Eusphaeropeltis chenchaomingi Jiang, Ballerio, Guo & Wang, 2020

Jiang, Ri-Xin, Ballerio, Alberto, Guo, Liang & Wang, Shuo, 2020, Notes on the Chinese fauna of Ceratocanthinae (Coleoptera: Hybosoridae), with description of a new species of Eusphaeropeltis Gestro, 1898, Zootaxa 4851 (1), pp. 180-188 : 181-184

Eusphaeropeltis chenchaomingi Jiang, Ballerio, Guo & Wang , new species (ẄOEỮḪḢm)

( Figs. 1–4 )

Type material. Holotype (deposited in IZAS), ♂, labeled: “ China: Yunnan Province (ỄṄẘ), Nujiang of the Lisu Autonomous Prefecture (ǾừaeṞẂŊaeNj), Gongshan County ( ŃƜH), Dulongjiang Township ( DAE ừ Ø), Maku Village ( Ŗ ẆÙ), 23.VIII.2016, Chao-Ming Chen leg.” . Paratypes (25 specimens): 3 ♂♂, 2 ♀♀, same label data as the holotype (1 ♂, 1 ♀ in LPYC; 1♂, 1♀ in MYNU; 1 ♂ in ABCB); 20 unsexed specimens, labeled: “ China: Yunnan Province (ỄṄẘ), Nujiang of the Lisu Autonomous Prefecture (ǾừaeṞẂŊaeNj), Gongshan County ( ŃƜH), Dulongjiang Township ( DAE ừØ), Qinlangdang Village (ỨOiãÙ), 9–15.V.2014, Yun Ji leg.” (10 specimens in JYCC, 10 specimens will be deposited in China Agricultural University) .

Differential diagnosis. As large Eusphaeropeltis , the new species tends to be mistaken only as E. punctatissimus (Lansberge, 1887) because of its body size and the dense and almost uniform punctation of pronotum and elytra, but the following set of characters tell the differences: a) genal canthus not fused with occipital area of head, b) elytra almost uniformly covered by relatively shallow dense horseshoe-shaped punctures, whereas in E. punctatissimus the elytral punctation is consisted of very dense impressed comma-shaped punctures, c) inferior sutural elytral stria extending to about two thirds the length of elytra, while in E. punctatissimus it extends for about half the length of the elytra, d) pronotum covered by denser impressed punctation varying from simple to horseshoe-shaped and e) absence of flat male protarsomeres II and III, which in E. punctatissimus are expanded and flattened.

Description of the holotype. Male ( Figs. 1 , 2 A–D, H–I, 3A–D), large sized, dorsal surface glabrous, shiny with bronze metallic sheen.

Head wider than long (W/L ratio: 1.12),subpentagonal, clypeus triangular, with apex blunt, genae not protruding outwards, genal canthus almost complete, shortly interrupted before reaching occipital area, dorsal ocular area medium-sized, interocular distance about nine times the maximum width of dorsal ocular area, ventral ocular area very large. Head dorsal surface shiny, disc with sparse small simple punctation, remaining surface with larger and denser impressed comma-shaped punctures mixed with small shallow simple punctures. Anterior clypeal margin and genal canthus with some transverse larger comma-shaped punctures. Interpunctural distance of comma-shaped punctures equal to or shorter than their length.

Antennae ( Fig. 3A ), short, scape securiform, pedicel short and rounded, flagellomeres I to IV similar, wider than long, flagellomere V strongly transverse, about three times as wide as long, antennal club (flagellomeres VI–VIII) covered with dense short yellow hairs.

Pronotum transverse (W/L ratio: 1.75), with maximum width at the end of median third. Dorsal surface covered with dense impressed small punctures, being transversely oriented short comma-shaped on disc and becoming longitudinally oriented short horseshoe-shaped near sides. Anterior angles with punctation similar to the one of pronotal sides. Interpunctural distance being inferior to punctural length.

Scutellum wider than long (W/L ratio = 1.52), sides proximally subparallel and distinctly notched by apical portion of mesepisternum and elytral articular process, then convergent to form a triangle with apex very elongate and acute and sides slightly curved inwards, surface, apart from the smooth base, covered with dense shallow small (about as large as elytral ones) horseshoe-shaped punctures with opening directed backwards, touching each other.

Elytra suboval in shape (dorsal view), convex, longer than wide (W/L ratio: 0.85), humeral callus present; surface shiny and covered, apart from a small discal area where punctures being longitudinally oriented sparser comma-shaped, with dense shallow small (but larger than the pronotal ones) horseshoe-shaped punctures with opening directed backwards and bearing one fine simple puncture just outside opening. Interpunctural distance of horseshoe-shaped punctures equal to or shorter than their length. Sutural stria shallow and visible only on apical third. Inferior sutural stria present and about as log as two-thirds of the elytral length, very deep on median and distal third and shallow on proximal third. striated articular area hardly visible in lateral view, relatively narrow and short; marginal area with some large horseshoe-shaped punctures with opening oriented inwards and some anastomosing shallow lines; elytral articular process well developed, smooth and shiny.

