end of October, more recent specimens were found from second part of March through end of May. It seems, that species has at least two generations a year.

Material examined. TAIWAN: Paratypes: Hassensan, 3,500 feet, S. Issiki, 24 October 1929, 1 ♂ (body pinned, right wing, leg, fragment of antenna and male terminalia slide-mounted), 1 ♂ (pinned); Meizi Hot Spring, 2,500 feet, S. Issiki, 25 October 1929, 1 ♂ (body pinned, right wing, leg, antenna and male terminalia slidemounted), 4 ♂ (pinned); specimens identified by S. Podenas: Taichung, Bi-Lu-Si Taiwan Forest Res. Inst., 1637 m, 24.2226N, 121.3050E, Chen Young, 22 March 2011, 4 ♂, 6 ♀; Taichung, Pilushi, 2200 m, R. Davidson, C. Young, J. Rawlins, 22–23 May 1988, 7 ♂, 6 ♀.

Previous records for Taiwan: Holotype: Meizi Hot Springs, foot of Hassensan, 2,500 feet, S. Issiki, 26 October 1929, 1 ♂; Paratopotypes: Meizi Hot Springs, foot of Hassensan, 2,500 feet, S. Issiki, 25 October 1929, 3 ♂; Paratypes: Hassensan, 3,500 feet, S. Issiki, 24 October 1929, 2 ♂ ( Alexander, 1930).

Remarks. Antocha styx was described by Alexander in 1930 based on male specimens collected by S. Issiki in October around Meizi Hot Springs, foot of Hassensan of Taiwan. This species is known only from Taiwan and judging from numbers of collected specimens it could be the most common species of Antocha on the island.

Figures

FIGURES 7 – 13. Antocha (Antocha) styx. 7. Wing; 8. Male genitalia, dorsal aspect; 9. Gonostyli, dorsal aspect; 10. Aedeagal complex covered by ninth sternite, ventral aspect; 11. Aedeagal complex, ventral aspect; 12. Tip of cercus, lateral aspect; 13. Ovipositor, lateral aspect. Abbreviations: arc, arculus; cerc, cercus; d, discal cell; h, humerus; hyp vlv, hypogynial valve; st, sternite; tg, tergite.