Xestopus cyaneus Sciaky & Facchini, 1997

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 cyaneus Sciaky & Facchini, 1997 Figures 2 , 11-18 , 19

Xestopus cyaneus Sciaky & Facchini, 1997: 235 (type locality: Anjula Pass, SE Tibet, China; holotype in CRS); Lorenz 1998: 373 (catalogue); Hovorka and Sciaky 2003: 530 (catalogue); Lorenz 2005: 399 (catalogue); Hovorka 2017: 769 (catalogue).

Material examined.

Total 196 specimens. Holotype of Xestopus cyaneus Sciaky & Facchini, 1997, by monotypy (CRS): female, body length = 16.1 mm, board mounted, "Tibet S. Or. Anjula Pass 9.7.95 leg. Tarasov", "HOLOTYPUS Xestopus cyaneus n. sp. Det. Sciaky 1996" [red label]. One male and one female (CRS), "China, Tibet, Motuo co., Hanmi, VI.2013"; one male and one female (CRS), "China, Tibet, Motuo co., Hanmi, VIII.2013"; one male and three females (CRS), "China, Tibet, Linzhi area, Linzhi, 2000 m, VIII-IX.2019"; three females (CRS), "China, Tibet, Linzhi area, Mt. Serkyla, 3000-4000 m, VIII.2018"; four females (CRS), "China, Tibet, Bomi county, 2500 m, VIII.2019"; one female (IZAS), "China, Yunnan, Fugong, Lishadi Town, 4km below Shibali Road, 27.15727°N, 98.79784°E, 2280 m, 2005.VIII.11 N, Tang G lgt."; two males and three females (CAS, IZAS), "CHINA, Yunnan, Fugong County, Lishadi Township, 4 km E of Shibali on Shibali Road, 2280 m, 27.15727°N, 098.79784°E, 11 August 2005, Stop# DHK-2005-076A, D. Z. Dong collector"; five males and two females (CAS, IZAS), "CHINA, Yunnan, Fugong County, Lishadi Township, Shibali Road from Galadi village to 2.5 km W, 27.13863°N, 098.82174°E to 27.14286°N, 098.82001°E, 1845-1940 m, 9 August 2005, Stop #DHK-2005-071, D.H. Kavanaugh, H.B. Liang, & D. Z. Dong collectors"; one female (IZAS), "CHINA, Yunnan, Fugong County, Lishadi Township, Yamu He at Shikuliudi village, 27.11876°N, 098.83118°E, 1800 m, 26 April 2004, Stop #LHB-2004-008B, Liang H.-B. collector"; one female (CAS), "CHINA, Yunnan, Fugong County, Lumadeng Township, 4 km E of Lao Shibali on Lao Shibali Road, 2120 m, 27.09700°N, 098.80570°E, 21 August 2005, Stop# DHK-2005-101, D. Z. Dong collector"; three males and three females (CAS, IZAS), "CHINA, Yunnan, Fugong County, Lumadeng Township, 1.5 km above confluence of North and South Forks of Yamu He on Lao Shibali Road, 1825 m, 27.11992°N, 098.83150°E, 15 August 2005, at night, Stop# LHB-05-55, H.B. Liang collector"; three females (IZAS), "China, Yunnan, Gongshan, Dulongjiang, Maku village, 27.684453°N, 98.30547°E, 1691 m, 2019. VIII.21 N, Liang HB & Xu Y lgt."; one female (IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, Maku, 1823 m, 27.68553°N, 098.30425°E, 2 November 2004, Stop # LHB-2004-042, H.