Hexatoma (Eriocera) ilwola Podenas, 2022

Podenas, Sigitas, Park, Sun-Jae, Byun, Hye-Woo & Podeniene, Virginija, 2022, Hexatoma crane flies (Diptera, Limoniidae) of Korea, ZooKeys 1105, pp. 165-208 : 165

Hexatoma (Eriocera) ilwola Podenas sp. nov.

Figs 12-19 , 60

Type material examined

(Fig. 60 ). Holotype, male (in ETOH), South Korea, Gyeongsangbuk-do, Yeongyang-gun, Ilwol-myeon, Yonghwa-ri, Mt. Ilwolsan, Yonghwasa Temple, 36°48.71'N, 129°07.55'E, alt. 510 m, 6 August 2001 (KU). Paratypes: North Korea, 1 female (pinned), Ompo, alt. 230 m, 28 August 1939, A. Yankovsky leg. (USNM); South Korea, 1 female (in ETOH), topotypic (KU); 2 females (in ETOH), Gyeongsangbuk-do, Yeongju-si, Punggi-eup, Samga-ri, Mt. Sobaeksan, 36°55.28'N, 128°30.33'E, alt. 400 m, 13 August 2001 (KU); 1 female (pinned), Gangwon-do, Chuncheon-si, Dongsan-myeon, Bongmyeong-ri, KNU experimental forest, 37°46.74'N, 127°48.94'E, alt. 230 m, 22 August 2014 (1), S. Podenas leg. (NIBR).

Diagnosis.

Large brownish gray species with body length 19.0-31.8 mm. Rostrum brown. Head and thorax with short and scarce pubescence. Male antenna reaching to approximately middle of abdomen if bent backwards. Prescutum and presutural scutum with four distinct dark brown stripes. Wing translucent with distinct stigma. Cell m1 present. Halter with dark knob. Femur yellow with narrowly blackened distal part. Abdominal sternites yellowish. Epandrium of male genitalia with wide V-shaped emargination. Gonostyli approximately equal in length. Posterior margin of inner gonostylus rounded, apical part slightly arched. Paramere V-shaped. Aedeagus simple, short, straight. Ovipositor with nearly straight cercus. Hypovalva long, distal part widened and setose, apex distinctly narrows into setiforme structure.

Etymology.

Species is named after type locality, Ilwol mountain.

Description.

Body coloration brownish gray. Body length of male 19.0 mm, female 23.0-31.8 mm, wing length of male 20.8 mm, female 16.3-20.6 mm.

Head (Fig. 13 ). Dark brown, dusted with gray, pale gray along eye margin, densely covered with short erect brown setae dorsally. Vertical tubercle large, rounded, with indistinct median vita, reddish brown fronto-laterally above base of antenna. Eyes widely separated in both sexes, distance between them at base of antennae equals to length of scape and pedicel taken together. Male antenna (Fig. 14 ) entirely brown, 7-segmented, 12.4 mm long, reaching to approximately middle of abdomen if bent backwards. Scape large, twice as long as wide, sparsely dusted with gray. Pedicel subglobular. Flagellomeres with two parallel lines of short spines medially. Basal flagellomere approximately as long as head and both basal antennomeres taken together, remaining flagellomeres getting longer towards apex of antenna. Female antenna (Fig. 15 ) 11-segmented, 4.8-6.5 mm long, reaching wing base if bent backwards. Scape elongate, cylindrical, 1.6 × longer than wide and 3 × as long as pedicel. Pedicel wider than long. Basal flagellomere 1.75 × as long as scape, remaining flagellomeres decreasing in length, apical segment elongate, approximately as long as preceding segment. Comparative length of flagellomeres slightly varies depending on specimen. Short spines that are present on male flagellum are completely missing on female antenna. Rostrum, palpus and mouth parts brown, just distal palpomeres somewhat darker.

Thorax. Cervical sclerites brown, dusted with gray. Pronotum much wider than long, gray with narrowly yellowish anterior margin. Prescutum light bluish gray, presutural scutum bluish gray laterally, brownish gray posteriorly. Prescutum and presutural scutum with four distinct dark brown stripes (Fig. 13 ) and covered with comparatively sparse medium long erect yellowish setae, that are less dense and shorter than in H. aequinigra , but denser and longer than in H. superba . Area separating medial stripes approximately as wide as stripe itself. Tubercular pits small, close to each other at anterior part of sclerite, pseudosutural fovea small, brownish. Postsutural scutum with each lobe dark brown with gray margins. Area between lobes brown. Scutellum dark brown, dusted with gray, posterior and lateral margins gray and covered with long yellow setae. Mediotergite gray because of dense pruinosity, dark brown posteriorly. Pleuron brown dorsally, whitish gray ventrally, covered with fine yellowish setae. Wing (Fig. 16 ) slightly iridescent, with brownish tinge, yellowish in costal area and at base. No other dark spots except elongate stigma. Veins light brown. Macrotrichiae on distal veins very scarce, nearly missing. Venation: humeral vein slightly before arculus, Sc very long, reaching wing margin distinctly beyond branching point of R2+3 and R4, sc-r close to the apex of Sc. Rs long and nearly straight, arched at base. Free end of R1 elongate, R2 twice its own length before apex of R1. R3 and R4 diverging, cell r3 with stem, which is nearly as long as m-cu. Cross-vein r-m distinct, transverse, slightly beyond base of discal cell. Discal cell 2 × longer than wide. Cross-vein m-cu at middle of discal cell length. Anal vein long, slightly concave in the middle, apex distinctly beyond the level of Rs base. Anal angle wide, posterior margin widely rounded. Stem of halter grayish brown with yellowish base, knob dark brown. Length of male halter 2.4 mm, that of female 1.9-2.3 mm. Coxae brownish yellow, densely covered with whitish-bluish gray pruinosity and long yellowish setae. Posterior coxa somewhat darker. Trochanters obscure yellow. Femur yellow with narrowly blackened distal part. Tibia brownish yellow with slightly darkened apex. Tibia of fore leg with single apical spur, tibiae of middle and hind pairs of legs with two apical spurs each. Basal tarsomere light brown with darker distal part, remainder of tarsus brown to dark brown. Male femur I: 9.5 mm long, II: 11.5 mm, III: 15.7 mm, tibia I: 14.0 mm, II: 9.5 mm, III: 17.0 mm, tarsus I: 16.2 mm, II: 12.7 mm, III: 12.0 mm. Female femur I: 9.0-10.5 mm long, II: 10.0-11.5 mm, III: 14.0-14.2 mm, tibia I: 11.0-12.2 mm, II: 10.0-10.4 mm, III: 13.0-13.5 mm, tarsus I: 11.0-12.0 mm, II: 8.5-10.2 mm, III: 7.8-8.5 mm long. Claw dark brown basally, reddish brown distally, simple, without spines.

