Arixyleborus belalongi 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 : 5

Arixyleborus belalongi Smith, Beaver & Cognato sp. nov.

( Figs 9–12 )

http://zoobank.org/ urn:lsid:zoobank.org:act:061FF3E7-6B54-44BF-91E1-A961A95A6E7E

Type material. Holotype, female: BRUNEI [DARUSSALAM], Kuala Belalong FSC, E116.7', N4.34', Dipterocarp forest, Dipterocarpus beccarii, Aerial FIT 4, 270 m alt., 24.v.[19]91, N. Mawdsley, NM169, NHMUK014591833 (NHMUK) . Paratypes, female, as holotype except: Aerial FIT 2, 270 m alt., 4.vii.[19]91, NM222, NHMUK01838 (1, NHMUK) ; as previous except: Aerial FIT 4, 270m alt., 17.vii.[19]91, NM242 (1, RABC) ; as previous except: Aerial FIT 5, 255 m alt., 7.vi.[19]91, NM179, MSUC_ARC_314153 (1, MSUC) ; as previous except: 18.vii.[19]91, NM240, NHMUK01840 (1, NHMUK); as previous except: Aerial Malaise 6, 275m alt., 3.vii.[19]91, NM213 (1, RABC) .

Diagnosis. This species is distinguished by the protibiae posterior faces inflated, granulate; antennal club wider than long; pronotum lateral margin oblique; pronotum anterior margin without serrations; posterolateral carina acute, carinate; declivital interstriae 1 strongly elevated on apical half, denticulate on apical half; and discal interstriae 1–6 ending in small triangular teeth projecting over the declivity.

The species is closely related to A. suturalis ( Eggers, 1936) , but can be distinguished by the whole of the elytral disc and declivity shining, not matte posteriorly; the posterior part of the elytral disc with the striae more deeply grooved, and interstriae 1–6 ending in small triangular teeth projecting over the declivity; sutural interstriae without denticles on upper half of declivity, remaining declivital interstriae without granules and long hairs.

Similar species. Arixyleborus suturalis , A. minor ( Eggers, 1940)

Description (female). 1.5–1.7 mm long (mean = 1.6 mm; n = 4); 2.5–2.91 × as long as wide. Pronotum dark brown, legs and antennae yellow-brown, elytra bicolored: basal half of disc brown, posterior half of disc and declivity reddish brown. Head: epistoma entire, transverse, lined with a row of hair-like setae. Frons slightly convex from epistoma to upper level of eyes; surface alutaceous, dull, impunctate; punctures above epistoma large, coarse. Eyes deeply emarginated above level of antennal insertion, upper portion of eyes smaller than lower part. Submentum flat, deeply impressed below genae, shaped as a large triangle. Antennal scape short and thick, about as long as club. Antennal funicle 4-segmented, segments equal in size. Pedicel as long as funicle. Club wider than long, obliquely truncate, type 2 with segment 1 covering basal half of anterior face and most of posterior face, its margin completely costate, segment 2 narrow, pubescent with corneous part, visible on anterior face only. Pronotum 1.17–1.33 × as long as wide. In dorsal view very elongate and rounded frontally, type 9, sides parallel on basal 2/3; anterior margin without serrations. In lateral view elongate with disc much longer than anterior slope, type 8, disc flat, summit at apical 1/3. Anterior slope shagreened, with densely spaced, fine, narrow asperities, becoming lower and more strongly transverse towards summit, bearing long, fine, semi-recumbent, hair-like setae. Disc subshiny, alutaceous, sparsely finely punctate. Lateral margins obliquely costate. Base transverse, posterior angles strongly oblique. Scutellum moderately sized, ‘u’ shaped, flat, flush with elytra. Elytra: 1.42 × as long as wide, 1.33–1.48 × as long as pronotum, shining. Base feebly concave, humeral angles rounded. Sides straight from base to apical 3/4; lateral profile of declivity obliquely truncate; apex angulate, entire. Disc occupying 3/4 of declivity; anterior half of disc with interstriae smooth, nearly glabrous, finely, sparsely punctate; posterior half with striae more deeply grooved, and interstriae 1–6 ending in small triangular teeth projecting over the declivity. Declivital interstriae 1 strongly elevated on apical half, denticulate; interstriae impunctate; strial punctures very large, glabrous; dorso- and lateral margins ornamented with long incurved setae arising from each tooth projecting over the declivity and on the interstriae. Posterolateral declivital margin acute, carinate, laterally extending to interstriae 7. Legs: Procoxae contiguous. Protibiae slender, broadest at apical third, posterior face inflated, tuberculate; five large socketed denticles present on outer margin of apical half. Meso- and metatibiae with evenly rounded outer margins, flattened, posterior faces unarmed, seven small socketed denticles present on outer margin.

Distribution. Brunei Darussalam.

Host plants. Unknown.

Etymology. In reference to the collection locality, Kuala Belalong. An adjective.

Figures

FIGURES 9‒12. Arixyleborus belalongi holotype, 1.7 mm. Dorsal, lateral, posterior oblique and anterior views.