Giraffaphaenops yangi, Tian, Mingyi & Luo, Xiaozhu, 2015

Tian, Mingyi & Luo, Xiaozhu, 2015, A new species of the highly modified hypogean genus Giraffaphaenops Deuve, 2002 (Coleoptera: Carabidae: Trechinae), Zootaxa 3911 (4), pp. 581-588 : 582-583

Giraffaphaenops yangi n. sp.

( Figs. 1–7, 10 )

Material. Holotype male, northwestern Guangxi: Tianlin County: Langping Xiang: Hongxing Cun, cave Shizikou Dadong, 24°36'49.79" N, 106°16'38.16" E, 839 m in altitude, 13 - VI - 2014, leg. Mingyi Tian & Xiaozhu Luo, deposited in the insect collections of South China Agricultural University, Guangzhou ( SCAU); paratype: 1 male, in SCAU.

Length: 8.3–9.0 mm including mandibles, or 8.0– 8.7 mm excluding mandibles; width: 1.7 mm; habitus as in Fig. 1.

Description. Body 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 about basal quarter, a little behind the level of antennal articulation, temples slightly and gradually narrowed posteriad towards the distinct neck constriction, base ringshaped, constriction about 2/5 as wide as head; head excluding mandibles distinctly shorter than pronotum, but longer if mandibles included; head (excluding mandibles) plus pronotum distinctly longer than elytra; frontal furrows short, nearly parallel-sided; only anterior pair of supraorbital pores present, at a little behind the widest level, closer to frontal furrow than to genal margin; a pair of suborbital pores present, not far from the ring-shaped base; clypeus transverse, 6-setose; labrum transverse, distinctly protruded medially, 6-setose; mandibles thin and elongated, right one tridentate; palps thin and very elongated, penultimate palpomeres much longer than the apical ones; 2nd labial palpomere bisetose on inner margin, with two additional short setae near apex; mentum and submentum completely fused; mentum widely concave basally, mental tooth simple; submentum 6-setose; antennae filiform, very long and slender, 10th and 11th antennomeres exceeding over elytral apices; 1st antennomere robust, 2.7 times as long as wide; 1st subequal to 2nd in length, about a third as long as 3rd which is subequal in length to 4th and 5th respectively; length of antennomeres gradually shortened from 6th to 10th, with 11th as long as the 7th.

Prothorax extremely elongate, nearly as long as head including mandibles, comparatively short, PtL/HL=1.01; fore half rod-like prolonged, evenly widened; propleura strongly tumid, making widest at about basal fourth; pronotum narrow and markedly elongate, nearly parallel-sided throughout, except for basal part near the hind angles which are distinctly widened, at the level of the maximum width of prothorax; base much wider than front, PbW/PfW=1.48; pronotum much narrower than prothorax, PtW/PnW=1.62, and narrower than head, HL/ PnL=1.31, without latero-marginal setae.

Elytra elongate-ovate, slightly slenderer than in G. clarkei , about twice as wide as prothorax, much longer than pronotum, EW/PtW=1.42; widest at about 4/7 from base, strongly convex, but basal part nearly flat, shoulders not well marked; dorsal setiferous pores absent, preapical pores present, and short; chaetotaxal pattern of the marginal umbilicate pores similar to that of G. clarkei , but distance between 1st and 2nd almost twice as long as that between 2nd and 3rd; scutellum small, scutellar pores present.

Legs slender and long, hind femora shorter than elytra; fore and mid coxae conically protrudent, more so in the former; fore legs shortest, hind ones longest; fore tarsi not modified in male; 1st fore tarsomere slightly longer than 2nd–4th combined; 1st mid and hind tarsomeres distinctly longer than 2nd–4th combined, respectively; 4th fore tarsomere short, but distinctly longer than wide.

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

Male genitalia ( Figs. 6–7 ): Median lobe of aedeagus very similar to that of G. clarkei , slender and arcuate, basal orifice large, but apex broader and more obtuse; sagittal aileron small, nearly rounded and semitransparent; inner sac not well marked, armed with a broad copulatory piece which is about 2/7 as long as the median lobe; in dorsal view, apical lobe slenderer, and rounded at apex; parameres similar to those of G. clarkei , each bearing three apical long setae.

Female. Unknown.

Remarks. G. y a n g i n. sp. is very similar in the general shape to G. c l a r ke i, but it is easily separated from the latter by the following characteristics: (1) Head broader, temples slightly and gradually narrowed towards the neck which is indistinct (while much slender in G. clarkei , temples strongly constricted and almost straight towards neck which is much narrower and distinct) ( Figs. 2–3 ); (2) Fore part of pronotum stouter and nearly straight throughout, not constricted at about 3/5 from base (while thinner in G. clarkei , gradually narrowed posteriad, and distinctly constricted at about 3/5 from base) ( Figs. 4–5 ); (3) Elytra much slenderer than in G. clarkei ; and (4) Distance between 1st and 2nd of the marginal umbilicate pores almost twice as long as that between 2nd and 3rd (while distance between 1st and 2nd subequal to that between 2nd and 3rd in G. clarkei ).

Etymology. This interesting species is dedicated to Mr. Zaihua Yang, the owner of Shizikou Dadong, to thank his assistance during our surveys in the cave.

Distribution. The cave Shizikou Dadong, northeastern Tianlin County, northwestern Guangxi ( Fig. 14 )

Shizikou Dadong ( Figs. 8, 9, 11 ) is a show cave, managed by Mr. Z.H. Yang, a young local farmer. It is largely opened at hill slope about fifty meters above a valley near Hongxing village. After one hundred meters from the entrance, the pathway is down grade to an underground river. It is about 1600 meters long, with some beautiful stone columns and stalagmites. The two blind beetles were collected under stone along the river, about 700 meters far from the entrance ( Fig. 9 ). Shizikou Dadong holds a very important cave fauna ( Figs. 10, 12, 13 ): apart from Giraffaphaenops yangi , three species of cave fishes including Sinocyclocheilus tianlinensis Zhou, Zhang & He, 2003 , and four millipede species are also living in the cave. Fortunately, most part of the cave remains more or less at natural state.

Figures

FIGURES 14. Distribution of the genus Giraffaphaenops (square: G. clarkei; round: G. y a n g i n. sp.; a. cave Jinyin Dong; b. cave Maping Dong; c. cave Ganhan Dong; d. cave Yanwu Dong; e. cave Shizikou Dadong).

FIGURES 8 – 13. Cave Shizikou Dadong and cavernicolous animals. 8. entrance; 9. underground river, arrowhead showing where the type specimens were collected; 10. Giraffaphaenops yangi n. sp.; 11. a stone column; 12. Sinocyclocheilus tianlinensis, one of the most modified cave fishes in China, by courtesy of Prof. Jiahu Lan; 13. millipede Eutrichodesmus sp.

FIGURES 2 – 7. Giraffaphaenops species. 2 and 4. G. y a n g i n. sp.; 3 and 5. G. clarkei; 2 – 3. head and prothorax, dorsal view; 3 – 4. Prothorax, lateral view; 6. median lobe and parameres of G. yangi n. sp., lateral view; 7. apical lobe of median lobe of G. yangi n. sp., dorsal view.