Helius (Helius) nipponensis ( Alexander, 1913 )

Podenas, Sigitas, Byun, Hye-Woo & Kim, Sam-Kyu, 2015, Limoniinae crane flies (Diptera: Limoniidae) new to Korea, Journal of Species Research 4 (2), pp. 61-96 : 78-80

Helius (Helius) nipponensis ( Alexander, 1913)

Rhampidia nipponensis Alexander, 1913: 207 ; 1920b: 8. Helius nipponensis Alexander, 1929: 532 .

General coloration light brown. Body length of male 4.9 to 8.0 mm, female 5.9­7.8 mm. Wing length of male 5.6 to 8.1 mm, female 6.2­8.3 mm.

Head dark brown, covered with sparse grayish pruinosity. Anterior vertex very narrow, covered with sparse erect grayish setae. Eyes large, ventrally nearly reaching each other. Length of male antennae 1.08­2.50 mm, that of female 1.55­1.80 mm. Antenna brown. Scape slightly widened distally, dark brown, covered with sparse gray pruinosity. Pedicel oval, yellowish brown in some specimens, dark brown in other. Flagellum 14­segmented, dark brown at base, getting somewhat lighter distally. Just base of basal flagellomere yellowish. Flagellomeres long, cylindrical. Basal flagellomere slightly less than twice as long as pedicel, widened in middle. Succeeding few flagellomeres subequal in length, cylindrical. Apical flagellomere very small, distinctly shorter than penultimate in male, but just slightly shorter in female. Verticils nearly twice as short as length of respective segments. Erect brownish pubescence, covering segments is rather short, uniformly dense on all sides of flagellum. Rostrum blackish, covered with short semi­erect blackish setae, 0.55­0.85 mm long in male and 0.55­1.00 mm long in female. Palpus dark brown, covered with erect dark brown setae. Mouth parts light yellow, covered with dark brown erect setae.

Thorax generally pale brownish yellow. Pronotum dark brown dorsally, yellow laterally. Mesonotal prescutum light brown, getting brownish yellow laterally. Median prescutal stripe is longest and broadest, dark brown, especially dark frontally. Lateral stripes less distinct; they start behind the pseudosutural fovea and extend onto scutal lobes, which are dark brown. In dry specimens, that were collected long time ago, lateral stripes could be missing. Scutellum brownish yellow, margins yellow, frontal part brown. Mediotergite brownish yellow or light brown. Pleura brownish yellow, in some specimens getting whitish yellow posteriorly. Ventral surface of katepisternum brown. In general, thorax of Korean specimens is somewhat lighter than that of Japanese specimens, described by Alexander (1913; 1920b). Wing ( Fig. 6B ) translucent, yellowish, without dark spots, except very weak darkening in stigmal area. Stigma big but very indistinct, light brown. Costal area more intensely yellowish, than remainder of wing. Veins brownish. Venation: Sc 1 reaching wing margin at or slightly before branching point of Rs, Sc 2 close to Sc 1 tip. Rs slightly arched at base. Separate vein R 2 missing. Both branches of Rs distinctly diverging distally. Cross­vein r­m very short, in some specimens it is shorter, than that shown in Fig. 6B , but in this case proximal part of discal cell is wider. Discal cell wide, about 1.6 times as long as wide, sometimes less than that. Basal deflection of CuA 1 distinctly beyond branching point of M, about at one­fifth of discal cell’s length. Both anal veins long and nearly straight. Anal angle medium­sized, comparatively narrow. Length of male halter 0.80­1.25 mm, that of female 0.85­1.10 mm. Stem of halter light yellow, base whitish, knob slightly darkened, brownish. Frontal coxa brownish yellow, middle coxa yellow, posterior coxa whitish yellow. Trochanters yellow, distal margin blackened. Femur yellowish brown, lighter basally. Tibiae brown. Tarsi brown passing into dark brown distally. Male femur I: 4.8­5.8 mm long, II: 5.1­7.6 mm, III: 5.1­7.4 mm; tibiae I: 6.7 mm, II: 5.5­8.2 mm, III: 8.0 mm; tarsus I: 5.4­5.8 mm, II: 4.9­6.2 mm, III: 5.8 mm long. Female femur I: 5.1­6.4 mm long, II: 5.1­6.5 mm, III: 5.3­5.6 mm; tibiae I: 6.5­6.8 mm, II: 6.1­7.0 mm, III: 5.9­6.0 mm; tarsus I: 5.1­5.8 mm, II: 5.4 mm, III: 4.1­5.0 mm long. Claw simple, yellowish brown, without additional spines.

