Xyleborinus dumosus Smith, Beaver, Pham & Cognato, 2022

Smith, Sarah M., Beaver, Roger A., Pham, Thai Hong & Cognato, Anthony I., 2022, New species and new records of Xyleborini from the Oriental region, Japan and Papua New Guinea (Coleoptera: Curculionidae: Scolytinae), Zootaxa 5209 (1), pp. 1-33 : 20

Xyleborinus dumosus Smith, Beaver, Pham & Cognato sp. nov.

( Figs 65–68 )

http://zoobank.org/ urn:lsid:zoobank.org:act:5183F61A-E30B-4213-8D9E-DA2418C755D4

Type material. Holotype, female: VIETNAM, Lao Cai Prov., Hoang Lien N.P., 22.35N, 103.77E, 1500–2000m, 19.v.2019, VN177, SM Smith, AI Cognato, ex 3–5 cm branch, SAX 434 [DNA voucher], MSUC_ARC_314129 ( MSUC).

GenBank. CAD: OP607184 and COI: OP617755 .

Diagnosis. This species is distinguished by the posterior margin of elytra broadly rounded; declivital face with interstriae 1 and 2 unarmed by tubercles; declivital face moderately sulcate, striae punctate; lateral declivital margins feebly elevated, bearing 6–8 pairs of minute to small, narrow, sharply pointed and recurved spines (often asymmetric) on basal 2/3 of declivity; and sulcate area of declivity shagreened, dull.

Similar species. Xyleborinus acanthopteron sp. nov., X. echinopterus , X. octiesdentatus , X. kwangruengensis

Description (female). 2.9 mm long (n = 1); 2.9 × as long as wide. Body uniformly dark brown, legs and antennae yellow brown. Head: epistoma entire, transverse, with a row of hair-like setae. Frons weakly convex to upper level of eyes, alutaceous, dull, densely, coarsely punctate, setose; punctures each 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 1.11 × as long as wide. In dorsal view basic and parallel-sided, type 2, 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. Scutellum minute, conical, disconnected from elytra, surrounded by dense mycangial tuft of setae. Elytra: 1.9 × as long as wide, elytra 1.9 × as long as pronotum. 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 2/3, smooth, shiny, glabrous, unarmed; striae not impressed, glabrous, with moderate punctures separated by 1–2 diameters of a puncture; interstriae flat, sparsely finely uniseriate punctate, punctures 1/3 as large as those of striae, each bearing an erect hair-like seta, setae approximately as long as width of interstriae 2. Declivital face steeply rounded, moderately sulcate between interstriae 3, shagreened, dull, striae and interstriae feebly setose, setae long, semi-erect hair-like, as long as the distance between suture and interstriae 3 on declivital margins and semi-erect and no longer than an interstriae 2 width on declivital face; three striae present, striae 1 and 2 in irregular rows; strial punctures as larger, deeper than on disc; interstriae 1 and 2 flat, armed by two and three denticles, respectively on declivital base, unarmed on face; interstriae 2 punctate, punctures as described for striae; interstriae 3 forming declivital margin, feebly elevated, 6–8 pairs of minute to small, narrow, sharply pointed and recurved spines (often asymmetric) on basal 2/3. Posterolateral margin rounded, spinose from interstriae 3–7. Legs: procoxae contiguous, prosternal coxal piece inflated. Protibiae obliquely triangular, broadest at apical 1/3; posterior face smooth; apical 1/3 of outer margin with seven moderate socketed denticles, their length approximately as long as basal width. Meso- and metatibiae flattened, outer margin evenly rounded with eight or nine and nine moderate socketed denticles.

Distribution. Vietnam.

Host plants. Unknown.

Etymology. L. dumosus = covered with thornbushes. In reference to the spiny elytral declivity. A variable adjective.

Figures

FIGURES 61‒72. Lateral, dorsal, posterior oblique and anterior view of Xyleborinus acanthopteron holotype, 2.5 mm (61–64), Xyleborinus dumosus holotype, 2.9 mm (65–68), Xyleborinus nobuchii holotype, 2.2 mm (69–72).