Amasa youlii, 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 youlii sp. nov. Fig. 10E, F, I

Type material.

Holotype, female, China: Fujian, Fuzhou, Qishan, 31.iii.2018, Y. Li, ex 5 cm diameter twig, possibly Fagaceae (IZAS). Paratypes, female, as holotype (MSUC, 1; NMNH, 1)

Diagnosis.

2.9-3.0 mm long (mean = 2.93 mm; n = 3); 2.42-2.5 × as long as wide. This species is distinguished by the pronotum appearing basic (type 2) when viewed dorsally, anterior margin serrate; declivital surface smooth, moderately shiny; small size; declivital interstriae setose, setae recumbent; declivital face flattened; and interstriae 1 weakly inflated from apex to near midpoint of declivity; and declivital striae 2 medially displaced, not appearing equidistant between striae 1 and 3.

Similar species.

Amasa concitata , A. gibbosa , A. lini , A. tropidacron .

Description

(female). 2.9-3.0 mm long (mean = 2.93 mm; n = 3); 2.42-2.5 × as long as wide. Body bicolored: pronotal disc, head, legs, and antennae reddish, anterior slope of pronotum, elytra, and abdomen 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 deeply emarginate just above antennal insertion, upper part smaller than lower part. Submentum triangular, deeply impressed. Antennal scape regularly thick, longer than 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 basal 1/4; segment 2 narrow, larger than segment 1, corneous; segments 1-3 present on posterior face. Pronotum: 0.88 × 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 4-6 serrations. In lateral view basic, type 0, disc flat, summit at midpoint. Anterior slope strongly shagreened with densely spaced, short fine asperities, becoming lower and more strongly transverse towards summit, bearing long, fine, semi-recumbent hair-like setae. Disc shiny, alutaceous, densely minutely punctate, glabrous. Lateral margins obliquely costate. Base transverse, posterior angles narrowly rounded. Elytra: 1.45 × as long as wide, 1.65 × 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 1-4 diameters of a puncture; interstriae flat, finely punctate, punctures 1/2 size of strial punctures, strongly confused. Declivity truncate, face flattened, moderately shiny, smooth, setose; three striae present, striae weakly impressed, striae 2 medially displaced near striae 1, strial punctures shiny, moderately large, moderately deep, much larger than on disc, punctures subcontiguous to spaced by three diameters of a puncture; interstriae impunctate, convex, interstriae 1 moderately inflated from apex to above declivital midpoint, interstriae 1 uniseriate granulate, 2-4 multiseriate granulate, granules strongly confused; apical 1/2 of interstriae 1 carinate to just before apex, becoming flattened, apical 1/4 of interstriae 2 costate, nearly carinate, with a row of rugae. Posterolateral margin forming a circumdeclivital carina; carina setose, setae short, erect hair-like. Legs: procoxae contiguous, prosternal coxal piece flat, inconspicuous. 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 and nine small socketed denticles, respectively, posterior faces unarmed; anterior faces finely granulate.

Etymology.

Named after the collector Dr. You Li for his generous contributions to this project. Noun in genitive, invariable.

Distribution.

China (Fujian).

Host plants.

Unknown but potentially collected from Fagaceae .

Figures

Figure 10. Dorsal, lateral and declivital view of Amasa tropidacron holotype, 2.5 - 2.8 mm (A, B, G), A. versicolor, 2.5 - 2.6 mm (C, D, H), and A. youlii holotype, 2.9 - 3.0 mm (E, F, I).