Xestopus gutangensis Zhu & Kavanaugh, 2021

Zhu, Pingzhou, Kavanaugh, David H. & Liang, Hongbin, 2021, Notes on the genus Xestopus from China, with description of a new species (Carabidae, Sphodrini, Dolichina), ZooKeys 1009, pp. 139-151 : 139

Xestopus gutangensis Zhu & Kavanaugh sp. nov. Figures 1 , 3-7 , 8-10 , 19

Type locality.

China, Xizang: Mêdog (29.46414°N, 95.73563°E), altitude 2025 m.

Type material.

Holotype. Мale (IZAS), body length = 16.9 mm, board mounted, genitalia dissected and glued on plastic film pinned under specimen, "Xizang, Nyingchi Prefecture, Mêdog County, Gutang Township, Xingkai village, 29.46414°N, 95.73563°E "; "2025 m, 2019.VIII.15 N, Liang H.B. & Xu Y. lgt., Institute of Zoology, IZAS"; "HOLOTYPE ♂ Xestopus gutangensis sp. nov. des. ZHU & KAVANAUGH 2020" [red label]. Paratypes (34 males and 45 females): one female (IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, Bapo, 1412 m, 27.73902°N, 098.34975°E, 26 October 2004, Stop # LHB-2004-033, H.-B. Liang collector"; 14 males and 13 females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, Bapo, Mulangdang, 1355 m, 27.75256°N, 098.34745°E, 4 November 2004, Stop # LHB-2004-046, H.-B. Liang collector"; one male and three females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.6 km N of Dizhengdang village on Dulong Jiang, 28.08442°N, 098.32652°E, 1880 m, 29 October 2004, Stop # DHK-2004-061B, D.H. Kavanaugh, G. Tang & D.-Z. Dong collectors"; three females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.6 km N of Dizhengdang village on Dulong Jiang, 28.08442°N, 098.32652°E, 1880 m, 30 October 2004, Stop # DHK-2004-064, D.H. Kavanaugh, G. Tang & D.-Z. Dong collectors"; one male and three females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, west bank of Dulong Jiang at Elideng village, 1640 m, 28.00287°N, 098.32145°E, 3 November 2004, Stop # DHK-2004-073, D.H. Kavanaugh, G. Tang & D.-Z. Dong collectors"; one male (CAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.5 km N of Kongdang, 1500 m, 27.88111°N, 098.34063°E, 25 October 2004, Stop # DHK-2004-057B, D.H. Kavanaugh, H.-B. Liang & D.-Z. Dong collectors"; two males and three females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.5 km N of Kongdang, 1500 m, 27.88111°N, 098.34063°E, 25 October 2004, Stop # DHK-2004-057C, D.H. Kavanaugh, Q.-B. Hou, H.-B. Liang, D.-Z. Dong & G. Tang collectors"; six males and eight females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, Dulong Jiang at Xianjiudang village, 1580 m, 27.94092°N, 098.33340°E, 4 November 2004, Stop # DHK-2004-074, D.H. Kavanaugh, M.A. Dixon, G. Tang & D.-Z. Dong collectors"; one male and five females (IZAS), the same collecting data as holotype; six males and four females (IZAS, CAS), "CHINA, Tibet, Bomi, Yi’ong, Tangmai bridge, Beach of Yi’ong Zangbo, 30.09633°N, 95.06577°E "; "2035 m, 2006.8.30 N, Liang H.B., Song Z.S., Institute of Zoology, Chinese Acad. of Sciences"; one male and one female (IZAS), "CHINA, Xizang, Nyingchi, Bomi, Yi’ong, Tangmai bridge, Beach of Yi’ong Zangbo, 30.09633°N, 95.06577°E "; "2035m, 2020.VIII.31 N, Liang H.B. & Zhang N. lgt., Institute of Zoology, Chinese Acad. of Sciences"; one male and one female (IZAS), "CHINA, Xizang, Nyingchi, Bomi, Yi’ong, Tangmai bridge, Beach of Yi’ong Zangbo, 30.09633°N, 95.06577°E "; "2035 m, 2020.IX.1 N, Liang H.B. & Zhang N. lgt., Institute of Zoology, Chinese Acad. of Sciences"; All paratypes also bear the following label: "PARATYPE Xestopus gutangensis sp. nov. des. ZHU & KAVANAUGH 2020" [red label].

Diagnosis.

Dorsum black, elytra with more or less bluish metallic luster. Anterior supraorbital setae present. Pronotum with lateral margins faintly sinuate before posterior angles. Apices of elytra rounded (Fig. 6 ). Hind wings full-sized. Metepisternum long and narrow.

Comparisons.

This new species is most similar to Xestopus cyaneus , sharing the bluish elytra and full-sized hind wings, which are distinctive features in the genus. X. gutangensis sp. nov. can be readily distinguished from X. cyaneus by: (1) anterior pair of supraorbital setae present; (2) apices of elytra rounded; (3) apical lamella of median lobe strongly bent ventrally like a hook; (4) endophallus without a densely setose area on left side; (5) gonocoxite II of female ovipositor very long. Supernumerary setae have been found in some X. gutangensis specimens in the area of the posterior supraorbital setae, on the pronotal lateral margins and posterior angles, and on the external margin of gonocoxite II (as ensiform setae). These additional setae were not observed on any of the specimens of X. cyaneus that we examined.

