Xylodrypta lanna Liu and Beaver, 2021

Liu, Lan-Yu, Beaver, Roger A. & Sanguansub, Sunisa, 2021, Revision of the genus Xylodrypta Lesne 1901 (Coleoptera: Bostrichidae: Bostrichinae: Xyloperthini) with a new species and a key to species, Zootaxa 5005 (2), pp. 234-240 : 236-237

Xylodrypta lanna Liu and Beaver , sp. n.

( Figs 1‒2 )

Type material. Holotype: Male: THAILAND, Chiang Mai, Doi Pui, Khun Chang Highland Research Station . N18°50′ 23.11′′, E98°53′53.31′′, EtOH trap, c. 1300m, 7.i.2015, S. Sanguansub (currently in LYL, to be deposited in NHML) . Allotype: Female: same data as for the holotype (currently in LYL, to be deposited in NHML) . Paratypes: same data as for the holotype (1♂, 1♀ KSU; 2♂, 2♀ LYL; 1♀ NME; 1♂ RAB) ; as previous but: 18 o 50′23′′N, 98 o 53′53′′E, 1200‒1300m, 29.i.2014, T. Saowaphak (2♂ RAB) ; as previous but 12.ii.2014 (1♂ RAB) ; Chiang Mai, Doi Suthep , i.2006, S.Sonthichai (1♀ RAB) ; Nan, Doi Phukha National Park, Lower Hill Evergreen Forest , eBT, 19°10'24.5"N 101°06'22.7"E, 01.xii.2019, W. Sittichaya (1♂ WST) ; NE LAOS, Hua Phan Prov. , Mt. Phu Pane , 1200‒1600m, 10-22. V. 2011, 20 o 12′N 103 o 59′E, St. Jaki and Lao collectors lgt. (1♂ NME) .

Diagnosis. The species can be distinguished from X. bostrychoides by the characters given in the key above.

Description. Male ( Fig. 1 )

Body. 5.7‒7.5 mm in length (mean = 7.0 mm, n = 7), 2.92‒3.43 times longer than wide. Generally brown, antennae yellowish, anterior slope of pronotum dark brown, elytra becoming dark brown to black posteriorly, legs pale with darker tibiae.

Head moderately convex. Frons densely granulate-punctate in a broadly triangular, median area above clypeus, becoming longitudinally rugose dorsally and laterally, the punctures bearing long, fine, erect hairlike setae, the longest setae next to inner margin of eyes, becoming shorter and semi-appressed towards middle, directed toward mid-line, the shortest setae along upper margin of setose area and directed ventrally ( Fig. 1D ). Fronto-clypeal suture shining with a small, deep impression at middle. Clypeus with thickened, nearly impunctate and shining margins and at middle, moderately densely punctured on each side of middle, pubescence long, fine and directed slightly dorsally. Labrum finely, very densely punctured, with fine, ventrally directed setae, the setae becoming longer and coarser close to apical margin ( Fig. 1D ). Antennae with ten antennomeres, funicle short, antennomeres 3‒7 becom- ing progressively more transverse, their total length slightly more than first antennomere of club, antennal club matt, first and second club antennomeres almost equally long, each with a pair of indistinct sensory areas near apex, third antennomere of club about 1.5 times longer than each of the previous two, its width about 0.8 times that of the penultimate antennomere ( Fig. 1D ).

Pronotum 1.1‒1.4 times wider than long, widest slightly before base, sides broadly, strongly converging anteri- orly from the middle ( Fig. 1B ), with a pair of upwardly-directed, uncinate teeth on antero-lateral angles, three pairs of smaller teeth behind first pair along the antero-lateral margin ( Figs 1A, B ); asperities on anterior slope smaller, closer, and more concentrically arranged towards summit of pronotum ( Fig. 1A ); pronotal disc smooth and shining with very sparse, minute punctures, the punctures denser and bearing very short, fine hairs towards posterior angles, some tiny asperities behind summit ( Figs 1A, B ); posterior angles broadly rounded, projecting slightly posteriorly, without a lateral carina; basal margin sinuate ( Fig. 1A ).

Scutellum tongue-shaped, finely punctate.

Elytra parallel-sided, 1.95‒2.2 times longer than wide, basal margin sinuate, almost glabrous except for the lateral and apical margins with sparse, short, white pubescence, puncturation of disc relatively finer and sparser near base, becoming coarser and denser posteriorly ( Figs 1A, B ); three slightly raised costae, the first along the suture, the second and third each separated by 3‒4 rows of punctures from the first, extend from elytral base to the first three pairs of spines on upper margin of elytral declivity; apex of first costa with a small pointed tubercle, apex of 2 nd and 3 rd costae each with a conical, pointed spine, that of 3 rd costa larger than that of 2 nd costa; below these a larger, more broadly triangular, slightly incurved spine on lateral margin of declivity, all four spines on each elytron about equally separated from each other ( Figs 1A, B ); elytral declivity with strongly raised lateral margin in its lower half ( Figs 1B, C ), puncturation denser and coarser than on disc, the punctures subcircular and of almost equal size over the whole declivity, interspaces between the punctures smooth, shining ( Fig. 1E ); suture raised on declivity, the elevation parallel-sided and punctured, not swollen, but more strongly raised close to apex; declivital surface weakly, irregularly impressed on each side of suture, and close to lateral margins ( Fig. 1E ).

Abdomen. Abdominal ventrites very finely, densely punctured, vestiture of long, fine, whitish, recumbent hairs; 1 st to 4 th ventrites transverse and last ventrite evenly convex with distinct pleural piece tapering to a narrow point near the midline along posterior margin ( Fig. 1C ), posterior part with longer whitish hairs converging towards midline.

Female ( Fig. 2 ). 6.4‒7.5 mm long (mean = 6.89 mm, n = 13), 2.87‒3.42 times as long as wide. Resembling male but brush of setae on frons longer and the setae directed ventrally near upper margins of median area, and towards mid-line near its lateral margins, remainder of frons with sparse, short, semi-appressed setae directed ventrally, a weakly raised median line sometimes present ( Fig. 2C ). Posterior margin of fourth visible ventrite thickened and slightly produced in an arc in middle third, and bearing a dense fringe of setae; on each side of thickened margin, a pair of strong, hook-like processes, each arising from a broadly triangular, concave base, the basal part of the hook directed ventrally, but its apical half curved round so that the sharply pointed tip is directed dorsally ( Figs 2B, D ); last ventrite strongly curved at sides, posterior margin sclerotised, thickened, becoming thinner and sinuate toward middle between hooks of 4 th ventrite, the thinner middle part strongly concave to form a transverse arc ( Figs 2A, D ).

Etymology. The species is named after the old Northern Thai Kingdom, Lan Na, which included the locations where almost all specimens of the new species were collected. It should be treated as a noun in apposition to the generic name.

Distribution: Northern Thailand, Northeastern Laos.

Remarks: All specimens were collected at 1200m altitude or above. It appears that this is a montane species.

Figures

FIGURE 1. Xylodrypta lanna Liu & Beaver, sp. n., male paratype (LYL). A. Dorsal view. B. Lateral view. C. Ventral view. D. Front view of head and right antenna. E. Posterior view of elytral declivity. Scale bar = 1mm, the left bar refers to A‒C, the right bar to D and E.

FIGURE 2. Xylodrypta lanna Liu & Beaver, sp. n. female paratype (LYL).A. Ventral view. B. Latero-ventral view of abdomen. C. Fronto-lateral view of head and pronotum. D. Ventral view of abdomen. Scale bar = 1mm, the lower bar refers to C and D.