Planiculus angulatus Sittichaya & Cognato, 2024

Sittichaya, Wisut & Cognato, Anthony I., 2024, Planiculus angulatus, a new species of xyleborine ambrosia beetle from Thailand (Coleoptera, Curculionidae, Scolytinae, Xyleborini), Zootaxa 5471 (4), pp. 482-488 : 483-485

Planiculus angulatus Sittichaya & Cognato sp. nov.

( Fig. 1 )

Type material. Holotype, female: THAILAND: Yala Province, Betong District, Betong-National Forest Reserve , 5°48’43.9”N 101°16’33.4”E, 1390m, low montane forest, ex branch of unknown tree, 07.iv.2024, W. Sittichaya ( NHMW); paratypes, (5) as holotype (1, RABC; 1, MSUC; 1, THNHM; 2, WSTC).

Diagnosis: 1.85–1.86 mm long (mean 1.85, n = 5); 2.99–3.06× as long as wide. Pronotum from dorsal view type 7 long and apically rounded, anterior slope longer than disc. Elytra elongate, 1.89–194× as long as wide, 1.67–1.83× as long as pronotum. Declivity matt, unarmed by tubercles, lateral margin broadly rounded angulate, apex shallowly emarginate. The more strongly angulate apex of the elytral declivity distinguishes P. angulatus from the most morphologically similar P. bicolor .

Description (female). 1.85–1.86 mm long (mean 1.85, n = 5); 2.99–3.06× as long as wide. Body strongly shiny, except declivity matt, distinctly separated from the disc; color dark brown to black, appendages and notal ventrite paler; spare vestiture. Head. Epistoma complete, anterior margin transverse, with a row of hair-like setae, setae short, sparse. Frons feebly convex to upper level of eyes, surface alutaceous (near epistoma weakly reticulate, rugulosepunctate in some paratypes), shiny, rather sparsely punctured, punctures moderate sized, moderately deep, each with long, fine hair-like setae; some minute granules present near epistoma; frons with weakly elevated glabrous, median line; setae along lateral margin of the eyes distinctly longer than on the frons. Eyes shallowly emarginate just above antennal insertion, upper part distinctly smaller than lower part. Submentum narrow triangular, small, shallowly impressed. Antennal scape thickened and moderately long, slightly longer than club. Pedicel narrower than scape, 2× shorter than funicle. Funicle 4-segmented, segment 1 shorter than pedicel. Club nearly circular, slightly wider than long (6:5), type 2; segment 1 corneous, segment 2 visible on posterior side; segment 1 on anterior face occupying basal half, margin straight, transverse, sharp carinate, segment 2 appearing soft. Pronotum. 1.05–1.13× as long as wide, from dorsal view type 7 long and apically rounded, anterior slope longer than disc, from lateral view type 7 elongated, with low summit. Anterior slope slightly flattened laterally, anterior slope dense asperities; asperities broad, low, surface between asperities alutaceous, subshiny, very sparsely setose; setae short, some longer setae present on margin; the first row of asperities near anterior margin arrange in line, asperities distinctly larger and more elevated than asperities following behind, asperities becoming lower and more strongly transverse towards summit. Pronotal disc alutaceous, shiny, sparsely punctate; puncture fine, shallow, each with very short, fine seta; disc with narrow, glabrous, shiny medial line. Pronotal posterior margin weak concave. Pronotal lateral margin obliquely costate. Elytra. Much elongate, 1.89–194× as long as wide, 1.67–1.83× as long as pronotum. Scutellum moderate sized, linguiform, flat, flush with elytra, surface finely punctate, shiny. Elytral bases transverse, edge costate, feebly elevated, humeral angles rounded. Sides straight from base to apical 4/5, then broadly angulated to apex. Apex minutely emarginate. Disc strongly shiny, strongly convex, excepted posterior of scutellum flattened; striae punctate; puncture moderate sized, very deep, punctures separated by twice of puncture diameter, each with a short, very fine, seta; setae slightly longer than a diameter of a puncture, recumbent, hair-like (almost obliterate in holotype and some paratypes); interstriae flat, twice as wide as striae, punctate, punctures uniseriate, fine, setose, setae very fine, long, erect, hair-like (some obliterate in holotype and some paratypes); declivity shagreen, matt, distinctly separate from disc, declivity gradually descending to apical 1/3 of declivital face then transversely abruptly concave to apex. Declivital striae flat, twice as wide as interstria, punctate; punctures minute, shallow, inconspicuous, separated by twice puncture diameter. Interstriae feebly elevated, with a row of densely placed granules; granule minute, interstria with short scale-like setae. Posterolateral margin carinate to interstria 7, armed with small granules. Legs. Procoxae contiguous. Protibiae distinctly triangular, broadest at apical 1/3, outer margin with four comparatively large socketed denticles, their length longer than basal width; posterior face inflated, unarmed. Mesotibiae large, triangular, outer margin with eight medium sized socketed denticles, posterior face inflated; metatibiae evenly rounded, smaller than metatibia; outer margins with small ten socketed denticles.

Male. Unknown.

Etymology. Latin adjective, angulatus = with angles; referring to the form of its elytral apex.

Distribution. THAILAND: Yala Province.

Figures

FIGURE 1. Planiculus angulatus sp. nov. holotype female A) lateral view B) dorsal view C) postero-lateral view D) frons E) antenna.