Cyclorhipidion obesulum, 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

Cyclorhipidion obesulum sp. nov. Fig. 43C, D, J

Type material.

Holotype, female, China: S. Yunnan, Xishuangbanna, 23 km NW Jinghong, vic. Na Ban village (NNNR), 22°10'N, 100°39'E, 700-1000 m, v-vii.2009, L. Meng (NKME).

Diagnosis.

2.1 mm long (n = 1); 2.45 × as long as wide. This species is distinguished by the elytral disc convex; declivity rounded; and elytral apex bearing a single, strong triangular spine at the end of interstriae 2.

Similar species.

Cyclorhipidion armiger , C. miyazakiense , C. xyloteroides .

Description

(female). 2.1 mm long (n = 1); 2.45 × as long as wide. Appearing bicolored: body, antennae, legs, elytral base light brown, remainder of declivity darker brown. Head: epistoma entire, transverse, with a row of hair-like setae. Frons weakly convex to upper level of eyes; surface subshiny, impunctate, alutaceous, finely rugose. Eyes deeply emarginate just above antennal insertion, upper part smaller than lower part. Submentum narrow, 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 3; segment 1 corneous, transverse on anterior face, occupying approximately basal 1/3; segment 2 narrow, corneous; segments 1 and 2 present on posterior face. Pronotum: 1.17 × as long as wide. In dorsal view long and rounded frontally, type 7, sides parallel in basal 1/2, rounded anteriorly; anterior margin without serrations. In lateral view elongate with disc much longer than anterior slope, type 7, disc flat, summit at apical 2/5. Anterior slope shagreened, with densely spaced, fine, narrow asperities, becoming lower and more strongly transverse towards summit, bearing long, fine, semi-recumbent, hair-like setae. Disc shiny, densely, finely punctate, finely setose, setae short, erect, hair-like. Lateral margins obliquely costate. Base transverse, posterior angles broadly rounded. Elytra: 1.2 × as long as wide, 1.03 × as long as pronotum. Scutellum large, broad, linguiform, flush with elytra, flat, shiny. Elytral base transverse, edge oblique, humeral angles rounded, parallel-sided in basal 2/3, then broadly rounded to apex. Disc convex, shiny, striae and interstriae densely setose, setae very short, semi-recumbent, hair-like, striae and interstriae strongly confused, indistinguishable; striae and interstriae not impressed, minutely punctate, punctures strongly confused, separated by one diameter of a puncture. Declivity occupying 1/3 of elytra, declivital slope gradual, rounded, shagreened, separation between the smooth, shiny disc and shagreened declivity gradual, not sharply distinct; three striae present, striae 2 equidistant between 1 and 3, striae not impressed, punctures small, shallow, distinct, spaced by one diameter of a puncture, shagreened, larger than on disc; interstriae feebly convex, setose, setae dense, long, semi-erect hair-like, apically increasing in length and thickness, each interstriae with two rows; interstriae 1 laterally broadened from declivital summit to midpoint then narrowed to apex, minutely punctate, punctures strongly confused, interstriae 1 with two large tubercles in median area (variable placement on each elytron), interstriae 2 unarmed, interstriae 3 with two equally spaced tubercles on apical 1/2; apex bearing a single, strong triangular spine at apex of interstriae 2. Posterolateral margin round, granulate. Legs: procoxae contiguous; prosternal coxal piece flat and inconspicuous. Protibiae semi-circular with evenly rounded outer edge, broadest at apical 1/3; posterior face smooth; apical 1/3 of outer margin with six moderate socketed denticles, their length approximately as long as basal width. Meso- and metatibiae broad, flattened; outer margin evenly rounded with eight moderate socketed denticles.

Etymology.

L. obesus = stout, plump; - ulum = diminutive suffix. An adjective.

Distribution.

China (Yunnan).

Host plants.

Unknown.

Figures

Figure 43. Dorsal, lateral and declivital view of Cyclorhipidion neocavipenne holotype, 2.5 mm (A, B, I), C. obesulum holotype, 2.1 mm (C, D, J), C. ohnoi holotype, 4.1 - 4.2 mm (E, F, K), and C. pelliculosum, 3.2 - 3.5 mm (G, H, L).