Anthicomorphus langbiang, Telnov, 2024

Anthicomorphus langbiang sp. nov. ( Figs 1–3 View Fig View Fig View Fig )

urn:lsid:zoobank.org:act:60764417-93FA-4387-85EF-E01BED4B88C1

Type material designated. Holotype ♂ NME: S-Vietnam, Lam Dong Pr., Lac Duong Distr., Bidoup Nui Ba national park, vic. station at Da Nhim river [printed] // 12°10'58''N, 108°40'48''E) to Deo Khane Pass (12°11'11''N, 108°42'53''E). 22.- 26.IV.2024 1450-1650m.leg. A.Weigel LF [printed]. GoogleMaps

Paratypes 3 specimens. 1♀ NME : same label as holotype; 1♀ ASC & 1♀ DTC: S–

2

Derivatio nominis. Toponymic. Named after the Lang Biang Plateau where this species occurs.

Measurements, holotype male, total body length 4.1 mm; head length 0.9 mm, head width across compound eyes 0.8 mm, pronotal length 0.9 mm, maximum pronotal width across anterior lobe 0.7 mm, minimum pronotal width 0.4 mm, elytral length 2.3 mm, combined maximum elytral width across postmedium 1.2 mm. Selected female paratype, total body length 4.7 mm; head length 0.9 mm, head width across compound eyes 0.75 mm, pronotal length 0.9 mm, maximum pronotal width across anterior lobe 0.75 mm, minimum pronotal width 0.4 mm, elytral length 2.9 mm, combined maximum elytral width across postmedium 1.4 mm.

3 Description. Holotype male ( Figs 1 View Fig , 3 View Fig ). Dorsal forebody dark brown. Elytra generally dark brown dorsally, broadly pale brown laterally, a paired small elliptical spot posteriad to postbasal transverse impression (isolated from pale brown lateral area of elytron) and a large common preapical subrectangular spot which is narrowly connected at its posterior extent to pale brown lateral area of each elytron yellow to yellowish brown (always distinctly paler than brown lateral portion of elytron); elytral apex dark brown ( Fig. 1A View Fig ). Mouthparts and antenna yellowish, three to four terminal antennomeres slightly darkened. Legs yellowish to yellowish rufous, tibia darkened in distal half, metathoracic legs generally slightly darker than pro- and mesothoracic pair. Ventral forebody and mesosternum pale brown, metasternum black-brown, abdomen brown to dark brown. Head elliptical, slightly longer than wide, slightly convex in dorsal aspect, subopaque. Labrum subtruncate at anterior margin. Frontoclypeal suture not indicated. Compound eye large, nearly holoptic, strongly protruding from lateral and dorsal outline of head, about 1.8× as long as strongly converging tempus. Head base narrow, rounded. Head dorsal punctures dense, moderately deep. Intervening spaces much narrower than puncture diameters, smooth and moderately glossy. Dorsal cranial setae yellowish to golden, dense, appressed, in part effectively concealing dorsal sculpture of head, arranged transversely on vertex, pointed longitudinally anteriad along inner eye margin and obliquely anteriorly along median portion of frons. Antenna exceeds midlength of metasternum when directed posteriad, not thickened apically. Basal antennomere elongate and thickened, asymmetrically cylindrical, impressed at posterior edge facing compound eye, about 2.5× as long as second antennomere. Second antennomere short, hardly longer than wide. Third antennomere, longest among

