Dascillus emarginatus Fu & Jin & Wu 2023, sp. nov.
Creators: name: Fu, Yuting
name: Jin, Zhenyu
name: Wu, Gang
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dascillidae
Dascillus
Dascillus emarginatus

description: Dascillus emarginatus sp. nov.
(Figs 1–2, 4–9, 11–22, 25–26, 29–31)
Type material. Holotype ♁: China, Hubei, Shennongjia, Dongxi Attendance Centre, 1-vi-2020, Ping Wang lgt. Paratypes: 14 ♁, 9 ♀, same data as holotype; 1 ♀, China, Hubei, Shennongjia, Dongxi Attendance Centre, 1-vii-2019, Ping Wang lgt.
Description. Male (Fig. 2). Length 17.2–18.3 mm, width 5.6–5.9 mm. Body 3.0–3.2× longer than broad. Head, antennae, pronotum, scutellar shield and venter black, elytra and legs dark brown. Elytral feebly shiny, glabrous. Head, scutellar shield and pronotal margin setae brown, not forming colour pattern, venter covered by dense brown pubescence.
Head. Antennae reaching middle of elytra. Antennomere 3 about 2.5–2.6× as long as broad, 1.1–1.2× as long as antennomere 4; ultimate antennomere distinctly longer than penultimate. Mandible strongly curved apically; incisor edge with two teeth. Apical palpomere of both maxilla and labium weakly expanded.
Pronotum trapezoidal, 0.5–0.6 × as long as wide, widest just before base; sides sinuate. Lateral carina narrowly explanate with marginal bead, edge smooth with distinct fringe of setae; anterior angles broadly rounded. Disc strongly convex, punctation coarse and dense.
Pterothorax. Scutellar shield 0.9–1.0 × as long as wide, emarginate anteriorly, acute posteriorly (Fig. 4). Elytra moderately convex, together 2.3–2.4 × as long as wide, 4.4–4.5 × as long as pronotum.
Abdominal ventrites (Fig. 7) with glabrous spots on each side; ventrite 5 distinctly projecting apically, 0.4–0.5 × as long as wide, 1.1–1.2 × as long as ventrite 4. Sternite IX (Fig. 25) apically strongly emarginate, at base slightly emarginate, bearing uniformly short setae in middle and apical part. Posterior edge of tergite IX (Fig. 26) also emarginate. Tergite X shorter than tergite IX, apically obtuse.
Aedeagus (Figs 13–22). Phallobase emarginate at base. Parameres longer than phallobase, inner margin upturned apically, slender and narrowly rounded at apex. Apex of ventral lobe obtuse; dorsal lobe also narrowly rounded at apex.
Female (Figs 1, 29). Externally identical to male. Length 18.8–20.3 mm, width 5.6–6.0 mm. Head, antennae, pronotum, scutellar shield and venter dark brown; apex of ventrite 5 obviously emarginate in middle (Figs 6, 8–9). Female spiculum ventrale slightly emarginate apically (Fig. 11), genitalia weakly sclerotised with vagina and bursa copulatrix not clearly separated; bursa copulatrix without sclerites; spermatheca small and not sclerotised. Ovipositor (Fig. 12) short; paraprocts entirely sclerotised, without baculi, slightly shorter than gonocoxites; proctiger absent; gonocoxites entirely sclerotised ventral of paraprocts, triangular and strongly bent, apices prominent, densely setose dorsally, without baculi; gonostyli absent.
Differential diagnosis. At first glance, the new species is very similar to D. attenuatus Jin, Xie & Zhu, 2017, however, it can be easily distinguished from the latter by the combination of the following characters: body length over 17 mm, scutellar shield emarginate anteriorly (Figs 4–5); abdominal ventrites with glabrous spots on each side in both genders (Figs 6–7); ventral lobe of aedeagus broadly rounded apically; sternite IX apically strongly emarginate (Fig. 25); apex of female ventrite 5 obviously emarginate in the middle (Figs 6, 8–9); spiculum ventrale also emarginate at apex (Fig. 11). While in D. attenuatus: body length less than 17 mm, scutellar shield truncate anteriorly (Fig. 3); abdominal ventrites without glabrous spots on each side; apex of ventral lobe distinctly acute in the middle (Fig. 23); sternite IX apically slightly emarginate (Fig. 27); apex of female ventrite 5 broadly rounded; spiculum ventrale truncate at apex (Fig. 10).
Remarks. The shape of the aedeagus is one of the characters frequently used for the identification of Dascillus taxa (Fang et al. 2020, Jin et al., 2013). Recently, Terzani et al. (2017) detected that this character was not constant or specific for the Western Palaearctic dascillids. However, unlike in the widespread European species, we have not found any significant variation in the morphology of aedeagus in a series of eight males of D. emarginatus sp. nov. and three males of D. attenuates. Therefore, we consider the shape of ventral lobe as a constant character with other diagnostic characters to separate the new species from D. attenuatus.
Collection circumstances. Like other species of Dascillus in Shennongjia, males of D. emarginatus sp. nov. were observed feeding on pollen of Castanea sp. (Fagales: Fagaceae) while females suspending on the leaves of nearby unidentified plants in Dongxi Attendance Centre (Figs 29–30).
Etymology. The species name refers to the apex of females’ ventrite 5 obviously emarginate in the middle, distinguished D. emarginatus sp. nov. from all other known Dascillus spp; the name is an adjective.
Distribution. So far known only from the type locality in Shennongjia Nature Reserve, Hubei Province, China (Fig. 31).
description: Published as part of Fu, Yuting, Jin, Zhenyu & Wu, Gang, 2023, A new species of Dascillus Latreille (Coleoptera: Dascillidae) from Hubei, China, pp. 578-584 in Zootaxa 5239 (4) on pages 579-583, DOI: 10.11646/zootaxa.5239.4.8, http://zenodo.org/record/7635377