Giraffaphaenops brevicephalus, Ma & Huang & Tian, 2020

Ma, Zijun, Huang, Sunbin & Tian, Mingyi, 2020, Two new species of cavernicolous trechines from central Guizhou and northwestern Guangxi, China (Coleoptera: Carabidae: Trechinae), Zootaxa 4861 (4), pp. 581-593 : 587-591

Giraffaphaenops brevicephalus n. sp.

( Figs. 7–12 )

Material. Holotype male, cave Dalongguan Dong , Dalongguan Tun , Jialong Cun , Gantian Zhen , Leye Xian , Baise Shi, Guangxi Zhuang Autonomous Region, China, 24°34'23.46"N, 106°25'27.96"E, 1238 m in altitude, 15-V-2020, leg. Chenghai Fu, deposited in SCAU . Paratypes: 1 male & 1 female; same data as holotype; deposited in SCAU ; 1 male & 2 females, same locality, 29-VI-2020, leg. Mingyi Tian, deposited in SCAU .

Description. Length: 8.56–8.90 mm including mandibles, or 7.94–8.4 mm excluding mandibles; width: 1.33– 1.69 mm; fore body, head (excluding mandibles) plus pronotum, distinctly longer than elytra. Habitus as in Fig. 7 .

Body yellowish brown to reddish brown, elytra slightly lighter, palps, antennae and tarsi pale; shiny, wholly pubescent including appendages, covered with short and erected setae, except propleura, mesosternum and epipleura, which are glabrous.

Head elongate, nearly triangular in form, widest at 2/5 from the base (including mandibles), a little behind the level of antennal articulation, temples slightly and gradually narrowed posteriad towards the distinct neck constriction, base semicolumn-shaped, constriction about 2/5 as wide as head; head excluding mandibles distinctly shorter than pronotum, but as long as pronotum including mandibles; frontal furrows short but distinct, nearly parallel-sided though slightly divergent posteriorly; only anterior pair of supraorbital pores present, at about the widest level; a pair of suborbital pores present, close to the base of head; clypeus transverse, 6-setose; labrum transverse, distinctly protruded medially, 6-setose; mandibles thin and elongated, right one faintly bidentate; palps thin and very elongated, penultimate palpomeres much longer than the apical ones (1.3 times); the 2 nd labial palpomere bisetose on inner margin, with two additional short setae on outer margin, one at middle and the other at subapex; mentum and submentum completely fused; mentum widely concave basally, mental tooth bifid, with two setae on each side; submentum 13-setose ( Fig. 8A ); antennae filiform, extraordinary long and slender, 10 th and 11 th antennomeres exceeding over elytral apices; 1 st antennomere stout, 2.7 times as long as wide; 1 st subequal to 2 nd in length, about a third as long as 3 rd which is subequal in length to 4 th and 5 th respectively; length of antennomeres gradually shortened from 6 th to 10 th, and 7 th as long as the 11 th. The comparative length ratio of antennomere as follows: 1 st (1.00), 2 nd (1.17), 3 rd (3.17), 4 th (3.25), 5 th (3.08), 6 th (2.92), 7 th (2.67), 8 th (2.25), 9 th (2.08), 10 th (1.83) and 11 th (2.58).

Prothorax extremely elongate, nearly as long as head including mandibles, PrL/HL=0.91–1.02; fore half rodlike prolonged, evenly widened, hind half form oval-like; propleura strongly tumid, making widest at about basal fourth; pronotum narrow and markedly elongate, nearly parallel-sided throughout, basal part distinctly widened; base much wider than front, PbW/PfW=1.39–1.45; pronotum much narrower than prothorax, PtW/PnW=1.33–1.48, and narrower than head, HW/PnW=1.23–1.33, without lateral-marginal setae.

Elytra similar to G. clarkei Deuve, 2002 and G. yangi Tian & Luo, 2015 ( Fig. 9 ) elongate-ovate, about twice as wide as prothorax, much longer than pronotum, EW/PnW=2.21–3.07; widest at about 3/5 from base, strongly convex, but basal part nearly flat, shoulders not well marked; discal setiferous pores absent, preapical pore present, seta short and indistinct; chaetotaxal pattern of the marginal umbilicate pores similar to that of G. clarkei and G. yangi , but the 2 nd pore obviously more closer to 3 rd than to 1 st, preapical pore 1.5 times closer to suture than to margin; scutellum small, scutellar pore present.

Legs slender and long, hind femora shorter than elytra; fore tarsomeres not modified in male; the 1 st tarsomere almost as long as 2 nd– 4 th combined in fore legs, while distinctly longer in middle and hind legs, respectively.

Ventrite IV–VI each with a pair of paramedian setae, VII bearing a pair of marginal setae in male, while two pairs in female.

Male genitalia ( Fig. 10 ): median lobe of aedeagus very similar to that of G. yangi , slender and arcuate, basal orifice large, but apex slightly broader and more blunt, not distinctly constrict ( Fig. 10A ); sagittal aileron small, nearly rounded and semitransparent; inner sac weakly marked, armed with a broad copulatory piece which is about 2/7 as long as the median lobe; in dorsal view, apical lobe slenderer, rounded at apex ( Fig. 10B ); parameres similar to those of G. yangi , the right bearing three long setae at apex, while the left only two; genital ring wide ( Fig. 10C ).

Remarks: G. brevicephalus n. sp. is very similar in prothorax and elytra shape to G. clarkei and G. yangi , but it is easily separated from them by its shorter and broader head ( Fig. 8A ), versus longer and narrower in the latter two species ( Fig. 8B ).

Etymology: “brevi-”+“cephalus”, to indicate its short head of this new species.

Distribution: China (Guangxi). Known only from the cave Dalongguan Dong ( Fig. 11 ). This cave is very close to the village Dalongguan. With a very small and narrow entrance ( Fig. 12A ), then the passage becomes much wider. It is about two hundred meters long before joining an underground river. All of the beetles were discovered and collected in a wet area about four to five dozen meters from the entrance ( Fig. 12 B, C ).

Figures

FIGURE 7. Habitus of Giraffaphaenops brevicephalus n. sp.

FIGURE 8. Head of Giraffaphaenops species, ventral view (A. G. brevicephalus n. sp., paratype, female; B. G. yangi, male).

FIGURE 9. Elytra chaetotaxy of Giraffaphaenops species (A. G. brevicephalus n. sp., male, holotype; B. G. yangi, male; C. G. clarkei, male).

FIGURE 10. Male genitalia of Giraffaphaenops brevicephalus n. sp., holotype (A. median lobe and parameres, lateral view; B. apex of median lobe, dorsal view; C. genital ring, ventral view).

FIGURE 11. Distribution map of the genus Giraffaphaenops.

FIGURE 12. Cave Dalongguan Dong, type locality of Giraffaphaenops brevicephalus n. sp. (A. entrance; B. cave environment; C. Giraffaphaenops brevicephalus n. sp.).