Xyleborus yunnanensis, Smith & Beaver & Cognato, 2020

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China, ZooKeys 983, pp. 1-442 : 1

Xyleborus yunnanensis sp. nov. Fig. 91G, H, L

Type material.

Holotype, female, China: S-Yunnan, Xishuangbanna, 28 km NW Jinghong, vic. An Ma Xi Chan (NNNR), 22°12'N, 100°38'E, 700 m, forest, EKL, 05.iv.2009, L. Meng (NKME). Paratypes, female, as holotype (RABC, 1); as holotype except: 28.vi.2008, A. Weigel (MSUC, 1).

Diagnosis.

2.7-2.75 mm long (mean = 2.73 mm; n = 3); 3.06-3.17 × as long as wide. This species is distinguished by the declivital interstriae 1 widened from base to midpoint of declivity, then narrowed to apex; declivital striae not impressed; three strong spines on declivital interstriae 1, and three slightly weaker spines on declivital interstriae 3, declivital interstriae 2 with at most a small spine near top of declivity; all interstriae with spines only, lacking granules; discal interstriae much wider than striae, strial punctures approximately 2 × diameter of interstrial punctures, the latter very sparse on disc; declivital posterolateral margin costate and with a row of small spines to interstriae 6; integument smooth and strongly shiny on both dorsal and ventral surfaces, only the head reticulate and less shiny.

Similar species.

Xyleborus mysticulus , X. pfeilii .

Description

(female). 2.7-2.75 mm long (mean = 2.73 mm; n = 3); 3.06-3.17 × as long as wide. Body red-brown. Legs and antennae light brown. Head: epistoma entire, transverse, with a row of hair-like setae. Frons weakly convex to upper level of eyes; median carina absent; surface shagreened, alutaceous, punctate; punctures sparse, shallow, setose, each bearing a long, erect hair-like seta. Eyes shallowly emarginate just above antennal insertion, upper part smaller than lower part. Submentum triangular, deeply impressed. Antennal scape regularly thick, slightly longer than club. Pedicel as wide as scape, as long as funicle. Funicle 4-segmented, segment 1 shorter than pedicel. Club longer than broad, obliquely truncate, type 2; segment 1 corneous, transverse on anterior face, occupying basal 2/5, nearly covering posterior face; segment 2 narrow, corneous; segment 1 present on posterior face. Pronotum: 1.33 × as long as wide. In dorsal view long and rounded frontally, type 7, sides parallel in basal 3/4, rounded anteriorly; anterior margin without serrations. In lateral view elongate, disc longer than anterior slope, type 7, summit on anterior 1/3. Anterior slope with densely spaced, moderately large asperities, becoming lower and more strongly transverse towards summit. Disc shiny with sparse, fine punctures bearing long, fine, erect hair-like setae, some longer hair-like setae at margins. Lateral margins obliquely costate. Base transverse, posterior angles broadly rounded. Elytra: 1.79 × as long as wide, 1.34 × as long as pronotum. Scutellum moderately sized, linguiform, flush with elytra, flat, shiny. Elytral base transverse, edge oblique, humeral angles rounded, parallel-sided in basal 3/4, then broadly rounded to apex. Disc shiny, striae not impressed, with small, shallow punctures separated by three diameters of a puncture, glabrous; interstriae flat, very sparsely finely punctate, punctures 1/2 size of strial punctures, each with a short, thick, erect seta. Declivity strongly convex, steep, shiny; striae not impressed, strial punctures larger, coarser than on disc; interstriae 1 widened from base to declivital midpoint, then narrowed to apex; interstriae 1 with three strong spines, interstriae 2 with at most a small spine near declivital summit, interstriae 3 with three slightly weaker spines than those of interstriae 1. Posterolateral margin costate, granulate to interstriae 6. Legs: Procoxae contiguous; prosternal coxal piece bulging. Protibiae distinctly triangular, posterior face smooth; apical 1/2 of outer margin with five large socketed denticles, their length much longer than basal width. Meso- and metatibiae flattened; outer margins obliquely triangular with six large socketed denticles.

Etymology.

The specific name refers to the Chinese province where it was collected. Latinized adjective.

Distribution.

China (Yunnan).

Host plants.

Unknown.

Figures

Figure 91. Dorsal, lateral and declivital view of Xyleborus singhi paratype, 1.9 - 2.4 mm (A, B, I), X. sunisae holotype, 2.7 - 2.75 mm (C, D, J), X. volvulus, 2.5 mm (E, F, K), and X. yunnanensis paratype, 2.7 - 2.75 mm (G, H, L).