Cyclotoma simianshanensis, Chang & Ren, 2023

Chang, Ling-Xiao & Ren, Guo-Dong, 2023, New and little-known species of the genus Cyclotoma from China (Coleoptera: Endomychidae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1), pp. 177-185 : 178-184

Cyclotoma simianshanensis sp. nov.

( Figs 1D–F , 2B , 3B , 4B , 6 )

Type material. HOLOTYPE: ♁, CHINA: CHONGQING: ‘China. Chongqing, Jiangjin, Simianshan , 1100 m, 2011.VII.27, leg. Hao Xu & Jian-Yue Qiu’ ( MYNU) . PARATYPES: CHINA: CHONGQING: 3 ♁♁ 2 ♀♀, same collecting data as holotype ( NNHMC); 4 ♁♁, ditto except ‘Simianshan, Dawopu’ ( NNHMC).

Diagnosis. Cyclotoma simianshanensis sp. nov. resembles C. formosana , C. indiana , C. parvimaculata , and C. yingjiangensis sp. nov. in the four spots on pronotum, seven spots on each elytron. But it can be differentiated from C. formosana in the femora uniformly black (vs. femora near apical 1/2 black); from C. indiana in antennomere 4 distinctly shorter than antennomere 3 and slightly longer than 5 (vs. antennomere 4 elongate, hardly shorter than antennomere 3 and distinctly longer than 5); from C. parvimaculata in the three lateral elytral spots visible dorsally (vs. barely visible dorsally); abdominal ventrite 1 with lines bordering edge of coxal cavity simple (vs. lines bordering edge extending posteriorly); from C. yingjiangensis sp. nov. in the antenna uniformly brownish-black (vs. antennomeres 1–9 yellowish-brown, club brownish-black); ventrite 1 with black spots (vs. ventrites 1–3 with black spots).

Description. Male ( Figs 1D–E , 2B ). Length 5.9–6.8 mm; body 1.2–1.3 times longer than wide; height 3.1–3.7 mm, about 0.5 times as high as long, smooth, strongly shiny. Dorsal surfaces yellowish-brown with scutellum, suture, spots on pronotum and on elytra black; leg and antenna dark brown; ventral surfaces yellowish-brown.

Antenna 11-segmented with scape long and stout, 3.0 times longer than pedicel; antennomere 2 near quadrate, antennomere 3 longer than antennomere 4; antennomere 4 longer than antennomere 5; antennomere 5 longer than wide; antennomeres 6–8 transverse and subequal in length; club almost as long as remaining antennomeres combined. Maxilla with terminal palpomere longer than wide, tapering apically.

Pronotum 1.1–1.4 mm long, 2.7–3.3 mm wide; about 0.4–0.6 times as long as wide; with four similar, circular black spots; two smaller lateral spots and two larger spots in middle; anterior and lateral edges very narrowly bordered; disc weakly convex. Pronotal surface polished between punctures, punctation rather dense and moderately coarse. Prosternal process widely separates front coxae, about 1.2 times as wide as longest coxal diameter and narrower than intercoxal process of mesoventrite, widening behind front coxae; sides weakly curved, rounded at apex. Elytra 5.2–6.0 mm long, 4.8–5.7 mm wide; 1.1 times as long as wide; 4.0–4.7 times longer than pronotum, 1.7–1.8 times wider than pronotum; sides abruptly converging from about half-length towards apex; each elytron with seven black spots of different size and shape (one humeral, three near lateral margin, three sutural); sutural spots with inner margin not touching elytral suture; three lateral spots with outer margin distant from lateral margin of elytra. Humeri moderately prominent; elytral surface polished between punctures, punctation as large as pronotal ones, rather dense and moderately coarse.

Ventrite 1 with lines bordering edge of coxal cavity simple ( Fig. 3B ); two transverse black spots in middle; ventrite 5 nearly truncate at apex. Aedeagus ( Fig. 4B ) long, thin, strongly curved, curled at its base; tegmen located in apical 1/3 with large, submembranous, tegminal plate with length reaching nearly basal 1/6 of aedeagus.

Female. Habitus ( Fig. 1F ) similar to males. Elytra with sides gently and widely converging posteriad in apical 1/3.

Etymology. The name refers to the type locality, Simianshan Mt., Chongqing, China; adjective.

Biology and ecology. The adults were found during the day gathered on fungi and lichens growing on the surface of a rock ( Figs 6B, C ). The adults have the habit of feigning death or thanatosis ( Fig. 6D ). As many other genera of handsome fungus beetles, they display reflex bleeding from the tibiofemoral joints when a small amount of milky white liquid can be seen overflowing ( Fig. 6D ).

Distribution. China: Chongqing.

Figures

Fig. 1. Habitus of Cyclotoma spp. nov. A–B – C. nigrithorax sp. nov., male (A ‒ dorsal view; B ‒ lateral view). C – C. nigrithorax sp. nov., female, dorsal view. D–E – C. simianshanensis sp. nov., male (D ‒ dorsal view; E ‒ lateral view). F – C. simianshanensis sp. nov., female (F ‒ dorsal view). G–H – C. yingjiangensis sp. nov., male (G ‒ dorsal view; H ‒ lateral view). I – C. yingjiangensis sp. nov., female (I ‒ dorsal view). Scale bars: 1.0 mm.

Fig. 2. Ventral view of males of Cyclotoma spp. nov. A – C. nigrithorax sp. nov., B – C. simianshanensis sp. nov., C – C. yingjiangensis sp. nov. Scale bars: 1.0 mm.

Fig. 3. Abdomen of Cyclotoma spp. nov. (ventral view). A – C. nigrithorax sp. nov., B – C. simianshanensis sp. nov., C – C. yingjiangensis sp. nov. Scale bars: 1.0 mm.

Fig. 4. Aedeagus of Cyclotoma spp. nov. (lateral view). A – C. nigrithorax sp. nov., B – C. simianshanensis sp. nov., C – C. yingjiangensis sp. nov. Scale bars: 0.5 mm.

Fig. 6. Habitats and habitus of C. simianshanensis sp. nov. A – habitats of collecting site in Chongqing, China. B–C – adults of C. simianshanensis sp. nov. gather on the fungus and lichen growing on rock. D – adults of C. simianshanensis sp. nov. are feigning death. (Photos by Hao Xu).