-B. Liang collector"; three males and three females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, Maku village, 1800 m, 27.68498°N, 098.30299°E, 28 August 2006, Stop #DHK-2006-100, D.H. Kavanaugh, J.A. Miller, & D.Z. Dong collectors"; 43 males and 35 females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, Maku village, 27.68545°N, 098.30419°E, 1815 m, 2 September 2006, Stop #DHK-2006-119, Y. Liu & D. Z. Dong collectors"; ten males and nine females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.1 airkm NW of Maku Yakou, 1880 m, 27.67937°N, 098.29617°E, 31 August 2006, Stop #DHK-2006-110, Y. Liu collector"; nine males and seven females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.5 air km WSW of Maku village on trail to Maku Yakou, 1845 m, 27.68310°N, 098.30038°E, 29 August 2006, Stop #DHK-2006-103, D. H. Kavanaugh collector"; eight males and five females (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.5 air km WSW of Maku village on trail to Maku Yakou, 1845 m, 27.68310°N, 098.30038°E, 29 August 2006, Stop #DHK-2006-108, D.H. Kavanaugh, J.A. Miller, D.Z. Dong, & Y. Liu collectors"; two males (CAS, IZAS), "CHINA, Yunnan, Gongshan County, Dulongjiang Township, 0.5 airkm WSW of Maku village on trail to Maku Yakou, 1845 m, 27.68310°N, 098.30038°E, 29 August 2006, Stop #DHK-2006-116, D. Z. Dong collector"; one female (CAS), "CHINA, Yunnan Province, Gaoligong Shan, Nujiang Prefecture, Nujiang State Nature Reserve, Qiqi area, 10.3 air km W of Gongshan, 27.71542°N, 98.56529°E, 2010 m, 9-14 July 2000, Stop#00-22C, D.H. Kavanaugh, C.E. Griswold, Liang H.-B., D. Ubick, & Dong D.-Z. collectors"; one male (IZAS), "China, Tibet, Bomi, Yi’ong, Tongmai bridge, 30.09633°N, 95.06577°E, 2035m, 2006.VIII.30 N, Liang HB & Song ZS lgt."; one male (IZAS), "CHINA, Xizang, Nyingchi, Bomi, Yi’ong, Tangmai bridge, Beach of Yi’ong Zangbo, 30.09633°N, 95.06577°E, 2035 m, 2020.VIII.31 N, Liang H.B. & Zhang N. lgt."; 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."; one male (IZAS), "China, Tibet, Mêdog, Dagmo road to Gutang, 29.5150°N, 95.4642°E, 1679 m, 2016.VIII.16, Qiu TF lgt."; one female (IZAS), "China, Xizang, Zhamo-Mêdog road 78K, light trap, 29.66570°N, 95.49577°E, 2104 m, 2017.VIII.15 N, Liang HB lgt."; three males and three females (IZAS), "China, Xizang, Nyingchi City, Mêdog County, Dagmo Township, Zhamo-Mêdog road 80K, 29.657947°N, 95.489994°E, 2073.40 m, 2020.IX.17 N, Liang H.B. & Xu Y. lgt."; one male (IZAS), "China, Xizang, Nyingchi City, Mêdog County, Dagmo Township, Zhamo-Mêdog road 80K, 29.657947°N, 95.489994°E, 2073.40 m, 2020.IX.17 N, Zhang Neng lgt.";one female (CCCC), "China, Xizang, Bomi, Tongmai, 2262 m, 2016.VII.24, Lu YQ lgt."; two males and two females (CCCC), "China, Xizang, Bomi, Yi’ong, 2380 m, 2016.VII.26, Lu YQ lgt."; one male and two females (CCCC), "China, Xizang, Mêdog, 80K, 2350 m, 2016.VII.30, Lu YQ lgt.".