4 antennomeres 2–10, about 3.2× as long as second antennomere, hardly longer than fourth antennomere. Antennomeres 4–10 thickened distally, slightly asymmetrical (distal portion widened somewhat disproportionally stronger at one lateral edge). Penultimate antennomere distinctly longer than wide. Terminal antennomere elongate, asymmetrical, apically pointed, about 1.8–1.9× as long as penultimate antennomere, slightly shorter than combined length of antennomeres 9–10. Penultimate maxillary palpomere subtriangular, with strong lateral lobe at anterior margin. Terminal maxillary palpomere scalene triangular. Mandible strongly widened at basal portion. Pronotum longer than wide, slightly narrower than head across eyes, shortly truncate medially at anterior margin. Pronotal disc subopaque, nearly flat in dorsal aspect. Dorsal outline of pronotum hourglass shaped, lateral margins strongly constricted laterally postmedium, those of anterior lobe rounded laterally, of posterior lobe – slightly widened towards base. Anterior pronotal rim and antebasal sulcus distinct, wide dorsally, laterally and ventrally. Pronotal dorsal and lateral punctures larger and less regularly shaped than those on head. Intervening spaces much narrower than puncture diameters, smooth and moderately glossy. Pronotal setae yellowish to golden, dense, appressed, in part effectively concealing dorsal sculpture of pronotal disc, directed posteriad or (on lateral constriction area) – obliquely medio-posteriad. Some significantly longer erect tactile setae present on disc and lateral sides. Scutellar shield small, lanceolate, apically slightly pointed, moderately glossy, with short setae. Elytra elongate, about 1.9× as long as wide, widest around midlength, dorsally slightly convex in apical two thirds. Postbasal transverse impression shallow but distinct. Humerus broadly rounded but distinct, humeral callosity weakly developed. Apical sutural angle rounded. Elytral surface moderately glossy and smooth, dorsal punctures elliptical, moderately deep and rather dense. Intervening spaces smooth and glossy, about twice as wide as puncture diameters, denser along suture. Elytral setae moderately long, rather dense, appressed, setae on dark background dark golden to brown (except for some pale golden setae on basal fourth), setae on paler background contrastingly paler golden to yellow. Scattered, longer erect tactile setae on elytral disc and lateral edges. Metathoracic wing fully developed (functional). Legs long and slender, densely setose. Tibial terminal spurs short, paired, strongly subequally long (spur at posterior tibial margin always short, inconspicuous). Penultimate tarsomere bilobate. Basal metatarsomere slightly longer than combined length of remaining metatarsomeres. Last visible abdominal tergite exposed, not concealed by elytra. Tergite VII subtruncate at posterior margin

( Fig. 3A View Fig ). Sternite VII rounded at posterior margin, here medially with two long and several somewhat shorter setae ( Fig. 3B View Fig ). Tergite and sternite VIII as in fig. 3C–D. Sternite IX with short arms ( Fig. 3E View Fig ). Aedeagus as in fig. 3F, inner sac without gonopore armature.

Sexual dimorphism. Female ( Figs 2–3 View Fig View Fig ) slightly longer, compound eye about 2.6– 2.7× as long as comparatively less strongly converging tempus. Female basal antennomere about 2.5× as long as second antennomere. Second antennomere hardly longer than wide. Third antennomere twice as long as second, about 1.3× as long as fourth antennomere. Terminal antennomere nearly twice as long as penultimate, antennomeres 9–10 nearly equally long. Female basal metatarsomere slightly longer than combined length of remaining metatarsomeres. Tergite VII narrowly rounded at posterior margin ( Fig. 3G View Fig ). Sternite VII subangulate medially at posterior margin, here with two long setae

( Fig. 3H View Fig ). Sternite IX rod-like ( Fig. 3I View Fig ).

Differential diagnosis. The new species is peculiar among all congeners primarily due to the elytral colouration and no similarly coloured Anthicomorphus species are yet known. Anthicomorphus pasteuri Pic, 1901 (Java, Sumatra) has the elytra ochrecoloured with large, irregularly][-shaped black to dark brown median spot expanding towards the lateral margins (but not touching them) at its anterior and posterior extent, narrower medially; the anterior margin of dark spot touches the base of elytra, the posterior margin subtruncate to slightly sinuous. Anthicomorphus rufithorax Pic, 1909 (Peninsular Malaysia, Singapore, Thailand, Vietnam) has the dorsal forebody pale and the elytra with the large dark median spot along the suture. Anthicomorphus dohertyi Pic, 1910 (New Guinea) and A. serricornis (Marseul, 1882) (Sumatra) are both dark rufous dorsally and ventrally, elytra with a large black spot leaving only shoulders, apex and a narrow lateral edge of each elytron rufous, at least the antennomeres 4–10 are black in these two species. Anthicomorphus obscurus Krekich-Strassoldo, 1928 ( Thailand, Vietnam, unpublished record from Peninsular Malaysia) is significantly smaller and entirely dark brown except for the paler elytral apex). The new species, besides the colour pattern, is specific also in the combination of the following features: the intermediary antennomeres only slightly asymmetrical, not serrate, the head base not strongly prolonged posteriad, the dorsal forebody densely punctured, subopaque, the metasternum distinctly darker than the pro- and mesosternum, the shape of the aedeagus is different.

Ecology. Attracted to light at 1450–1650 m a.s.l. in a primary mid-montane rainforest.

Distribution. So far known from the Lang Biang Plateau (also known as Lâm Viên or Đà Lạt Plateau), southern Vietnam.

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