Xyleborinus echinopterus, 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

Xyleborinus echinopterus sp. nov. Fig. 83C, D, J

Type material.

Holotype, female, China: Hong Kong, Shing Mun, 24-28.v.2017, ex intercept trap (IZAS).

Diagnosis.

3.0 mm long (n = 1); 2.73 × as long as wide. This species is distinguished by the posterior margin of elytra broadly rounded; declivital face with interstriae 1 and 2 unarmed by tubercles; declivital face weakly sulcate; large body size; lateral declivital margins elevated, bearing 2-4 pairs of small, narrow, sharply pointed spines of equal size (often asymmetric) on basal 2/3; sulcate area of declivity smooth, shiny; and stout body.

Similar species.

Xyleborinus artestriatus , X. ephialtodes , X. octiesdentatus , X. schaufussi , X. speciosus , X. spinipennis .

Description

(female). 3.0 mm long (n = 1); 2.73 × as long as wide. Body, legs, and antennae uniformly light brown. Head: epistoma entire, transverse, with a row of hair-like setae. Frons weakly convex to upper level of eyes, alutaceous, subshiny, finely, sparsely punctate, setose; punctures bearing a long, erect hair-like seta. Eyes shallowly emarginate just above antennal insertion, upper part smaller than lower part. Submentum large, distinctly triangular, deeply impressed. Antennal scape regularly thick, as long as club. Pedicel as wide as scape, as long as funicle. Funicle 4-segmented, segment 1 shorter than pedicel. Club longer than wide, obliquely truncate, type 1; segment 1 corneous, encircling anterior face; segment 2 narrow, concave, corneous on anterior face only; sutures absent on posterior face. Pronotum: 1.02 × as long as wide. In dorsal view basic and parallel-sided, sides parallel in basal 2/3, rounded anteriorly; anterior margin without serrations. In lateral view elongate, disc longer than anterior slope, type 7, summit low, on apical 2/5. Anterior slope with densely spaced narrow asperities, becoming lower and more strongly transverse towards summit, bearing long, fine, semi-recumbent, hair-like setae. Disc subshiny, alutaceous, finely punctate, finely setose, setae short, erect, hair-like, some longer hair-like setae at margins. Lateral margins obliquely costate. Base transverse, posterior angles acutely rounded. Elytra: 1.69 × as long as wide, 1.67 × as long as pronotum. Scutellum minute, conical, disconnected from elytra, surrounded by dense mycangial tuft of setae. Elytral base transverse, medially emarginate near scutellum and mycangial tuft, edge oblique, humeral angles angulate, parallel-sided in basal 3/4, then broadly rounded to apex. Disc occupying basal 3/5, smooth, shiny, glabrous, unarmed; striae not impressed, glabrous, with moderate punctures separated by one diameter of a puncture; interstriae flat, sparsely finely uniseriate punctate, punctures 1/3 those of striae, each bearing erect hair-like setae, setae approximately as long as width of interstriae 2. Declivital face steeply rounded, weakly sulcate between interstriae 3, smooth, shiny, striae and interstriae moderately setose, setae long, semi-erect hair-like, as long or longer than the distance between suture and interstriae 3; three striae present, striae 1 and 2 subcontiguous; strial punctures as larger, deeper than on disc; interstriae 1 and 2 flat, armed by two and four denticles, respectively, on declivital base, unarmed on face; interstriae 2 very narrow; interstriae 3 forming declivital margin, distinctly elevated, 2-4 pairs of small, narrow, sharply pointed spines of equal size (often asymmetric) on basal 2/3. Posterolateral margin rounded, denticulate from interstriae 3-7. Legs: procoxae contiguous, prosternal coxal piece flat, inconspicuous. Protibiae obliquely triangular, broadest at apical 1/3; posterior face smooth; apical 1/3 of outer margin with six moderate socketed denticles, their length approximately as long as basal width. Meso- and metatibiae flattened, outer margin evenly rounded with nine and seven moderate socketed denticles, respectively.

Etymology.

G. echinos - = hedgehog or sea urchin; - pteron = wing. In reference to the acute spines on the declivity. The last element has been Latinized as a second declension noun. A noun in apposition.

Distribution.

China (Hong Kong).

Host plants.

Unknown.

Figures

Figure 83. Dorsal, lateral and declivital view of Xyleborinus disgregus holotype, 1.8 - 2.0 mm (A, B, I), X. echinopterus holotype, 3.0 mm (C, D, J), X. ephialtodes holotype, 2.6 mm (E, F, K), and X. exiguus, 1.8 - 2.0 mm (G, H, L).