Pachynotus arcuatus, Ren & Ren & Zhang, 2024

Ren, Jinliang, Ren, Li & Zhang, Runzhi, 2024, Revision of the Chinese Pachynotus Kollar & L. Redtenbacher, 1844 (Coleoptera, Curculionidae), with descriptions of two new species, ZooKeys 1197, pp. 153-169 : 153

Pachynotus arcuatus sp. nov.

Figs 3C, D , 4B, D, F , 6

Material examined.

Holotype, ♀: (white, printed): 西藏山南地区 [ Xīzàng Shānnándìqǖ] 羊措拉山 [ Yángcuòlāshān] / 28.09708°N, 91.933395°E / 4685 m / 2018.VIII.15 / 周润 [Zhōu Rùn] / 中科院动物所 [ Zhōngkēyuàn Dòngwùsuǒ]: IOZ(E)1965679.

Description.

Holotype, female. Measurements (in mm): standard length: 5.90; pronotal length: 1.90; pronotal width: 2.20; elytral length: 3.90; elytral width: 3.00; rostral length: 1.15; rostral width: 0.85.

Habitus and colour (Fig. 3C, D ): body elongate-oval, small; integument dark reddish brown; antennae and legs reddish brown, with light-grey scales; scales on dorsal and lateral surfaces of rostrum moderately dense, oval to elongate-oval; antennal scape and funicles without scales; pronotum with polygonal scales, moderately dense, not contiguous; scales on elytra polygonal, dense, not contiguous; scales on ventrites moderately dense, polygonal to elongate-oval; scales on legs dense; dorsal of tarsi surface without scales; body with erect to suberect and slightly longer setae, sparser; rostrum sparsely covered with suberect fine setae; antennal scape and desmomeres I-VII with long, fine and sparse setae; dorsal and lateral surfaces of pronotum with sparse, suberect setae; setae on interstriae long, erect to suberect, behind declivity slightly longer, erect, equal to 6 × diameter of one scale; setae on ventral surface moderately long, fine, erect.

Head (Fig. 4B ): moderately flat; dorsal surface smooth; punctures small and dense; eyes flat, oval; forehead weakly convex, moderately elevated than base of rostrum in lateral view.

Rostrum (Fig. 4B ): in dorsal view, 1.35 × as long as wide, apex narrower than base; sides narrowed from base to middle, and then slightly broadened to apex; dorsal surface with a broad, deep, median sulcus, reaching vertex of head; posterior angle of epistome 90°, smooth; mandibular scars oval; ventral margin of antennal scrobes visible at apical half in dorsal view; in lateral view, without triangular depression positioned laterally between eyes and antennal scrobes; prementum with two setae.

Antennae (Fig. 4F ): scape slender, clavate, reaching posterior margin of eyes at rest, 0.98 × length of funicle; desmomere I 1.43 × length of II, both segments elongate clavate; desmomere III short, clavate, 0.51 × length of II; desmomere IV 0.93 × length of III, nearly equal width; desmomeres IV-VI moniliform, equal in length and width; desmomere VII moniliform, 1.08 × length, 1.03 × width of VI; club elongate-oval, apically sharp, three-segmented, uniformly pubescent, segment I 1.21 × length of II; segment II shorter than segment III.

Pronotum: 0.86 × as long as wide; subquadrate in dorsal outline, strongly convex; sides strongly rounded, greatest width after midpoint, gradually narrowing towards both ends, fore margin shorter than posterior one; median sulcus fine, extremely shallow; postocular lobes absent, vibrissae fine, dense, yellow.

Scutellum: large and distinct, U-shaped, shiny, uncoated, reddish brown.

Elytra: 1.30 × as long as wide, moderately convex, elongate-oval; with base raised as prominent flange, not bisinuate; sides subparallel before declivity, only slightly narrowed near base; striae distinct, narrow, moderately deep, linear; puncture minute, spot-like, moderately dense, space between punctures narrower than diameter of punctures; interstriae wide, slightly flat, without tubercles, odd interstriae slightly raised than even ones.

Abdomen (Fig. 6A ): sternite I depressed in middle, slightly convex at sides; suture between sternites I and II slightly bisinuate; sternite II slightly convex; sternite I longer than II, sternite II slightly shorter than III and IV combined; sternites III and IV equal in length; sternite V moderately convex, apical round, longer than sternites III and IV combined.

Legs: rather short; femora clavate; fore tibiae obviously bent inward at apical third, apex neither projected inwards nor outwards (Fig. 4D ); inner margin of fore tibiae with several extremely small teeth; median- and hind tibiae without teeth; corbels of hind tibiae closed.

Genitalia: ventrite V (Fig. 6A ) parabolic, longer than ventrite II. Sternite VIII (Fig. 6C ) with spiculum ventrale thin, rod-like, and sinuate. Spermatheca (Fig. 6D ) with corpus subquadrate; cornu elongate, widely curved, wide U-shaped, apically gradually narrowed; ramus quadrate.

Male. Unknown.

Remarks.

This new species resembles P. pilosus sp. nov. but differs by the following characters: scutellum U-shaped; rostrum with a broad and deep median sulcus, reaching head vertex; elytra base raised as prominent flange; fore tibiae obviously bent inward at apical third.

Etymology.

Arcuatus, Latin participle, meaning “curved”, in reference to the fore tibiae, which is bent inward at its apical third.

Distribution.

China (Xizang).

Figures

Figure 3. Habitus of Pachynotus pilosus sp. nov. paratype A dorsal view B lateral view. Pachynotus arcuatus sp. nov. holotype C dorsal view D lateral view. Scale bars: 1 mm.

Figure 4. Pachynotus pilosus sp. nov. A head and rostrum, dorsal view C right protibia, anterior view E antenna, anterior view; Pachynotus arcuatus sp. nov. B head and rostrum, dorsal view D right protibia, anterior view F antenna, anterior view. Scale bars: 0.5 mm (A, B, E, F); 1 mm (C, D).

Figure 6. Abdominal and genital structures of Pachynotus arcuatus sp. nov. A ventrites, ventral view B sternite VIII and female genitalia, lateral view C sternum VIII, dorsal view D spermatheca, lateral view. Scale bars: 0.5 mm.