Pseudocsikia douglasi Hoffmannova and Qiu, 2023

Hoffmannova, Johana & Qiu, Lu, 2023, Description of a New Species of Pseudocsikia Schimmel and Platia, 1991 (Coleoptera: Elateridae: Dimini) from Taiwan Island, The Coleopterists Bulletin 77 (2), pp. 265-271 : 266-269

Pseudocsikia douglasi Hoffmannova and Qiu , new species zoobank.org/ urn:lsid:zoobank.org:act:EFE16CCE-CC75-4B08-8522-0FBBFD27BA37 ( Figs. 1–3 )

Type Material. Holotype, male, “ TAIWAN, Taidong [Taitung], / LiJia road [ Lichia Forest Road in Beinan Township ], 22.8062 [N 22.8062] / 121.0310 [E 121.0310], 1015m, / 19. viii. 2013 sift TW09, / V. Grebennikov” ( CNCI).

Type Locality. China: Taiwan (Taitung County, Beinan Township, Lichia Forest Road, 1015 m) .

Diagnosis. Body ( Fig. 1A ) yellowish brown to reddish brown, central portion of pronotum, elytra and abdomen darker, pubescence yellowish. Antennomere III 1.40 times as long as antennomere II. Pronotum ( Fig. 2A ) convex in lateral view, with sparse punctures (intervals usually subequal to two to four puncture diameters). Anterior angle of pronotum protruding. Posterior angles slightly divergent. Metacoxal plate ( Fig. 1C ) enlarged inward, sparsely punctate. Tergite IX ( Fig. 3A ) subtriangu- lar, with two narrow lobes. Aedeagus ( Figs. 3C–E ) slender, narrow, about 3.50 times as long as wide (other species of this genus from Taiwan Island have the aedeagus more robust and relatively wider); with median lobe with acute lateral projections near midlength, narrowed to apex, apex simple and moderately sharp. Paramere ( Figs. 3C, E ) with apex directed outward. Phallobase ( Figs. 3C, E ) subquadrate, with basal angles rounded.

Comparison. This species superficially resembles P. fomosana , P. chanjuan and P. choui by the pale coloration of its pronotum and elytral sides and by the sparse punctures of the pronotum. It can be easily distinguished from P. fomosana by the larger body length (5.30 mm; 4.00 mm in P. formosana ), and darker coloration of the pronotum and elytra medially. It can be distinguished from P. chanjuan and P. choui by the smaller body length (5.30 mm; 5.90–6.30 mm in P. choui and P. chanjuan ). The shape of the aedeagus is also different from these two species. Pseudocsikia choui and P. chanjuan have more robust and relatively wider aedeagi, which are about 2.50 times as long as wide (aedeagus slender, narrow, about 3.50 times as long as wide in P. douglasi ); the apex of the median lobe in P. chanjuan is bluntly rounded and has an enlarged apical portion, and in P. choui the apex is blunt, laterally with small acute projections (apex simple, moderately sharp in P. douglasi ); the apex of the paramere in P. chanjuan is rounded, with a small process subapically, and in P. choui it is pointed (apex rounded in P. douglasi ); and the phallobase in P. chanjuan is trapezoidal, while in P. choui and P. douglasi it is subquadrate.

Description (Male Holotype). Body ( Figs. 1A–C ) surface smooth, covered with curved, semierect, and moderately long pubescence. Body length 5.30 mm; width 2.00 mm; antenna length 2.80 mm; pronotum length 1.35 mm (measured at midline), pronotum width 1.85 mm (measured at middle, which is also the widest point), elytra length 3.30 mm. Body yellowish brown to reddish brown, with antennae and palpi generally lighter than head; central portion of pronotum darker, dark reddish brown; scutellar shield with edges darker, dark brown to black; elytra dark brown to black centrally and gradually lighter towards humeral part; legs yellow; pubescence yellowish.

Head ( Fig. 2C ) including eyes 0.50 times as wide as pronotum. Supra-antennal carinae short, directed mesad and fading medially so that median portion of frons is not formed by sharp carina; frons overhanging base of labrum in lateral view. Head surface sparsely punctate; punctures small, intervals between punctures on average subequal to one to three puncture diameters. Maxillary palpus with last palpomere approximately 2.30 times as long as wide, axe shaped. Antenna ( Fig. 1D ) slightly surpassing posterior angles of pronotum; scape quite robust and longest, pedicel shortest, approximately 1.80 times as long as wide, antennomere III approximately 2.20 times as long as wide and 1.40 times as long as pedicel, antennomeres III–X subequal in length, terminal antennomere approximately 1.20 times as long as antennomere X; terminal antennomere slightly obliquely truncate, with apex rounded [apical antennomere of right antenna missing].