Description.

BL = 15.7-18.0 mm, BW = 6.4-7.8 mm. Dorsum (Fig. 1 ) black, elytra with more or less bluish metallic luster, very faint in some specimens; appendages dark, antennomeres 4-11, labial and maxillary palpi, apex of mouthparts and tarsomeres dark brown; venter black, without metallic luster. Head, pronotum and elytra with strong isodiametric microsculpture.

Head with vertex smooth; frontal impressions shallow and curved, in front of eyes; clypeus with anterior margin faintly emarginate; labrum with anterior margin straight; temporae slightly swollen behind eyes; both anterior and posterior pairs of supraorbital setae present (two pairs of posterior supraorbital setae present in a few specimens); antennae long and slender, extended to basal one-third of elytra.

Pronotum cordiform, slightly transverse, PW/PL = 1.38-1.55, widest near anterior quarter; anterior margin markedly concave, slightly wider than basal margin, PAW/PBW = 1.13-1.33, lateral margins broadly rounded before middle, then distinctly narrowed to base, faintly sinuate before posterior angles, PW/PBW = 1.31-1.50, lateral margins with one pair of setae at widest points and posterior angles respectively (with an additional seta on one or both sides and at either or both widest points and posterior angles), basal margin straight; anterior angles rounded, moderately extended forward, posterior angles distinctly obtuse; disc glabrous, gently convex; median line fine but clearly defined; basal fovea large and deep, without punctures but with some wrinkles; lateral explanations very wide and impunctate.

Elytra wide, EL/EW = 1.44-1.59, moderately dilated towards apex, widest near posterior third, apices rounded; basal margination complete and straight; humeral angles rounded, without teeth; intervals moderately convex, striae shallow and impunctate; parascutellar striae well developed and short, between suture and stria 1; parascutellar pores present; interval 3 without setigerous pores; umbilicate series on interval 9 composed of approximately 25 setigerous pores, continuous in middle. Hind wings fully sized.

Venter. Propleuron, mesoepisternum, and metepisternum glabrous, metepisternum long and narrow; all abdominal sternites with a few shallow wrinkles laterally.

Legs long and slender, all tarsi smooth, claws distinctly denticulate in basal half.

Male genitalia. Median lobe (Figs 3 , 7 ) long, slender, and straight but slightly bent ventrally; apical orifice opened dorsally, very long and wide, from basal bulb to apical lamella; in dorsal view (Fig. 3A ), left and right margins both straight, apical lamella long, length about twice its basal width, apex rounded; in left lateral view (Fig. 3B ), ventral margin weakly expanded in the middle, apical portion slightly bent dorsally and then strongly bent ventrally like a hook at apex. Left paramere (Fig. 5 ) large and round, with a membranous filament at apex. Right paramere (Fig. 4 ) markedly styloid and curved, the angle between basal portion and apical portion near 90°; apical portion moderately bent ventrally, apical hook rounded. Endophallus (Fig. 7 ) simple, with only a single large lobe, straight, extended right at an angle of about 30° relative to longitudinal axis of the median lobe in dorsal view (Fig. 7D ); surface smooth, without setae or scales; gonopore and gonopore lobe folded in this specimen.

Female genitalia (Figs 8-10 ). Gonocoxite II of ovipositor very long, length about four times basal width, with one ensiform seta at external margin in most specimens (two ensiform setae in a few specimens and ensiform seta very small in some specimens), sensory pit of apical gonocoxite absent. Bursa copulatrix very large, rounded. Spermatheca moderately long and tube-like, length about five times maximum width.

Distribution

(Fig. 19 ). This species is known from Bomi and Mêdog counties, Xizang, and from the northern part of the Dulongjiang valley in Gongshan County, Yunnan.

Etymology.

The new species is named for Gutang Township, where the type locality, Mêdog, is located.

Affinities.

Among all Xestopus species, only X. gutangensis and X. cyaneus have the bluish elytra and full-sized hind wings. Thus, a close relationship of these two species is likely, and the absence of anterior supraorbital setae in the latter is clearly apomorphic within the genus.

Figures

Figure 19. Distribution map for Xestopus from China: X. gutangensis sp. nov. (blue); X. cyaneus (red).

Figures 1, 2. Holotypes of Xestopus spp. 1 X. gutangensis Zhu & Kavanaugh, sp. nov. (male, Xizang, IZAS) 2 X. cyaneus Sciaky & Facchini, 1997 (female, Xizang, CRS). Scale bar: 5.0 mm.

Figures 3 - 18. Morphological features of Xestopus spp. 3 - 6 holotype of X. gutangensis Zhu & Kavanaugh, sp. nov. 7 - 10 paratype of X. gutangensis Zhu & Kavanaugh, sp. nov. 11 - 18 X. cyaneus Sciaky & Facchini, 1997 3, 11 median lobe of aedeagus A dorsal view B left lateral view 4, 12 right paramere 5, 13 left paramere 6, 14 apex of left elytron 7, 15 endophallus A left lateral view B ventral view C right lateral view D dorsal view 8, 16 female reproductive system 9, 17 female tergum VIII 10, 18 female sternum VIII. Scale bars: 1.0 mm.