Abdominal tergites dark brown, with or without weak median dark line. Sternites somewhat lighter than tergites, especially at base of abdomen. Distal segments distinctly blackened in male, less so in female. Tergites and sternites covered with semi­erect scarce, yellowish setae. Membranes between tergites and sternites yellow, better visible in females. Abdomen of females in ethanol could be distinctly lighter, fouly yellow, with more distinct longitudinal dorsal line. Male genitalia ( Fig. 6E ) brownish yellow. Ninth tergite simple, posterior margin with small median emargination, margins of which covered with short blackish setae. Gonocoxite elongate, wider basally than distally. Outer gonostylus short, slightly widened distally, produced into slightly arched apical spine, bearing small subapical spine and three long setae on posterior margin. Inner gonostylus distinctly longer than outer, fleshy, wider basally, turning narrower distally, tip blunt and narrow. Gonostylus covered with semi­erect setae. Penis short, simple and narrow. Interbase narrow, acute, spine­shaped. Ovipositor ( Fig. 6F ) yellow. Cercus brownish dorsally, strongly arched, with apex turned up­wards. Hypovalvae long, not reaching tip of cercus.

Elevation range in Korea. Specimens are known to occur at altitudes from 0 m to 630 m.

Period of activity. Adults are flying from late June through October in South Korea.

Habitats. The species was collected in dense willow shrubs with grassy vegetation on wet, swampy soil; on river slopes, covered with deciduous forest; in high grassy vegetation on banks of slow flowing water pond; in abandoned farm land with small stream at mixed forest edge. Males were attracted to light. Larvae were developing at margins of ponds and marshes, in mud rich of decaying plant material.

General distribution. The species is known from Japan, Honshu Island and China, Zhejiang.

Examined materials ( Fig. 10H ): 1♂ (pinned), S. Korea, #14, Oho­ri, east coast, 128°30 ʹ, 38°20 ʹ, 10­50 ʹ, 1954.07.11, coll. George W. Byers ( KU); 2♂♂ (pinned), Korea, Davis Trap 16, 1959.08 ( USNM); 1♂ (pinned), Korea, Pusan, Davis Trap 23, 1959.10 ( USNM); 1$ (in ethanol), S. Korea, Gangwon­do , Wondeok­eup , Wolcheon­ri , Samcheog , N37.14899, E129.35933, alt. 629 m, 2012.06.23, coll. S. Podenas ( NIBR); 1♂ (pinned), 1♂ (in ethanol), S. Korea, Jeollanam­do, Gurye­gun , Toji­myeon , Jirisan National Park , Piagol valley , N35. 26590, E127.58096, alt. 446 m, 2014.08.24, coll. S. Podenas, with net and at light ( NIBR); 5♂♂, 4$$ (in ethanol), S. Korea, Jeollabuk­do, Buan­gun , Byeosan­myeon , Daehang­ri , Byeonsanbando National Park , Jiksocheon , N35.67249, E126.56445, alt. 26 m, 2014.08.26, coll. S. Podenas ( NIBR); 3♂♂, 2$$(in ethanol), Gyeongsangnam­do, Changwon­si, Masanhappo­gu, Jindong­myeon, Dagu­ri, N35.113086, E128.530671, 2014.08.31, coll. S. Podenas ( NIBR). Also compared with: Holotype, 1$ (slide­mounted), Japan, Tokyo, April 26, 1912; Metatype: 1♂ (slide­mounted), China, Hang­chow, Che­kiang, April 28, 1924, coll. S. Manson, det. Ch. Alexander ( USNM).

Discussion. Helius nipponensis is closely related to H. nawaianus Alexander, 1929 ( Fig. 6 A­C), but differences could be observed in wing venation, and especially in outer gonostylus. Outer gonostylus of H. nipponensis is produced into a long apical spine ( Fig. 6E ), while it ends in two subequal blackened knobs or obtuse spines in H. nawaianus ( Fig. 6C ). H. nawaianus is known only from islands (Kunashir, Sakhalin and Honshu). Other closely related species is H. brevioricornis ( Alexander, 1920b) , known only from Japan. Male genitalia of H. nipponensis and H. brevioricornis are very similar (compared with slide­mouted genitalia of Alexander’s metatype). According to Alexander (1920b), H. nipponensis has longer male antennae. The clear difference between these two species is coloration of thorax, which is brownish yellow in H. nipponensis and gray in H. brevioricornis . It is possible that they represent just different morphs of same species, but additional studies are needed.

Figures

Fig. 6. Helius. A­C. H. nawaianus. A. wing, B. basal flagellomeres. C. outer gonostylus of male genitalia. D­F. H. nipponensis. D. wing. E. male genitalia, dorsal view. F. ovipositor, lateral view.

Fig. 10. Distribution maps.A. Achyrolimonia basispina. B. Discobola annulata. C. Discobola margarita. D. Elephantomyia (Elephantomyia) edwardsi. E. Geranomyia gifuensis. F. Geranomyia multipuncta. G. Geranomyia neavocetta. H. Helius (Helius) nipponensis. I. Libnotes(Afrolimonia) ladogensis. J. Libnotes (Libnotes) amatrix. K. Libnotes (Libnotes) basistrigata. L. Libnotes (Libnotes) longistigma. M. Libnotes (Libnotes) nohirai. N. Libnotes (Libnotes) puella. O. Trentepohlia(Mongoma) pennipes. P. Trentepohlia (Trentepohlia) septemtrionalis.