Pronotum ( Fig. 2A ) 1.40 times as wide as long, widest near middle; convex in lateral view.Anterior angles of pronotum protruding ( Fig. 2E ); protrusion of anterior angle subquadrate, posterior part of protrusion with deep, crescent-shaped pit. Lateral margins of pronotum arched medially, sides near middle narrowing anteriad and posteriad; posterior angles ( Fig. 2D ) long, slightly divergent, apical portion of posterior angle slightly enlarged, then narrowed, apex blunt. Disc of pronotum sparsely covered with small, shallow punctures; intervals between punctures usually subequal to two to four puncture diameters; interstices smooth. Pubescence mostly directed outwards, in basal portion of pronotum mostly directed anteriorly. Hypomeron ( Fig. 2B ) with punctures small and shallow, intervals between punctures usually subequal to two to four puncture diameters. Pronotosternal sutures ( Fig. 2B ) subpar- allel anteriorly, slightly sinuate, anterior excavation distinct, wide. Prosternum ( Fig. 2B ) including prosternal process about 2.20 times as long as wide; chin piece with large, dense punctures, intervals between punctures slightly less than one puncture diameter; punctures in remaining area sparser and smaller, intervals between punctures usually two to three puncture diameters. Prosternal process ( Fig. 2B ) with ventral surface horizontal in lateral view, with elongate notch ventroapically. Scutellar shield ( Fig. 2D ) suboval, about as long as wide; anterior margin widely rounded, posterior margin rounded. Mesoventrite ( Fig. 2B ) with deep procoxal rests; mesoventral cavity well defined, deep. Metaventrite ( Fig. 1C ) about 1.60 times as wide as long; puncta- tion similar to that on prosternum. Metacoxal plate ( Fig. 1C ) enlarged inward, narrowed laterad, poste- riorly narrowly emarginate, surface with sparse punctures. Elytra ( Fig. 1A ) elongate, together 1.65 times as long as wide, widest at one-third of their length from base. Humeri ( Figs. 2A, D ) elevated. Sides from humeri arcuately widened to one-third of elytral length in dorsal view, then gradually narrowed towards apices; apices slightly independently rounded. Elytral striae shallow, formed by lines of punctures smaller in inner striae and larger in outer striae, intervals between punctures in striae usually subequal to one to three puncture diameters. Interstriae flat, smooth, with small, sparse micro- punctures. Hind wings absent.

Abdomen ( Fig. 1C ) with ventrites more densely punctate than pronotum, intervals between punctures on average subequal to one to two puncture diameters; pubescence directed backwards. Apical ventrite with almost rounded apex. Abdominal tergite IX ( Fig. 3A ) 1.20 times as long as wide, anteriorly deeply emarginate medially; lateral sides with long setae; tergite X ( Fig. 3A ) minute, elongate, partly membranous. Abdominal sternite IX ( Fig. 3B ) relatively narrow, 3.35 times as long as wide, apically narrowly rounded and setose; sternite X ( Fig. 3B ) minute, elongate, partly membranous. Aedeagus ( Figs. 3C–E ) about 3.50 times as long as wide; median lobe robust, medially 1.70 times as long as paramere; distal half of median lobe ar- row-shaped, gradually narrowed toward apex, apex simple, moderately sharp; long needle-like sclerite present on ventral side of median lobe. Paramere stout, almost reaching half length of median lobe; apex rounded, directed outward. Phallobase subquadrate, slightly longer than wide, margins thickened, medially with longitudinal thickened line, basal angles slightly constricted, rounded.

Female. Unknown.

Immature Stages. Unknown.

Bionomics. This species was collected by sifting the forest floor.

Distribution. China: Taiwan (Taitung).

Etymology. The specific epithet is a patronym in honor of Dr. Hume B. Douglas (CNCI).

KEY TO SPECIES OF PSEUDOCSIKIA FORMOSANA - SPECIES GROUP (modified from Qiu and Kundrata 2022a)

1. Pronotum with anterior angles widely and strongly protruded with lateral concavity, with pits at posterior part of protrusion in both dorsal and ventral views ..................................... ..................... 2 ( P. formosana -species group)

1′. Pronotum with anterior angles not or simply, gradually and narrowly protruded, without pits if protruded..... other species of Pseudocsikia

2. Aedeagus slender, narrow, about 3.50 times as long as wide; median lobe of aedeagus with apex simple, moderately sharp ( Fig. 3C ) ...... P.douglasi Hoffmannova and Qiu , new species

2′. Aedeagus more robust and relatively wider, up to about 2.50 times as long as wide; median lobe of aedeagus with apex not simple and moderately sharp, variously shaped ............ 3

3. Pronotum relatively densely punctate, with intervals between punctures usually two to four puncture diameters (Qiu and Kundrata 2022a: fig. 4A); median lobe of aedeagus with one small pointed process on each lateral side near midlength, apex simply enlarged, widely rounded, without any acute projections (Qiu and Kundrata 2022a: fig. 5J)......................... ................... P. chanjuan Qiu and Kundrata

3′. Pronotum relatively sparsely punctate, with intervals between punctures usually three to six puncture diameters (Qiu and Kundrata 2022a: fig. 3A); median lobe of aedeagus with one large acute lateral projection on each lateral side near midlength, apically or subapically with lateral acute projection ............... 4

4. Median lobe of aedeagus with narrowed apical portion, apex additionally with blunt protrusion which with small acute lateral projections; apex of paramere acute and pointing outwards (Qiu and Kundrata 2022a: fig. 5D) ......................... P. choui Qiu and Kundrata

4′. Median lobe of aedeagus with large rectangu- lar apical portion, apex blunt, without protrusion, but with two large acute projections subapically; apex of paramere rounded ( Ôhira 1972: fig. 3)................ P. formosana (Ôhira)

Figures

Fig. 1. Pseudocsikia douglasi, new species, holotype, male. A–C) Habitus, dorsal, lateral and ventral view, respec- tively, D) Antenna. Scale bars = 2.5 mm (A–C), 1.5 mm (D).

Fig. 2. Pseudocsikia douglasi, new species, holotype, male. A) Head and pronotum, dorsal view, B) Prothorax, ventral view, C) Head, frontal view, D) Posterior angles of pronotum, basal portion of elytra and scutellar shield, dorsal view, E) Head and anterior portion of pronotum, dorsal view. Scale bars = 1.0 mm (A–C), 0.5 mm (D, E).

Fig. 3. Pseudocsikia douglasi, new species, holotype, male. A) Genital capsule, dorsal view, B) Genital capsule, ventral view, C–E) Aedeagus, dorsal, lateral and ventral view, respectively. Scale bars = 0.5 mm (A–E).