Abdomen. Tergites dark brown, dusted with gray, narrowly orange along lateral margin, posterior margin narrowly orange starting from fourth tergite. All tergites with two pairs of transverse sutures and covered with very short yellowish setae. Sternites dark brown basally, obscure yellow laterally and posteriorly, dusted with gray. Male terminalia (Fig. 17 ) brownish yellow, slightly narrower than pregenital segments. Epandrium wider than long, posterior margin with wide V-shaped emargination. Gonocoxite elongate, slightly more than twice as long as wide at base, dorsal surface uniformly sclerotized. Two pairs of long narrow gonostyli. Outer gonostylus sclerotized, long, slightly arched, apex distinctly narrowed and spine-shaped. Inner gonostylus elongate, fleshy and setose, posterior margin rounded, apical part slightly arched. Paramere (Fig. 18 ) bifid, V-shaped, dorsal branch wider at base, tip folded, ventral branch straight and narrow. Aedeagus simple, short, and straight, protruding through aedeagal sheath in dorsal view, apex bifid. Anterior apodeme long and narrow, extending forward beyond frontal margin of aedeagal sheath. Female pregenital segment and ovipositor orange (Fig. 19 ). Tenth tergite elongate. Cercus slightly darker at base, nearly straight, rounded apex, distal part slightly raised upwards, very apex pale. Hypovalva long, parallel-sided at ~ 2/3 from base, distal part widened and setose, reaching to ~ 1/3 of cercus, apex distinctly narrows into setiforme structure.

Elevation range.

From slightly above 200 m to slightly above 500 m.

Period of activity.

Whole of August.

Habitat.

Sandy and rocky margins of medium-sized mountainous rivers covered with deciduous forest and scarce grassy vegetation (Fig. 20 ).

Distribution.

Korean Peninsula.

Remarks.

Hexatoma ilwola sp. nov. is most similar to H. aequinigra Alexander, 1934b, which is described and known only from the southern part of the Far East of Russia. Hexatoma aequinigra was described from the female, which is distinctly bigger than that of H. ilwola sp. nov. Hexatoma aequinigra has dense and long pubescence on head and thorax, while it is short and scarce in H. ilwola sp. nov. Hexatoma aequinigra has dark brown basal antennomeres, which are paler in H. ilwola sp. nov. Hexatoma aequinigra has pale yellow halter with dark brown knob, while the halter of H. ilwola sp. nov. is grayish brown with dark brown knob. Abdominal sternites of H. aequinigra are dark brown, but widely yellowish in H. ilwola sp. nov. Another similar species is H. sachalinensis , which is also known from the Far East of Russia, but it has a brownish black rostrum, dark brown femora, and brownish black tibiae. The rostrum of H. ilwola sp. nov. is brown, the legs yellow to brownish yellow. Unfortunately, the male of H. aequinigra is unknown and the male terminalia of H. sachalinensis have not been illustrated, thus comparison of the structure of male terminalia is not possible at the moment.

Figures

Figure 20. Habitat of Hexatoma (Eriocera) ilwola Podenas, sp. nov., KNU experimental forest.

Figures 12 - 19. Hexatoma (Eriocera) ilwola Podenas, sp. nov. 12 holotype, male, dorsal view 13 head and thorax, dorsal view, paratype, female 14 male antenna, holotype 15 female antenna, paratype 16 female wing, paratype 17 male genitalia, dorsal view, holotype 18 aedeagal complex, dorsal view 19 ovipositor, lateral view, paratype. Scale bars: 1.0 mm (12 - 17, 19); 0.1 mm (18).

Figures 59 - 66. Sampling localities of Korean Hexatoma (Eriocera) 59 H. (E.) gifuensis Alexander, 1933 60 H. (E.) ilwola sp. nov. 61 H. (E.) masakii Alexander, 1934 62 H. (E.) pernigrina Alexander, 1938 63 H. (E.) pianigra sp. nov. 64 H. (E.) serenensis sp. nov. 65 H. (E.) stackelbergi Alexander, 1933 66 H. (E.) ussuriensis Alexander, 1934.