Amasa cycloxyster, 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 cycloxyster sp. nov. Fig. 7G, H, L

Type material.

Holotype, female, Thailand: Surat Thani, Khao Sok National Park, 22.iii.2006, Hulcr et al., ex "Mai Naun Pang" tree (MSUC).

Diagnosis.

3.4 mm long (n = 1); 3.4 × as long as wide. The species is distinguished by the pronotum appearing basic (type 2) when viewed dorsally, anterior margin serrate; declivital surface shagreened, dull, opaque; declivity glabrous; declivital interstriae 1-3 multiseriate granulate, granules strongly confused; and declivital interstriae convex.

Similar species.

Amasa galeoderma , A. resecta , A. schlichii , A. versicolor .

Description

(female). 3.4 mm long (n = 1); 3.4 × as long as wide. Body bicolored: pronotum, head, legs, antennae and abdomen orange, elytra dark 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, smaller, rounder, denser above epistoma, increasing in size and length and decreasing in density dorsally and laterally. 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, transverse on anterior face, occupying basal 1/5; segment 2 narrow, larger than segment 1, corneous; segments 1-3 present on posterior face. Pronotum: 1.08 × 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 five 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 shiny, alutaceous, impunctate, glabrous. Lateral margins obliquely costate. Base transverse, posterior angles narrowly rounded. Elytra: 1.4 × as long as wide, 1.3 × 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 ascending posteriorly, shiny, glabrous; striae and interstriae laterally diverging from base to declivital summit; striae not impressed, punctures separated by 1-4 diameters of a puncture; interstriae flat, finely punctate, punctures 1/2 the size of strial punctures, strongly confused. Declivity truncate, face convex, strongly shagreened, dull, glabrous; three striae present, striae moderately impressed, equidistant, strial punctures shiny, very large, shallow, much larger than on disc, punctures subcontiguous to spaced by two diameters of a puncture; interstriae impunctate, convex, interstriae 1 more strongly convex, interstriae 1-3 multiseriate granulate, granules strongly confused. Posterolateral margin forming a circumdeclivital carina, carina glabrous. Legs: procoxae contiguous; prosternal coxal piece bulging. Protibiae slender, broadest at apical 1/3; posterior face inflated, coarsely granulate; apical 1/2 of outer margin with six small socketed denticles, their length as long as basal width. Meso- and metatibiae broad, flattened, outer margins evenly rounded with 11 small and nine small to minute socketed denticles, respectively; posterior faces unarmed; anterior faces finely granulate.

Etymology.

G. kyklos = circle; xyster = rasp. In reference to acute granules on the round declivital face. A noun in apposition.

Distribution.

Thailand.

Host plants.

Unknown.

Remarks.

The holotype specimen is a DNA voucher, SAX40. The head and pronotum were separated from the specimen prior to DNA extraction and point mounted with the elytra.

Figures

Figure 7. Dorsal, lateral and declivital view of Amasa aspersa, 3.7 - 3.9 mm (A, B, I), A. beesoni paratype, 5.0 mm (C, D, J), A. concitata, 4.3 - 4.5 mm (E, F, K), and A. cycloxyster holotype, 3.4 mm (G, H, L).