Broscodera (Sinobrosculus) chukuai Kavanaugh and Liang, 2021

Kavanaugh, David H. & Liang, Hongbin, 2021, Inventory of the Carabid Beetle Fauna of the Gaoligong Mountains, Western Yunnan Province, China: Species of the Tribe Broscini (Coleoptera: Carabidae)., Proceedings of the California Academy of Sciences 67 (4), pp. 85-182 : 99-103

1. Broscodera (Sinobrosculus) chukuai Kavanaugh and Liang , sp. nov.

Figures 5c , 8b , 11 , 12 , 40 , 48-50

Type material. Holotype, a male, in IOZ, labeled: “ CASENT 1026170 ”/ “ CHINA, Yunnan, Gongshan County, Bingzhongluo Township, SW slope of Kawakarpu Shan , 0.3 km NNE of Chukuai Lake, N27.98393° / E098.47491° ”/ “ 3745 m, 19 August 2006, Stop #DHK-2006-081 D.H. Kavanaugh, J.A. Miller & D.Z. Dong collectors”/ “HOLOTYPE Broscodera (Sinobrosculus) chukuai Kavanaugh & Liang sp. nov. designated 2021” [red label] . Paratypes (a total of 31): three males and ten females ( CAS, IOZ) labeled: same as holotype except first label: “ CASENT 1026167 ” to “ CASENT 1026169 ” and “ CASENT 1026171 ” to “ CASENT 1026180 ”, respectively ; three males and four females ( CAS, IOZ) labeled: “ CASENT 1026771 ” to “ CASENT 1026773 ” and “ CASENT 1026774 ” to “ CASENT 1026777 ”, respectively/ “ CHINA, Yunnan, Gongshan County, Bingzhongluo Township, SW slope of Kawakarpu Shan at Chukuai Lake , 3720 m,”/ “ N27.98121° / E098.47580°, 18 August 2006, Stop #DHK-2006-079 D.H. Kavanaugh, J.A. Miller, D.Z. Dong & Y. Liu collectors” ; two males ( CAS, IOZ) labeled: “ CASENT 1024860 ” and “ CASENT 1024861 ”, respectively/ “ CHINA, Yunnan, Gongshan County, Bingzhongluo Township, SW slope of Kawakarpu Shan , on slope NE of Chukuai Lake, 3950 m,”/ “ N27.98206° / E098.48027°, 20 August 2006, Stop #DHK-2006-086 Y. Liu, P. Hu, D.Z. Dong & J. Wang collectors” ; one male and two females ( CAS, IOZ) labeled: “ CASENT 1024904 ” and “ CASENT 1024905 ” to “ CASENT 1024906 ”, respectively/ “ CHINA, Yunnan, Gongshan County, Bingzhongluo Township, SW slope of Kawakarpu Shan , 0.8 km N of Chukuai Lake, N27.98785° / E098.47322° ”/ “ 3920 m, 20 August 2006, Stop #DHK-2006-088 D.H. Kavanaugh, J.A. Miller, J. Xiong, & C.H. Li collectors” ; one male ( CAS) labeled: “ CASENT 1025034 ”/ “ CHINA, Yunnan, Gongshan County, Bingzhongluo Township, SW slope of Kawakarpu Shan , 0.9 km N of Chukuai Lake,”/ “ 27.99005°/ E098.47518°, 4035 m, 21 August 2006 Stop #DHK-2006- 090 D.H. Kavanaugh collector” ; one male and one female ( CAS, IOZ) labeled: “ CASENT 1025823 ” and “ CASENT 1025824 ”, respectively/ “ CHINA, Yunnan, Gongshan County, Bingzhongluo Township, SW slope of Kawakarpu Shan , 0.3 km SW of Chukuai Lake at campsite, N27.97686° / E098.47799° ”/ “ 3750 m, 19 August 2006, Stop #DHK-2006-082 Y. Liu collector; two females ( CAS, IOZ) labeled: “CASENT 1017826” and “ CASENT 1017827 ”, respectively/ “ CHINA, Yunnan, Fugong County , Lumadeng Township , second cirque S of Shibali Yakou at border post “31”, N27.20333° / E098.69303° ”/ “ 3710 m, 17 August 2005, Stop #DHK-2005-095, H.B. Liang, D.Z. Dong, & J.F.Zhang collectors” ; one female ( IOZ) labeled: “ CASENT 1018367 ”/ “ CHINA, Yunnan, Fugong County, Lishadi Township, headwaters of North Fork Yamu He just E of Shibali Yakou, 3450 m,”/ “ N27.21034° / E098.70141°, 7 August 2005, Stop# LHB-05-52, H.B. Liang & J.F.Zhang collectors. All paratypes also bear the following label: “PARATYPE Broscodera (Sinobrosculus) chukuai Kavanaugh & Liang , sp. nov. designated 2021” [yellow label].

