Dascillus jianyueae, Fang & Yan & Jin, 2020

Fang, Yan, Yan, Yijie & Jin, Zhenyu, 2020, Description of a new species of Dascillus Latreille from Henan, China (Coleoptera: Dascillidae), Zootaxa 4732 (2), pp. 341-345 : 341-344

Dascillus jianyueae sp. n. ( Figs 1–3 , 6–12, 15–16 , 19, 22–26 )

Etymology. The specific epithet is dedicated to Jianyue Qiu, co-collector of the type series.

Diagnosis. This species closely resembles D. cavaleriei Pic, 1930 and D. formosanus Jin, Ślipiński & Pang, 2013 in habitus and male aedeagus but differs by: (1) elytral setae denser on alternate intervals, forming longitudinal stripes ( Fig. 19 ) whereas elytral setae uniform and not forming any pattern in D. cavaleriei ( Fig. 20 ) and D. formosanus ( Fig. 21 ); (2) abdominal ventrites with glabrous spots on each side ( Figs 8–9 ); (3) anterior edge of pronotum bisinuate ( Fig. 3 ), not broadly rounded ( Figs 4–5 ); (4) posterior edge of male tergite IX not straight or obtuse ( Fig. 18 ) as in D. cavaleriei but obviously emarginate ( Fig. 16 ); (5) dorsal lobe of aedeagus obtuse ( Figs 10–11 ) at apex, not acute or emarginate ( Fig. 13 ) as in D. cavaleriei ; (6) phallobase not sinuate ( Fig. 14 ) basally as in D. formosanus but almost forming a straight line ( Fig. 10 ).

Description. Male ( Fig. 2 ). Length 11.4–11.7 mm, width 4.6–4.8 mm. Body 2.4–2.5× longer than broad. Head, antennae, pronotum, scutellar shield and venter black, elytra and legs dark brown. Upper surfaces densely clothed with short and adpressed setae. Setae on head, pronotum and elytra uniformly yellowish-brown; elytral setae denser on alternate intervals and forming slightly lighter longitudinal stripes; venter covered by brown dense pubescence.

Head. Antennae short, reaching posterior margin of pronotum. Antennomere 3 about 3.2–3.3× as long as broad, 1.1–1.2× as long as antennomere 4; terminal antennomere distinctly longer than penultimate. Mandible strongly curved apically; incisor edge with two teeth. Apical palpomere of both maxilla and labium weakly expanded.

Pronotum trapezoidal, 0.5–0.6× as long as wide, widest just before base; anterior edge emarginate; sides sinuate. Lateral carina narrowly explanate with marginal bead, edge smooth with distinct fringe of setae; anterior angles broadly rounded. Disc strongly convex, punctation coarse and dense.

Pterothorax. Scutellar shield 0.6–0.7× as long as wide, obtuse anteriorly, acute posteriorly. Elytra moderately convex, together 2.0–2.1× as long as wide, 4.7–4.8× as long as pronotum.

Abdominal ventrites ( Figs 6, 8 ) with glabrous spots on each side; ventrite 5 broadly rounded apically, 0.3–0.4× as long as wide, 1.1–1.2× as long as ventrite 4. Sternite IX ( Fig. 15 ) apically truncated, at base obtuse, bearing uniformly short setae in middle and apical part. Posterior edge of tergite IX ( Fig. 16 ) emarginate. Tergite X slightly shorter than tergite IX, apically obtuse.

Aedeagus ( Figs 10–12 ). Phallobase at base straight. Parameres about as long as phallobase, inner margin upturned apically, slender and narrowly rounded at apex. Ventral lobe obtuse at apex; dorsal lobe broadly rounded but not compressed at apex.

Female ( Fig. 1 ). Externally identical to male. Length 12.0– 12.9 mm, width 6.0– 6.3 mm. Female spiculum ventrale slightly emarginate apically ( Fig. 23 ), genitalia weakly sclerotised with vagina and bursa copulatrix not clearly separated; bursa copulatrix without sclerites; spermatheca small and not sclerotised. Ovipositor ( Fig. 22 ) short; paraprocts entirely sclerotised, without baculi, about as long as gonocoxites; proctiger absent; gonocoxites entirely sclerotised ventral of paraprocts, triangular and strongly bent, apices prominent, densely setose dorsally, without baculi; gonostyli absent.

Type material. Holotype (1 ♂): Henan, Neixiang County, Baotianman National Nature Reserve , 33°29ʹ31.03ʹʹN, 11 1°56ʹ24.88ʹʹE, 21-vi-2017, Hao Xu, Jianyue Qiu (YZU).

Paratypes (2 ♂, 14 ♀♀): same data as holotype .

Natural history. Like D. levigatus Li et al., 2017 , adults of D. jianyueae sp. n. were observed feeding on pollen of Castanea sp. ( Fagales : Fagaceae ) in Baotianman National Nature Reserve ( Figs 24–25 ).

Distribution. The species is so far known only from the type locality in Henan, China ( Fig. 26 ).

Remarks. The new species is distributed in the north of Qinling Mountains which extend 500 km from west to east and 140–200 km from north to south. They provide a natural boundary between the Yangtze River and the Yellow River, the two major river systems in China, and are generally accepted as the boundary between the Palaearctic and Oriental Regions. The presumably closely related species mentioned in the diagnosis, i.e. D. formosanus found only in Taiwan and D. cavaleriei known from two localities in Hubei and Guizhou Provinces, occur ca. 600 km apart but both south of the Qinling Mountains.

Figures

FIGURE 26. Distribution of Dascillus jianyueae sp. n. (red circle), D. cavaleriei (yellow triangles) and D. formosanus (blue squares).

FIGURES 1–2. Habitus of Dascillus jianyueae sp. n.: (1) female; (2) male.

FIGURES 3–5. Pronotum, dorsal view: (3) Dascillus jianyueae sp. n.; (4) D. cavaleriei; (5) D. formosanus.

FIGURES 6–9. Dascillus jianyueae sp. n. abdomen: (6) female, ventral; (7) male, ventral; (8) female, lateral; (9) male, lateral.

FIGURES 10–18. (10–14) aedeagus: (10–12) Dascillus jianyueae sp. n.: (10) ventral, (11) dorsal, (12) lateral; (13) D. cavaleriei, ventral; (14) D. formosanus, ventral; (15, 17) male abdominal sternite IX: (15) D. jianyueae sp. n., (17) D. cavaleriei; (16, 18) male abdominal tergites IX–X: (16) D. jianyueae sp. n., (18) D. cavaleriei.

FIGURES 19–23. (19, 22–23) Dascillus jianyueae sp. n.: (19) elytron, dorsal, (22) ovipositor, (23) female spiculum ventrale; (20) D. cavaleriei, elytron, dorsal; (21) D. formosanus, elytron, dorsal.

FIGURES 24–25. Habitats of Dascillus jianyueae sp. n. in Baotianman National Nature Reserve (Henan, China), by Jianyue Qiu.