Diagnosis.

Dorsum (Fig. 2 ) black, elytra with more or less bluish metallic luster. Anterior pair of supraorbital setae absent (an anterior supraorbital seta present on one or both sides in a very few specimens). Pronotum with lateral margins very faintly sinuate before posterior angles. Apices of elytra acute (Fig. 12 ). Hind wings full-sized. Metepisternum long and narrow.

Supplementary description.

BL = 15.4-18.6 mm, BW = 6.2-7.4 mm. PW/PL = 1.37-1.54. PW/PBW = 1.40-1.59. PAW/PBW = 1.19-1.44. EL/EW = 1.51-1.68.

Male genitalia. Median lobe (Figs 11 , 15 ) long, stout and straight but slightly bent ventrally; apical orifice broadly open dorsally, very long and wide, from basal bulb to apical lamella; in dorsal view (Fig. 11A ), left and right margins both straight, apical lamella very long, length about three times as its basal width, moderately dilated in the middle, apex acute; in left lateral view (Fig. 11B ), ventral margin straight, not expanded in the middle, apical portion slightly bent ventrally, apical lamella thick and straight. Left paramere (Fig. 13 ) large and round, with a membranous filament at apex. Right paramere (Fig. 12 ) strongly styloid and curved, the angle between basal portion and apical portion nearly 100°; apical portion straight, apical hook acute. Endophallus (Fig. 15 ) simple, only a single large lobe, straight, extended left at an angle of about 45° relative to longitudinal axis of the median lobe in dorsal view (Fig. 15D ); surface with a densely setose area present on left side, without scales; gonopore lobe long and narrow, located at apex of endophallus, gonopore directed toward apex.

Female genitalia (Figs 16-18 ). Gonocoxite II of ovipositor moderately long, length about three times basal width, with one ensiform seta at external margin, sensory pit of apical gonocoxite absent. Bursa copulatrix large and elongate. Spermatheca moderately long and tube-like, length about five times maximum width.

Distribution

(Fig. 19 ). This species is known from Xizang (Bomi and Mêdog counties) and Yunnan (Gongshan and Fugong, new provincial record). The records from Sichuan cited by Hovorka and Sciaky (2003) and Hovorka (2017) is clearly wrong.

Remarks.

The number of pairs of supraorbital setae is a very important character within Carabidae for both classification and systematics. In most members of the tribe Harpalini , only one pair of supraorbital setae is present at a middle position in relation to the diameter of the eyes, while most other ground beetles have two pairs of supraorbital setae. A few non-harpaline carabids lack one pair of supraorbital setae, but the other pair is present either in an anterior or a posterior position relative to the eyes instead of at the middle position as in Harpalinae . It is, therefore, usually easy to determine whether it is the anterior or posterior pair of supraorbital setae that is missing. Variation in this apparently apomorphic feature does not appear to have much value in high-level phylogeny. For example, members of genus Reflexisphodrus Casale, 1988 and genus Eosphodrus Casale, 1988 ( Sphodrini , Sphodrina ) lack the posterior pair of supraorbital setae while those of Pterostichus subgenus Unitrichus Sciaky, 1997 ( Pterostichini ) lack the anterior pair just like most members of Xestopus cyaneus . The single species of Unitrichus , Pterostichus platyops Sciaky, 1997, from Yunnan, China, is distinguished from members of other subgenera of Pterostichus by the absence of the anterior pair of supraorbital setae and the presence of many setae at the middle of mentum. We have found a second, undescribed species from Yunnan, China with the similar appearance of P. platyops and many setae present at the middle of mentum, but with the anterior pair of supraorbital setae present (unpublished data), as in Xestopus gutangensis Zhu & Kavanaugh, sp. nov. These two examples show that differences in the number of supraorbital setae between closely related species is possible, even if it is rarely seen.

In our examination of 260 specimens of X. cyaneus and X. gutangensis Zhu & Kavanaugh, sp. nov., we found only five that had abnormal numbers of supraorbital setae for their species assignment based on other characters. All were clearly X. cyaneus based on the shape of the elytral apex and features of either male or female genitalia. Three of these, including one male from Xizang and one male and one female from Yunnan, had an anterior supraorbital seta present on one side but absent from the other. In addition, we found one female from Xizang and one female from Yunnan that had anterior supraorbital setae present on both sides. Consequently, the presence or absence of anterior supraorbital setae is slightly less reliable for distinguishing these two species than are the shapes of the elytral apices and male and female genitalia.

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.