Legs. Outer margin of protibiae ( Figs. 2D, F ) with an irregular number of weak outer teeth ending apically with two stronger outer teeth, apical spur abruptly hooked apically. Mesotibiae ( Fig. 2H ) slightly narrower at apical half, with inner apical spur bent at a right angle. Metatibiae ( Fig. 2I ), sub triangular, strongly expanded apically.

Male genitalia. Aedeagus ( Figs. 3B, C ) with parameres weakly sclerotized; apex of parameres curved and directed forward, symmetrical. Genital segment ( Fig. 3D ) curved with branches apically fused and with short manubrium. Apical margin of sternite VIII ( Fig. 3D ) covered with long setae.

Measurements of the holotype: BL: 6.67 mm; HL: 1.12 mm, HW: 1.75 mm; PL: 1.80 mm, PW: 3.60 mm; EL: 3.75 mm, EW: 3.45 mm.

Measurements of male paratypes: BL: 6.67–6.80 mm; HL: 1.10–1.20 mm, HW: 1.75–1.90 mm; PL: 1.80–1.85 mm, PW: 3.60–3.65 mm; EL: 3.75–3.80 mm, EW: 3.45–3.50 mm.

Female generally similar to male, apical spur of protibiae ( Figs. 2E, G ) straight. Inner apical spur of mesotibiae straight. Spermatheca ( Fig. 3E ) C-shaped. Bursal sclerites ( Fig. 3F ) strongly hooked and sclerotized.

Measurements of female paratypes: BL: 6.50–6.85 mm; HL: 1.00– 1.20 mm, HW: 1.75–1.80 mm; PL: 1.75– 1.80 mm, PW: 3.50–3.60 mm; EL: 3.75–3.85 mm, EW: 3.40–3.50 mm.

Etymology. Noun in the genitive case. This species is named in honor of Mr. Chao-Ming Chen, who collected the holotype of the new species and donated it to us for study.

Distribution and habitat. China: Yunnan Province. The type locality is characterized by the presence of a moist broadleaf evergreen primary forest. The area falls within the Northern Indochina subtropical forests ecoregion ( Wikramanayake 2002), a transition between the tropical forests of Indochina and the subtropical and temperate forests of China.

Biology. The majority of the adults of the new species were collected in rotten wood (the presence of termites inside the logs was not detected), some specimens were collected during the day while flying at the border between the forest and the village ( Figs. 4A, B ).

Remarks. The species herein described is the Eusphaeropeltis sp. illustrated by Ballerio & Grebennikov (2016) in fig. 1B. The male and female genitalia of Eusphaeropeltis which are here illustrated for the first time for the genus are very peculiar compared to the genitalia of other Ceratocanthinae . The aedeagus has very weakly sclerotized parameres. Female genitalia have bursal sclerites, as already noted by Ballerio (2000), a character shared with few other genera of Ceratocanthinae . In Eusphaeropeltis preliminary observations seem to suggest that the shape of the bursal sclerites can be a species-level diagnostic character as already happens in the genus Pterorthochaetes (e.g. Ballerio & Grebennikov 2016). A sexually dimorphic character found in many Eusphaeropeltis species are the flattened and expanded tarsomeres II and III ( Ballerio 2006), with the inferior surface covered by dense setation. Probably this morphological feature, unique within Ceratocantinae, plays a role during mating. This character was not observed in E. chenchaomingi new species.

Figures

FIGURE 1. Dorsal habitus of Eusphaeropeltis chenchaomingi Jiang, Ballerio, Guo & Wang, new species, holotype, male.

FIGURES 2A–I. Diagnostic characters of Eusphaeropeltis chenchaomingi Jiang, Ballerio, Guo & Wang, new species, A, male, ventral view; B, male, lateral view; C, male, dorsal view; D, protibia of male; E, protibia of female; F, apex of male protibia; G, apex of female protibia; H, mesotibia of male; I, metatibia of male.

FIGURES 3A–F. Diagnostic characters of Eusphaeropeltis chenchaomingi Jiang, Ballerio, Guo & Wang, new species, A, antenna; B, aedeagus, ventral view; C, aedeagus, lateral view; D, genital segment of male; E, spermatheca; F, bursal sclerites.

FIGURES 4A–F. Habitat of Eusphaeropeltis chenchaomingi Jiang, Ballerio, Guo & Wang, new species, A, B, general environment of Qinlangdang village (Yunnan, China); C–F, living adult on foliage, at the daytime. All figs were taken by Mr. Yun Ji (Beijing, China), in 9–15.V.2014.