Type locality. China, Yunnan, Gongshan County, Bingzhongluo Township, SW slope of Kawakarpu Shan , Chukuai Lake area .

Derivation of species name. The species epithet, chukuai , is a noun in apposition and derived from the name of a lake on the southwestern slope of Kawakarpu Shan, in the vicinity of which most of the specimens of the type series were found.

Diagnosis. Adults of this species ( Fig. 11a ) can be distinguished from those of other species in the region by the following combination of character states: size small, BL male = 8.0–8. 8 mm, female = 7.8–9. 5 mm; body color reddish-brown; head ( Fig. 5c ) with eyes small, only slightly convex, their diameter slightly less than length of tempora; frontal furrows deeply impressed, smooth and impunctate; vertex with post-temporal transverse sulcus deep, sharply impressed and only narrowly punctate along bottom of sulcus; gula smooth, without transverse grooves; antennomere 3 with pubescence on apical half; pronotum with posterior transverse impression shallow and vaguely delineated; elytra with lateral margins slightly arcuate, microsculpture comprised of distinct and deeply impressed isodiametric meshes; hindwings slightly reduced; prosternum, proepisternum, metasternum, and metepisternum smooth or faintly punctulate; hind trochanter unisetose; abdominal sternite VI of female with two pairs of apicoparamedial setae. Male genitalia as in Fig. 12 ; median lobe with ventral surface moderately concave with ventrolateral edges elevated and distinctly flanged near mid-length, especially on right edge; apex of apical lamella evenly rounded in lateral view.

Description. Fig. 11a . Size small, BL male = 8.0–8. 8 mm, female = 7.8–9. 5 mm, ratio EL/PL = 2.2-2.4. Body color reddish brown, all appendages reddish brown.

Head. Fig. 5c . Eyes small, only slightly convex, their diameter slightly less than length of tempora. Frontal furrows deeply impressed, narrow, smooth, impunctate. Vertex with post-temporal transverse sulcus deep, sharply impressed and only narrowly punctate along bottom of sulcus. Tempora roundly subangulate. Gula without transverse grooves.

Pronotum. Markedly cordate, moderately convex, narrowed posteriorly, widest distinctly anterior to middle of discal region; apical margination absent; lateral margination present, narrow, distinctly delineated throughout pronotal length; basal margination absent; anterior transverse impression absent or shallow and indistinct; median longitudinal impression moderately impressed; posterior transverse impression shallow and vaguely delineated; anterior region smooth, or faintly and sparsely rugulose; pronotal base coarsely punctate and rugulose; one pair of midlateral pronotal setae present at anterior one-third to one-fourth, one pair of basolateral pronotal setae present slightly anterior to basal angles.

