Pseudocsikia chanjuan, Qiu & Kundrata, 2022

Qiu, Lu & Kundrata, Robin, 2022, Descriptions of two new flightless species of Pseudocsikia Schimmel & Platia (Coleoptera, Elateridae, Dimini) from Taiwan Island, China, with a definition of the formosana species-group, ZooKeys 1103, pp. 123-138 : 123

Pseudocsikia chanjuan sp. nov.

Figs 1B , 4A-H , 5G-L

Type material.

Holotype, male, "2017.IX.16, 台湾台东县金峰乡太麻里山, 1300 m, 周文一” [Mount Taimalishan, Taitung County, Taiwan, 1300 m, 16.IX.2017, Wen-I Chou leg.], " Pseudocsikia chanjuan sp. nov. 婵娟伪斯叩甲 HOLOTYPE des. Qiu et Kundrata 2022" (MYNU).

Diagnosis.

Pronotum and elytra almost unicolored brown, but with paler apices of elytra and lateral margins of pronotum (in dry specimen condition), legs yellow (Fig. 1B ). Antennomere II shorter than the length of antennomere III. Pronotum (Fig. 4A ) with dense punctures (intervals usually subequal to 2-4 puncture diameters). Anterior angle of pronotum with the protrusion outward at outer angle. Posterior angle straight. Metaventrite densely punctate, intervals between punctures on average subequal to 2-3 puncture diameters. Metacoxal plate (Fig. 4G ) short internally, surface densely covered with punctures. Tergite IX (Fig. 5H ) suboval, with two robust lobes. Median lobe with small lateral pointed process near midlength, apical portion rounded and enlarged. Paramere with rounded apex and small process subapically. Phallobase subtrapezoidal, with slightly pointed basal angles (Fig. 5J ).

Comparison.

This species can be distinguished from P. formosana and P. choui sp. nov. by the denser punctures of pronotum and larger body size (6.3 mm versus 4.0-5.9 mm). This new species can be further distinguished from P. choui sp. nov. by the more outwardly protruded anterior angles of pronotum, and the larger and straight posterior angle of pronotum. The shape of aedeagus also differs from these. The median lobe of P. chanjuan sp. nov. has a slightly enlarged and rounded apex and two small acute processes laterally near midlength, its paramere is rounded at apex but with small process subapically, and the phallobase is less rounded basally than those of the other two species.

Description

(male holotype). Body smooth, surface covered with curved, semi-erect, and moderately long pubescence. Body length 6.3 mm; width 2.3 mm; antenna length 3.3 mm; pronotum length 1.7 mm, width 2.1 mm (measured at hind angles), elytra length 3.7 mm.

Body generally brown, pubescence yellow (Fig. 1B ). Head (including antennae and mouthparts), pronotum, elytra (except apical portions), underside (except last two sternites and lateral portion of abdomen) brown. Pronotum with paler lateral margins (in dry condition). Legs, apical portion of elytra, the last two sternites, and lateral portion of abdomen yellowish brown.

Head including eyes 0.5 times as wide as pronotum. Supra-antennal carinae short, directed mesad and fading medially so that median portion of frontoclypeus is not formed by sharp carina; frontoclypeus overhanging base of labrum in lateral view. Head surface with intervals between punctures mostly equal 1-2 puncture diameters. Maxillary palpus with palpomere III longer than wide. Antenna (Fig. 4E ) simple, surpassing hind angle of pronotum about 1½ antennomeres; scape robust and longest, antennomere II shortest, antennomere III longer than antennomere II, antennomeres IV-X subequal in length, ratio of antennomeres II-IV and XI = 1: 1.1: 1.3: 1.5, ultimate antennomere tapered apically, apex pointed.

Pronotum (Fig. 4A ) large, subquadrate, wider than long (measured at midlines), widest near middle. In lateral view, pronotum convex. Anterior angles (Fig. 4C ) of pronotum protruded, protrusion of anterior angle subquadrate, inner angle protruded almost same degree as outer angle; prostrusion with deep, narrow and curved gap. Lateral margins of pronotum roundly arched medially, sides near middle more or less evenly narrowing anterad and posterad in similar degree, posterior angle (Fig. 4F ) straight, less divergent, pointing straightly toward elytra, apex blunt, inner margin with small protrusion. Disc of pronotum densely covered with small, deep punctures; intervals between punctures on average subequal to 2-4 puncture diameters; interstices smooth. Pubescence directed outwards; basal portion directed forwards.

