Protohelius japonicus Kato

Kato, Daichi, 2022, Four genera of Limoniidae (Diptera) new to Japan with descriptions of new species, Zootaxa 5168 (4), pp. 401-418 : 414-416

Protohelius japonicus Kato , sp. nov.

( Figs 8A–E, G–H , 9 , 10D )

Diagnosis. Ocherous to brownish species with unpatterned wing except stigma ( Fig. 8A ). Vertex at narrowest point 1.5 times as wide as scape. Presutural area of mesonotum with three dark stripes. Scutal lobe and mediotergite mainly dark brown. Legs generally yellowish. Cell m 1+2 2–3 times as long as cell dm. Abdomen weakly dark toward distal segment, yellowish on basal sternites. Lobe of gonostylus with outer lobe not distinctly wide on distal part, inner lobe 3/5 length of outer one.

Type material. HOLOTYPE male, JAPAN, Nansei Islands , Ishigaki Is., Ishigaki-shi , Hirae, trailhead of Mt. Omoto-dake, alt. 180 m, N24.4177, E124.1886, 27.IX.2013, D. Kato ( BLKU) . PARATYPES: JAPAN: [Nansei Islands] Ishigaki Is.: 1 female, Tonoshiro , Omoto-Minanushinokami , alt. 100 m, N24.4127, E124.1766, 26.IX.2013, D. Kato ( BLKU); 1 female, same data as holotype; 2 males 2 females, Miyara, Mt. Omoto-dake, alt. 110 m, N24.4382, E124.2097, 26.IX.2013, D. Kato ( BLKU); 2 males 1 female, same data as previous except 27.IX.2013; Iriomote Is.: 1 male, Haeminaka, alt. 170–220 m, N24.2988, E123.8644, 19. V.2016, D. Kato ( BLKU) .

Description. Male.

Head. Pale ocherous to grayish ocherous, covered with yellow and dark brown setae; posterior part sometimes more yellowish. Vertex at narrowest point 1.5 times as wide as scape. Antenna dark brown, about three times as long as head; basal two segment ocherous. Scape cylindrical, about twice as long as wide. Pedicel globular, about as long as wide, about as wide as scape and half length of scape. Flagellum 14-segmented. Flagellomere cylindrical, slightly and gradually narrowed toward apical segment; flagellomere 1 about three times as long as wide; apical segment distinctly short and roundish, about 1/5 to 1/3 length of penultimate one. Verticils on flagellomeres almost same length in whole segments, at most as long as each segment except apical one. Flagellomeres 1 to 13 covered with whitish pubescences, about 1/4 to 1/2 length of verticil. Rostrum short, about 2/3 length of scape. Palpus 5- segmented, brown to dark brown; palpomere 2 widest; palpomeres 4 and 5 longest. Labellum dark brown.

Thorax. Sparsely covered with short yellow setae. Pronotum dark brown, yellowish on postpronotum. Presutural area of mesonotum yellowish ocherous to dark ocherous, more brownish medially, bearing three darker stripes; median stripe almost same width in whole length, extending from anterior end of mesonotum and ending slightly before transverse suture, sometimes split by capillary paler line on posterior part; lateral stripe about half length and width of middle stripe, situated posterior to level of prescutal pit and reaching at transverse suture. Scutal lobe dark brown, lateral margin and interspace between scutal lobes pale ocherous to ocherous. Scutellum pale ocherous to grayish ocherous. Mediotergite dark brown, yellowish at anterior corner. Pleuron yellow to ocherous; dorsal part sometimes indistinctly darker. Dorsopleural membrane yellow. Prescutal and tuberculate pits absent. Wing ( Fig. 8B ) tinged with brown, stigma weakly dark, short oval. Sc ending between level of fork of Rs to crossvein r-m. Crossvein Sc-r situated 4–6 times length of itself proximal to tip of Sc. Cell dm 2–2.5 times as long as wide. Cell m 1+2 2–3 times as long as cell dm. Crossvein m-cu situated at basal 1/8–1/3 of cell dm. Legs pale yellow to yellowish ocherous, covered with yellow setae on coxae and trochanters and mainly with brown setae on succeeding segments. Base of fore coxa and distal segments of tarsi darkened. Claw half length of tarsomere 5, strongly curved, with small tooth at base. Halter dark brown; stem passing into yellowish ocherous to base.

