Xyleborinus nobuchii Smith, Beaver & 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 : 21-22

Xyleborinus nobuchii Smith, Beaver & Cognato sp. nov.

( Figs 69–72 )

http://zoobank.org/ urn:lsid:zoobank.org:act:CB76DB7C-26ED-4674-8985-E8377F10C5C0

Type material. Holotype, female: JAPAN, Kagoshima Pref., Tarumizu Oonohara, Broadleaf forest , 425m, 5 November 2001, Yoshikazu Sato coll, ex ETOH-baited trap ( NUFM) . Paratypes, as holotype except: 17 July 2000 (1, NMNH) ; 1 Aug 2000, MSUC_ARC_314127 (1, MSUC) .

Diagnosis. This species is distinguished by the entire length of interstriae 2 unarmed by tubercles; elytra attenuate from basal half, apex acute; declivital interstriae flat, interstriae 2 not impressed; and denticles on interstriae 1 and 3 moderate.

Similar species. Xyleborinus perpusillus ( Eggers, 1927)

Description (female). 2.2 mm long (mean = 2.2 mm; n = 3); 3.38 × as long as wide. Body red 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, subshiny, finely, moderately punctate, setose; punctures each with a long, erect hairlike seta. Eyes shallowly emarginate just above antennal insertion, upper part smaller than lower part. Submentum large, distinctly triangular, deeply impressed. Antennal scape short and thick, shorter than club. Pedicel as wide as scape, shorter than funicle. Funicle 4-segmented, segment 1 shorter than pedicel. Club longer than wide, obliquely truncate, type 1; segment 1 corneous, occupying basal 3/5 and encircling anterior face; segment 2 narrow, concave, corneous on anterior face only; sutures absent on posterior face. Pronotum 1.23 × 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 much longer than anterior slope, type 7, summit prominent, on anterior 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 shiny, 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: 2.15 × as long as wide, 1.75 × as long as pronotum. Base transverse, medially emarginate near scutellum and mycangial tuft, edge oblique, humeral angles rounded, attenuate from basal half, apex acute. Disc occupying basal ~2/3, smooth, shiny, unarmed; striae not impressed, glabrous, with small punctures separated by 1–2 diameters 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 strongly shagreened, gradually sloping, three striae present, striae 1 and 2 subcontiguous, strial punctures minute, shallow, glabrous; interstriae impunctate, denticulate, setose, setae uniseriate, variably sized, setae between denticles from as long as a denticle, setae as base of a denticle 2 × as long as a denticle; interstriae 1 with a row of with six or seven small to moderate denticles along its length; interstriae 2 flat, extremely narrow, nearly obsolete, unarmed along its entire length; interstriae 3 with a row of 4–6 small to moderate denticles along its length, their apices acutely pointed, spine-like. Posterolateral margin rounded, denticulate from interstriae 3–5. Legs: procoxae contiguous. Protibiae obliquely triangular, broadest at apical 1/3; posterior face smooth; apical 1/3 of outer margin with five moderate socketed denticles, their length approximately as long as basal width. Meso- and metatibiae flattened; outer margin evenly rounded with eight and seven moderate socketed denticles, respectively.

Distribution. Japan (Kyushu).

Host plants. Unknown.

Etymology. Named in honor of the Japanese scolytid taxonomist Akira Nobuchi. Noun in apposition.

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).