Euwallacea geminus, 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

Euwallacea geminus sp. nov. Fig. 55C, D, J

Type material.

Holotype, female, Vietnam: Dong Nai, Cat Tien N.P., 11.44221, 107.43114, 379 m, 20.ii.2017, VN79, A.I. Cognato, T.A. Hoang, ex 4 cm diameter branch (MSUC). Paratypes, female, as holotype (MSUC, 1; NHMUK, 1; NMNH, 2; VNMN, 2).

Diagnosis.

2.7-2.8 mm long (mean = 2.72 mm; n = 5); 2.33-2.35 × as long as wide. This species is distinguished by the pronotum basic (type 2) when viewed dorsally, anterior margin appearing rounded; elytral bases weakly costate, granulate; declivity rounded; declivital face convex; protibiae outer margins rounded with at least eight socketed denticles, denticles small, their sockets small; declivital surface shiny; declivital interstriae bearing sparse small granules; posterolateral declivital margin carinate and granulate; and elytral bases weakly carinate and granulate.

This species is identical to E. malloti and can only reliably be identified with molecular data. Without molecular data it can be distinguished by its distribution in lowland forests ( E. malloti primarily occurs in submontane forests of the Himalayas) and by the often unique coloration of the elytral striae which are dark brown in mature specimens making the punctures appear very distinctive and clear to see ( E. malloti strial punctures not colored differently from the rest of the elytra). This species is also nearly identical to the E. fornicatus species complex and can be separated by the elytral bases weakly carinate and posterolateral declivital margin costate and granulate.

Similar species.

Euwallacea fornicatus species complex ( E. fornicatior , E. fornicatus , E. kuroshio , E. perbrevis ), E. andamanensis , E. malloti , E. semirudis , E. neptis , E. testudinatus , E. velatus .

Description

(female). 2.7-2.8 mm long (mean = 2.72 mm; n = 5); 2.33-2.35 × as long as wide. Pronotum, head, antennae, and legs light brown, elytra darker, red-brown. Head: epistoma entire, transverse, with a row of hair-like setae. Frons weakly convex to upper level of eyes; surface strongly shiny, median 2/3 smooth, impunctate, lateral 1/3 sparsely and finely punctate, setose; punctures bearing a long, erect hair-like seta. Eyes shallowly emarginate just above antennal insertion, upper part smaller than lower part. Submentum narrow, triangular, slightly impressed. Antennal scape long and slender, as long as club. Pedicel as wide as scape, shorter than funicle. Funicle 4-segmented, segment 1 as long as pedicel. Club longer than wide, flat, type 3; segment 1 corneous, transverse on anterior face, occupying approximately basal 1/4; segment 2 narrow, corneous; segments 1-3 present on posterior face. Pronotum: 0.93 × as long as wide. In dorsal view basic and parallel-sided, sides parallel in basal 3/4, rounded anteriorly; anterior margin without serrations. In lateral view tall, type 2, disc flat, summit at basal 2/5. Anterior slope with densely spaced, broad asperities, becoming lower and more strongly transverse towards summit. Disc strongly shiny with sparse, minute punctures, some longer hair-like setae at margins. Lateral margins obliquely costate. Base transverse, posterior angles acutely rounded. Elytra: 1.24 × as long as wide, 1.3 × as long as pronotum. Scutellum broad, moderately sized, linguiform, shiny, flush with elytra, flat. Elytral base transverse, edge weakly costate and granulate, humeral angles rounded, parallel-sided in basal 3/4, then broadly rounded to apex. Disc convex, shiny, striae not impressed, with large, shallow punctures separated by one diameter of a puncture, glabrous; interstriae flat, impunctate, granulate, granules sparse and widely spaced, each granule with a long, erect seta. Declivity occupying approximately 1/2 of elytra, rounded, declivital face convex, shiny; striae not impressed, strial punctures much larger and deeper than those of disc; interstriae granulate, granules as described for disc, interstriae weakly laterally broadened from declivital summit to apical 1/3 then narrowed to apex. Posterolateral margin carinate, granulate. Legs: procoxae contiguous; prosternal coxal piece tall, pointed. Protibiae broad, semi-circular, with rounded outer margin, broadest at apical 1/3; posterior face smooth; apical 1/2 of outer margin with eight large socketed denticles, their length longer than basal width. Meso- and metatibiae flattened; outer margin evenly rounded with 11 small socketed denticles.

Etymology.

L. geminus = twin. In reference to this species the very close morphology to E. malloti . An adjective.

Distribution.

Vietnam.

Host plants.

Unknown.

Figures

Figure 55. Dorsal, lateral and declivital view of Euwallacea funereus, 3.45 - 3.7 mm (A, B, I), E. geminus holotype, 2.7 - 2.8 mm (C, D, J), E. gravelyi, 4.6 - 5.7 mm (E, F, K), and E. interjectus, 3.5 - 3.9 mm (G, H, L).