Hypomeron (Fig. 4B ) more densely punctate than pronotum, punctures moderate and deep, intervals between punctures on average subequal to 1-2 puncture diameters, apex of hypomeron strongly protruded, margin wrinkled. Pronotosternal sutures nearly straight, anterior excavation deep and narrow; long carination paralleled with suture from base of hypomeron and reaching anterior protrusion of hypomeron, forming elongate U-shaped carination anteriorly; end of the carination extending backwards, with a straight, elongate pit partly enclosed by curving hook of carination (Fig. 4D ). Prosternum (Fig. 4B ) including prosternal process 2.2 times as long as wide; chin piece with dense and large punctures, intervals between punctures on average subequal to half to one puncture diameter; punctures in remaining area slightly sparser and smaller, intervals between punctures on average subequal to 1-2 puncture diameters. Prosternal process (Fig. 4H ) ventrally straight in lateral view, ventroapically with notch; small process in notch acutely enlarged dorsoapically.

Scutellar shield (Fig. 4A, F ) suboval, about 1.2 times as wide as long; anterior margin rounded, posterior margin slightly pointed.

Mesoventrite (Fig. 4B ) with procoxal rests. Mesoventral process elevated, hind margin narrow. Mesanepisternum with large, curved lateral extensions of procoxal rests. Metaventrite medially with dense punctures, intervals between punctures on average subequal to 2-3 puncture diameters. Anterior portion of discrimen with needle-like groove, occupying half-length of metaventrite. Metacoxal plate enlarged inward, strongly reduced outward (Fig. 4G ), surface densely punctate.

Elytra (Fig. 1B ) elongate, together 1.7 times as long as wide, widest at 1/3 of their length from base. Humeri (Fig. 4A, F ) elevated, sides from humeri roundly widened to 1/3 of elytral length, then gradually narrowed towards apices; apices slightly independently rounded. Elytral striae shallow, formed by lines of small punctures, intervals between punctures in stria on average subequal to 2-4 puncture diameters. Interstriae flat, smooth, with some micropunctures. Hind wings absent. Abdomen with ventrites more densely punctate than pronotum, intervals between punctures on average subequal to one puncture diameter; pubescence directed backwards. Apical ventrite with rounded apex. Tergite VIII (Fig. 5I ) subtriangular, 1.7 times as long as wide, distal margin pointed medially, apically covered with sparse pubescence, basal angles rounded. Sternite VIII (Fig. 5I ) with two dark-colored lobes, shape as Fig. 5I with long setae, remaining portion membranous. Tergite IX (Fig. 5H ) semi-oval, 1.2 times as long as wide, medially deeply and widely emarginate; two lobes robust, lateral sides with long setae; tergite X (Fig. 5H ) membranous, exceeded apices of lobes of tergite IX. Sternite IX (Fig. 5G ) relatively narrow, 2.66 times as long as wide, apically truncate and setose.

Aedeagus (Fig. 5J-L ) with robust median lobe, 1.7 times as long as one paramere; distal half of median lobe gradually narrowed to a rounded point, with one small pointed processes on each lateral side near midlength, apical portion enlarged, apex bluntly rounded; median lobe with long, needle-like ventral sclerite. Paramere stout, slightly exceeding half of median lobe; apex rounded, with small process subapically. Phallobase trapezoidal, margins thickened, medially with longitudinal thickened line, basal angles angled.

Female. Unknown.

Immature stages.

Unknown.

Distribution.

China: Taiwan (Taitung).

Etymology.

The specific epithet Chanjuan is derived from the Chinese 婵娟 [ chán juān], which means “beauty”.

Figures

Figure 1. Habitus of Pseudocsikia spp. A Pseudocsikia choui sp. nov., male holotype, dorsal view B Pseudocsikia chanjuan sp. nov., male holotype, dorsal view. Scale bar: 1.0 mm.

Figure 4. Characters of Pseudocsikia chanjuan sp. nov., male, holotype A pronorum, dorsal view B pro- and mesothorax, ventral view C anterior protrusion of pronotum, dorsal view D anterior protrusion of hypomeron, ventral view E antenna F posterior angle of pronotum, dorsal view G metacoxal plate, ventral view H prosternal process, lateral view. Scale bars: 0.5 mm (A, B, E, F); 0.2 mm (C, D, G, H).

Figure 5. Characters of Pseudocsikia spp. A-F Pseudocsikia choui sp. nov., male holotype G-L Pseudocsikia chanjuan sp. nov., male, holotype A, G abdominal sternite IX, dorsal view B, H abdominal tergites IX-X, dorsal view C, I abdominal sternite VIII and tergite VIII, ventral view D, J aedeagus, ventral view E, K aedeagus, lateral view F, L aedeagus, dorsal view. Scale bar: 0.2 mm.