Amasa gibbosa, 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 gibbosa sp. nov. Fig. 8G, H, L

Type material.

Holotype, female, Thailand: Kanchanaburi, Thong Pha Phoom Dist., Phu Yae subdist[rict], 400 m, 14.944N, 98.674E, 16.vii.2002, Cognato, Gillogly, Harlin (MSUC). Paratypes, female, as holotype (MSUC, 1; NHMUK, 1; RABC, 1); Suratthani, Khao Sok N.P., 1.ii.2015, 19°21'41.8"N, 98°55'03.4"E, W. Sittichaya, ex ethanol baited trap, tropical rain forest (MSUC, 1).

Diagnosis.

3.5-3.6 mm long (mean = 3.53 mm; n = 3); 2.33-2.41 × as long as wide. This species is distinguished by the pronotum appearing basic (type 2) when viewed dorsally, anterior margin serrate; declivital surface glabrous, smooth, strongly shiny; moderate size; declivital face convex, interstriae 1 and 2 moderately inflated from apex to near midpoint of declivity; declivital striae 1-3 approximately equidistant.

Similar species.

Amasa concitata , A. lini , A. tropidacron , A. youlii .

Description

(female). 3.5-3.6 mm long (mean = 3.53 mm; n = 3); 2.33-2.41 × as long as wide. Body dark red-brown. 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, smaller, 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, convex on anterior face, occupying approximately basal 1/4; segment 2 broad, larger than segment 1, corneous; segments 1-3 present on posterior face. Pronotum: 1.02 × 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 six serrations. In lateral view basic, type 0, disc flat, summit at midpoint. Anterior slope strongly shiny with densely spaced, fine asperities, becoming lower and more strongly transverse towards summit, bearing long, fine, semi-recumbent, hair-like setae. Disc shiny, alutaceous, densely finely punctate behind summit, punctures decreasing in density toward base, glabrous. Lateral margins obliquely costate. Base transverse, posterior angles narrowly rounded. Elytra: 1.48 × as long as wide, 1.45 × 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 five diameters of a puncture; interstriae flat, finely punctate, punctures 1/2 size of strial punctures, strongly confused. Declivity truncate, face convex, strongly shiny, smooth, glabrous; three striae present, striae weakly impressed, striae 2 equidistant between striae 1 and 3, strial punctures subshiny, very large and deep, much larger and deeper than on disc, punctures subcontiguous to spaced by one diameter of a puncture; interstriae impunctate, convex, interstriae 1 and 2 moderately inflated from apex to near midpoint of declivity; apical 1/4 of interstriae 1 and 2 with a row of uniseriate rugae. Posterolateral margin forming a circumdeclivital carina; carina setose, setae short, erect hair-like. Legs: procoxae contiguous; prosternal coxal piece flat, inconspicuous. Protibiae distinctly triangular, broadest at apical 1/3; posterior face inflated, coarsely granulate; apical 1/2 of outer margin with six or seven small socketed denticles, their length as long as basal width. Meso- and metatibiae broad, flattened; outer margins evenly rounded with 11 and nine small to minute socketed denticles, respectively; posterior faces unarmed; anterior faces finely granulate.

Etymology.

L. gibbosa = humped. In reference to the rather bulging declivity. A variable adjective.

Distribution.

Thailand.

Host plants.

Unknown.

Figures

Figure 8. Dorsal, lateral and declivital view of Amasa cylindrotomica, 2.1 - 2.4 mm (A, B, I), A. eugeniae paratype, 2.8 - 3.2 mm (C, D, J), A. galeoderma holotype, 3.0 mm (E, F, K), and A. gibbosa holotype, 3.5 - 3.6 mm (G, H, L).