Amasa lini, Smith & Beaver & Cognato, 2020

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China, ZooKeys 983, pp. 1-442 : 1

Amasa lini sp. nov. Fig. 9A, B, I

Type material.

Holotype, female, Taiwan: Nantou Dist., Sun Moon Lake, 23.vi.2016, C.-S. Lin (TARI).

Diagnosis.

3.5 mm long (n = 1); 2.33 × as long as wide. This species is distinguished by the pronotum appearing basic (type 2) when viewed dorsally, anterior margin serrate; declivital surface smooth, shiny; large size; declivity glabrous; declivital interstriae 1 strongly tumescent and granulate; declivital striae 1 strongly laterally displaced, nearly touching striae 2, striae 3 displaced to near circumdeclivital carina margin; and declivital striae 2 not appearing equidistant between striae 1 and 3.

Similar species.

Amasa concitata , A. gibbosa , A. tropidacron , A. youlii .

Description

(female). 3.5 mm long (n = 1); 2.33 × as long as wide. Body bicolored: pronotum reddish, elytra and abdomen dark brown, head, legs, and antennae light brown. Head: epistoma entire, transverse, with a row of hair-like setae. Frons weakly convex to upper level of eyes; median impression between eyes; surface shagreened, impunctate, alutaceous, asperate; asperities longitudinal, larger, rounder, denser above epistoma, increasing in length and decreasing in width and density dorsally. Eyes very deeply emarginate just above antennal insertion, upper part smaller than lower part. Submentum triangular, deeply impressed. Antennal scape regularly thick, as long as club. Pedicel as wide as scape, shorter than funicle. Funicle 4-segmented, segment 1 shorter than pedicel. Club approximately circular and flat, type 4; segment 1 corneous, sinuate on anterior face, occupying approximately 1/5 of club; segment 2 narrow, larger than segment 1, corneous; segments 1-3 present on posterior face. Pronotum: 1.4 × as long as wide. In dorsal view basic and parallel-sided, type 2, sides parallel in basal 1/2, rounded anteriorly; anterior margin with a row of eight serrations. In lateral view basic, type 0, disc flat, summit at midpoint. Anterior slope shagreened, with densely spaced, fine asperities, becoming lower and more strongly transverse towards summit, bearing long, fine, semi-recumbent hair-like setae. Disc subshiny, alutaceous, densely, finely punctate, glabrous. Lateral margins obliquely costate. Base transverse, posterior angles broadly rounded. Elytra: 1.4 × as long as wide, 1.43 × as long as pronotum. Scutellum moderately sized, broad, linguiform, flush with elytra, flat, shiny. Elytral base transverse, edge oblique, humeral angles rounded, parallel-sided in basal 3/4, then sharply angulate to apex. Disc flat, shiny, glabrous; striae and interstriae laterally diverging from base to declivital summit; striae not impressed, punctures separated by 3-5 diameters of a puncture; interstriae flat, finely punctate, punctures 1/3 size of strial punctures, strongly confused. Declivity truncate, face convex, smooth, shiny, glabrous; three striae present, striae weakly impressed, striae 1 strongly laterally displaced, striae 2 nearly touching striae 1, striae 3 displaced to near circumdeclivital carina, strial punctures dull, small, shallow, larger than on disc, punctures spaced by a diameter of a puncture; interstriae impunctate, convex, interstriae 1 strongly tumescent and granulate, granules strongly confused, apical 1/6 of interstriae 1 carinate. Posterolateral margin forming a circumdeclivital carina; carina glabrous. Legs: procoxae contiguous, prosternal coxal piece flat, inconspicuous. Protibiae slender, broadest at apical 1/3; posterior face inflated, finely granulate; apical 1/2 of outer margin with five small socketed denticles, their length as long as basal width. Meso- and metatibiae broad, flattened, outer margins evenly rounded with 11 and nine small socketed denticles, respectively, posterior faces unarmed; anterior faces finely granulate.

Etymology.

The species is named for Mr. Ching-Shan Lin, the collector, for his contributions to our knowledge of bark and ambrosia beetles. Noun in genitive.

Distribution.

Taiwan.

Host plants.

Unknown.

Figures

Figure 9. Dorsal, lateral and declivital view of Amasa lini holotype, 3.5 mm (A, B, I), A. opalescens lectotype, 4.5 - 4.8 mm (C, D, J), A. resecta, 2.85 - 3.2 mm (E, F, K), and A. schlichii, 2.9 - 3.5 mm (G, H, L).