Elytra. Elytral silhouette symmetrically subovoid, widest at or just behind middle, ratio EL/EW = 1.5–1.7, greatest elevation above lateral margin (in lateral view) posterior to middle; humeri distinctly present, roundly obtuse; lateral margins slightly arcuate; parascutellar striole present, short, distally merged in a distinct jog with free base of stria 1. Nine striae present; stria 1 moderately deeply and sharply impressed; striae 2 to 3, 4, or 5 moderately impressed in basal two-thirds and successively more shallowly impressed in apical third, striae 3 to 8 successively more shallowly impressed laterally and apically; stria 9 divergent medially from lateral groove in apical half; stria 1 moderately or finely punctate at least in basal half; striae 2 to 8 shallowly and sparsely punctate in basal two-thirds and successively more shallowly and sparsely punctate in apical third. Parascutellar setiferous pore absent, discal setae absent, umbilicate series comprised of one subhumeral and three subapical setae. Elytral microsculpture comprised of distinct and deeply impressed isodiametric sculpticells.

Hindwings. Slightly reduced, incapable of supporting flight.

Thoracic venter. Prosternum and proepisternum smooth or faintly punctulate, mesosternum and mesepisternum coarsely but sparsely punctate, metasternum and metepisternum smooth or faintly punctulate. Metepisternum ratio ML/MW = 2.0–2.1.

Legs. Hind trochanter unisetose. Tarsomeres with sparse long setae dorsally; tarsomere 5 with a single subapical pair of setae ventrally; male pro- and mesotarsi each with small pads of adhesive setae on tarsomeres 1 and 2.

Abdomen. Sternite VI of male with one pair of apicoparamedial setae, female with two pairs.

Male genitalia. As in Fig. 12 .

Comments. Members of this species can be distinguished from those of B. gaoligongensis by the features listed above in the key and diagnosis. They differ from members of all three subspecies of B. dreuxi from Sichuan Province, China in having a lighter body color (reddish-brown rather than dark brown to piceous), head with impunctate (rather than punctate) frontal furrows and the post-temporal transverse sulcus only narrowly (rather than more broadly) punctate, the elytral striae only finely (rather than more coarsely) punctate, and the median lobe of the male genitalia shorter, thicker, and slightly more arcuate in lateral view compared with the illustration provided by Deuve (1998:228). They differ from members of Broscodera morvani Deuve, 2004 from Gansu Province, China in having the eyes smaller, their diameter less than the length of the tempora (rather than greater than the temporal length), the antennae with antennomere 2 (the pedicel) longer, antennomere 3 with pubescence in its apical half (rather than without pubescence in addition to the apical setal whorl), the pronotum relatively longer and with a single midlateral seta on each side (rather with than two or three such setae), the elytral silhouette elongate-subovid with the lateral margins less rounded (rather than shorter, more ovoid, and with more markedly rounded lateral margins), and the median lobe of the male genitalia shorter, thicker, and more arcuate in lateral view (compared with the illustration provided for B. morvani ( Deuve 2004, Fig. 3 ). Members of B. chukuai differ from those of Broscodera holzschuhi Wrase, 1995 from Nepal in having smaller eyes, their diameter less than the length of the tempora (rather than greater than the temporal length), the pronotum relatively shorter and broader and widest distinctly anterior to mid-length (rather than closer to mid-length), and the elytral silhouette relatively shorter, broader, laterally more evenly curved throughout, and widest at or closer to midlength (rather than laterally nearly straight in basal half and more curved posteriorly and widest near two-thirds elytral length). We have not examined a male of B. holzschuhi for comparison of the genitalia.

Habitat distribution. Members of this species have been found under stones on open slopes above treeline, under deeply embedded stones on organic substrate in alpine tundra areas and near snow patches ( Fig. 40a ), and under stones on the upper banks of meltwater streams and on adjacent tundra flats. Specimens collected in Fugong County near Shibali Yakou were found under stones on organic soil along a small stream and in bamboo thickets ( Fig. 40b ). Within the Gaoligong Shan region, this species occurs at relatively high elevations, with our records documenting its occurrence in the 3450 to 4035 m range ( Fig. 49 ).

Geographical distribution within the Gaoligong Shan. Fig. 11b . We examined a total of 32 specimens (12 males and 20 females) from the northern to the northcentral part of the Gaoligong Shan in Fugong and Gongshan Counties. Our records from Gongshan and Fugong Counties are on the eastern side of the range (in Core Areas 2 and 3, respectively ( Fig. 48 ) (see Type material above for exact collection data).