Abdomen. Brown, weakly darker toward distal segment; basal sternites yellowish. Tergites each often weakly and narrowly dark at lateral and caudal margins. Male terminalia ( Fig. 8C ) brown, ocherous on gonocoxite. Tergite 9 weakly concaved medially. Sternite 9 ( Fig. 8D ) produced posteriorly, interrupted at middle of caudal margin by deep V-shaped notch. Gonocoxite simple, slightly longer than tergite 9. Clasper of gonostylus ( Fig. 8E ) roughly sickle-shaped, wide on basal half, curved near middle; distal half narrow rod-shaped, obtuse at tip; inner margin near base of narrow distal part with triangular lobe. Lobe of gonostylus slightly longer than outer gonostylus, forked near middle; outer lobe longer and curved near base, rounded and not distinctly wide at tip; inner one 3/5 length of outer lobe. Interbase ( Figs 8G–H ) fused medially to form long and arched bridge. Lateral process of aedeagal sheath narrow distally, long triangular in lateral view; basal parts fused medially to form bridge ventral to aedeagus. Aedeagus short, rod-shaped, ending far before tip of lateral process of aedeagal sheath.

Female.

Generally resembling male. Claw shorter, 1/3 length of tarsomere 5, without small tooth at base.

Female terminalia ( Figs 9 A–B ). Yellow to ocherous, with longitudinal dark stripe on tergite 10. Tergite 8 strongly concaved at middle of posterior margin. Tergite 9 about half width of tergite 8 in lateral view, with very large U-shaped notch at middle of posterior margin. Tergite 10 about 2.3 times as long as wide, narrow on basal 1/3 and distal 1/5. Cercus amber color, slightly shorter than tergite 10, weakly upcurved toward tip. Sternite 8 ( Fig. 9C ) squarish, slightly longer than wide. Hypogynial valve amber color, about twice as long as sternite 8, about twice wider than cercus in lateral view; tip ending near level of middle of cercus. Sternite 9 ( Fig. 9D ) with anterior part flat rod-shaped, rounded at tip; lateral side with curved arm directed posteriorly, widened on distal part, rounded at tip; posterior part Y-shaped, broader posteriorly on posterior stalk part, truncated at posterior end. Sternite 10 ( Fig. 9E ) roughly V-shaped, wide on middle of each side, arched on outer lateral margin.

Measurements. Male (n = 6): body length 5.3–6.8 mm, wing length 6.2–7.7 mm. Female (n = 5): body length 8.1–8.6 mm, wing length 7.3–7.8 mm.

Etymology. This species is named after Japan. The specific name is a neuter adjective in nominative singular.

Distribution. Japan (Nansei Islands).

Remarks. This species is similar to a Chinese species, P. tinkhami Alexander, 1938 , but is differentiated from it by the following character: anterior vertex narrower than twice width of scape (wider than twice width of scape in P. tinkhami ); presutural area of mesonotum and scutal lobes marked with dark brown (unmarked in P. tinkhami ); lobe of gonostylus with inner lobe 3/5 length of outer one ( Fig. 8E ) (half length of outer lobe in P. tinkhami ( Fig. 8F )).

Figures

FIGURE 8. Protohelius japonicus sp. nov. (A–E, G–H) and P. tinkhami Alexander, 1938 (F, traced from the holotype slide): A, habitus (male); B, wing; C, male terminalia, dorsal view; D, sternite 9, ventral view; E, outer and inner gonostyli, outer surface; F, lobe of gonostylus; G, aedeagal complex, dorsal view; H, ibid, lateral view (left = dorsal). Scale bars: A–B, 2 mm; C–H, 0.1 mm (not given in F).

FIGURE 9. Female terminalia of Protohelius japonicus sp. nov.: A, overall, lateral view; B, ibid, dorsal view; C, sternite 8 and hypogynial valve, ventral view; D, sternite 9, ventral view (left = anterior); E, sternite 10, ventral view (left = anterior). Scale bars: A–C, 0.3 mm; D–E, 0.1 mm.

FIGURE 10. Distributions of species. A, Crypteria nippon sp. nov.; B, Dasymallomyia ditenostyla Alexander, 1964 (red), and D. tachii sp. nov. (orange); C, Eupilaria japonica sp. nov.; D, Protohelius japonicus sp. nov.