Overall geographical distribution. This species currently is known only from the northern to northcentral part of the Gaoligong Shan, in western Yunnan Province, China.

Geographical relationships with other Broscodera species. As noted below for B. gaoligongensis , the known geographical range of that species partially overlaps with that of B. chukuai , but they have not been found together ( Fig. 50 ) and appear to occupy non-overlapping altitudinal ranges. No other described species of Broscodera has been recorded from Yunnan Province.

Figures

Figure 11. Broscodera chukuai sp. nov. a. Habitus (CASENT1026168; NNE of Chukuai Lake, Bingzhongluo, Gongshan County, Yunnan, China), dorsal aspect, scale line = 1.0 mm; b. Map showing locality records (blue circles) for this species in the Gaoligong Shan region, scale line = 100 km.

FIGURE 5. Forebody of broscine carabids, dorsal aspect. a. Eoboscus bhutanensis Morvan (CASENT1019340; Lishadi Township, Fugong County, Yunnan, China); b. Broscus punctatus (Dejean) (CASENT1011066; Heiwadi, Cikai Township, Gongshan County, Yunnan, China); c. Broscodera chukuai sp. nov. (CASENT1026168; NNE of Chukuai Lake, Bingzhongluo Township, Gongshan County, Yunnan, China); d. Broscodera gaoligongensis sp. nov. (CASENT1020104; South Fork of Yamu He, Lumadeng Township, Fugong County, Yunnan, China).

FIGURE 8. Left metatrochanter, broscine species, ventral aspect. a. Broscodera gaoligongensis sp. nov. (Yaojiaping, Lushui County, Yunnan, China); b. Broscodera chukuai sp. nov. (CASENT1026771; Chukuai Lake, Bingzhongluo, Gongshan County, Yunnan, China); c. B. bicoloratum sp. nov. (CASENT1034187; Qiqi-Dulong Yakou, Cikai Township, Gongshan County, Yunnan, China); d. B. ribbei Putzeys (CASENT1000578; Nankang Yakou, Longyang County, Yunnan, China).

FIGURE 12. Male genitalia, Broscodera chukuai sp. nov. (CASENT1026169; NNE of Chukuai Lake, Bingzhongluo, Gongshan County, Yunnan, China). a. Right paramere, lateral aspect; b. Left paramere, lateral aspect; c. Median lobe, left lateral aspect; d. Median lobe, ventral aspect; scale line = 1.0 mm.

FIGURE 40. Photographs of habitats for broscine species in the Gaoligong Shan region. a. SW slope of Kawakarpu Shan on slope NE of Chukuai Lake, 3950 m, 27.982°/098.480°, Bingzhongluo Township, Gongshan County, Yunnan (habitat for Brosocodera chukuai sp. nov.); b. Second cirque S of Shibali Yakou at border post “31”, 3710 m, 27.203°/098.693°, Lumadeng Township, Fugong County, Yunnan (habitat for Brosocodera chukuai sp. nov., Broscosoma furvum sp. nov., and Broscosoma viridicollare sp. nov.). Photos by David H. Kavanaugh.

FIGURE 48. Chart showing the representation of broscine species in project-designated Core Areas (see Fig. 3) in the Gaoligong Shan region.

FIGURE 49. Chart illustrating the altitudinal ranges of broscine species represented in the Gaoligong Shan region. Green bars mark the elevational range recorded for each species.

FIGURE 50. Chart illustrating the co-occurence (syntopy) of broscine species in samples from the same habitats and at the same sites in the Gaoligong Shan region. Incidents of syntopy marked in black represent confirmed co-occurrence, those marked in grey not confirmed by records but likely.

FIGURE 2–4. Fig. 2. Map showing natural extent of study area, colored in green (however, sampling was permitted only in those portions in Yunnan Province. Fig. 3. Map showing location of core sampling areas. Fig. 4. Map showing locations of all entomological sampling sites. Scale lines = 100 km.