Broscosoma gongshanense 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 : 124-127

7. Broscosoma gongshanense Kavanaugh and Liang , sp. nov.

Figures 7e , 22 , 23 , 42a , 48-50

Type material. Holotype, a male, in IOZ, labeled: “ CASENT 1026430 ”/ “ CHINA, Yunnan Province, Gongshan County, Cikai Township, 2.0 airkm S Heipu Yakou in cirque at head of Pula valley , 3350m ” / “ N27.75442º / E098.45639º, 12 August 2006, Stop #DHK2006-070, D.H. Kavanaugh, J. A. Miller collectors”/ “HOLOTYPE Broscosoma gongshanense Kavanaugh & Liang sp. nov. designated 2021” [red label] . Paratypes (a total of five): one male and two females ( CAS, IOZ) labeled: same as holotype except first label “ CASENT 1026439 ” and “ CASENT 1026439 ” to “ CASENT 1026439 ”, respectively; one male and one female ( CAS, IOZ) labeled: “ CASENT 1008139 ” and “ CASENT 1006244 ”, respectively/ “ CHINA, Yunnan Province, Gaoligong Shan, Nujiang Prefecture, Nujiang State Nature Reserve , Dulong / Gongshan Yakou area , 21 airkm W of Gongshan ” / “ N27.69655º / E098.45389º, 3300-3680m, 16-17 July 2000, Stop #00- 24C, D.H. Kavanaugh, C.E. Griswold, H.-B. Liang, D. Ubick & D.-Z. Dong collectors”. All paratypes also bear the following label: “PARATYPE Broscosoma gongshanense Kavanaugh & Liang , sp. nov. designated 2021” [yellow label].

Type locality. China, Yunnan Province, Gongshan County, Cikai Township, Heipu Yakou area.

Derivation of species name. The species epithet, gongshanense , is an adjective derived from the name of the county, Gongshan, in which all members of the type series were collected, and the Latin suffix, -ensis, denoting place.

Diagnosis. Adults of this species ( Fig. 22a ) can be distinguished from those of other species in the region by the following combination of character states: size moderate, BL = 9.5 to 9. 9 mm; head and pronotum black to piceous, without a trace of metallic reflection; head with tempora straight or only slightly convex behind eyes; genal ridge evident, extended from base of head to ventral margin of eye (as in Fig. 10a ); antennomeres 3 and 4 glabrous except for apical whorl of setae; pronotum anterior to sub-basal constriction slightly longitudinally ovoid in dorsal view ( Fig. 7e ), lateral margination absent or developed only posterior to sub-basal constriction, basolateral setae absent; elytral silhouette ovoid, with humeri indistinct, elytral microsculpture effaced; metatrochanter asetose; male protarsi with tarsomeres 1 to 3 with ventral pads of adhesive setae; male genitalia as in Fig. 23 .

Description. Fig. 22a . Size medium, BL male = 9.5–9. 8 mm, female = 9.5–9. 9 mm, ratio EL/PL male = 2.1, female = 2.2–2.3. Body color black or dark piceous, last visible abdominal sternite dark brown or rufous brown, antennae with antennomeres 3 and 4 black or piceous, antennomeres 1 and 2 and 5 to 11 rufous brown. Femora and tibiae piceous or dark brown, tarsi rufous brown. Head and pronotum without metallic reflection, elytra with distinct blue or greenish-blue metallic reflection, venter without metallic reflection.

Head. Fig. 7e . Eyes medium-sized, their diameter equal to or slightly greater than length of tempora. Frontal furrows deeply impressed, narrow, short, linear, distinctly divergent posteriorly, and extended posteriorly to middle of eyes, or medium length, arcuate, slightly convergent anteriorly and posteriorly, and extended posteriorly beyond middle of eyes, faintly rugulose, impunctate. Vertex with post-temporal transverse sulcus deep, sharply defined, moderately or sparsely and finely punctate. Tempora obliquely convex. Genal ridges distinctly present from posterior region of head to ventral margins of eyes. Clypeus with one pair of setae. Supraorbital setae present, one pair. Eustipes of maxilla with two setae, the dorsobasal seta distinctly more than half as long as ventrobasal seta. Mentum with tooth present, simple, paramedial region shallowly foveate, one pair of mental setae present. Glosal sclerite (ligula) with one pair of setae. Submentum with one or two pairs of setae. Gula without transverse grooves. Antennomeres 3 and 4 without pubescence, ratio A3/A5 = 1.1–1.2.

Pronotum. Fig. 7e . Globose anterior to sub-basal constriction with base distinctly pedunculate, widest at middle of discal region, ratio PL/PW = 1.2–1.3, disk markedly convex; apical margination absent, lateral margination present, narrow, delineated only on base; basal margination absent; anterior transverse impression absent or shallow and indistinct; median longitudinal impression distinct, but fine and shallowly impressed; posterior transverse impression deep, sharply delineated; anterior region smooth; pronotal base coarsely punctate and rugulose; one pair of midlateral pronotal setae present at mid-length of discal region; basolateral pronotal setae absent.

Elytra. Elytral silhouette ovoid, widest at middle, ratio EL/EW male = 1.4–1.5, female = 1.5– 1.6, greatest elevation above lateral margin (in lateral view) posterior to middle; humeri narrow, sloped, indistinct; lateral margins markedly arcuate or markedly arcuate and faintly angulate sub-basally; parascutellar striole present, short, distally merged in a distinct jog with free base of stria 1. Eight striae present; stria 1 moderately deeply and sharply impressed, striae 2 to 3, 4, or 5 moderately impressed in basal two-thirds of striae and successively more shallowly impressed in apical third, striae 2 to 8 successively more shallowly impressed laterally and apically, striae obliterated apical and laterally in some specimens, striae 8 merged with lateral groove throughout its length or nearly so; stria 1 coarsely and moderately densely punctate, striae 2 and 3 or 4 moderately to coarsely punctate in basal half and successively more shallowly and sparsely punctate in apical half, striae 4 or 5 to 8 successively more finely punctate or impunctate laterally and apically. Elytral microsculpture effaced. Parascutellar seta present at base of stria 2, discal setae absent, umbilicate series comprised of one post-humeral and two preapical setae.

Hindwings. Vestigial, incapable of supporting flight.

Thoracic venter. Metepisternum ratio ML/MW = 1.5–1.9.

Legs. Hind trochanter asetose. Tarsomeres without dorsal pubescence; tarsomere 5 with two or more pairs of setae ventrally; male protarsi with pads of adhesive setae on tarsomeres 1 to 3 ventrally, male mesotarsi with pads of adhesive setae on tarsomeres 1 and 2 ventrally.

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

Male genitalia. As in Fig. 23 .

Comments. As noted in the Comments section for B. bicoloratum , this is one of four species in the study area members of which have the elytra with distinct metallic reflection but the forebody (head and pronotum) without metallic reflection or with that reflection confined to the pronotal area anterior to the anterior transverse impression. Its members can be distinguished from those of B. viridicollare in having smaller body size, the eyes less convex and tempora straight or faintly convex (distinctly convex, subangulate B. viridicollare ), the pronotum without a trace of metallic reflection (band of metallic green reflection present anterior to anterior transverse impression B. viridicollare ), the elytral microsculpture effaced (finely but distinctly impressed in B. viridicollare ), and the median lobe of the male genitalia shorter and more evenly arcuate. They differ from members of B. bicoloratum in having the eyes less convex, the tempora shorter and nearly straight (tempora longer and distinctly more convex in B. bicoloratum ), and the discal portion of the pronotum very slightly more elongate (more globose B. bicoloratum ). They differ from members of B. gaoligongense in having the tempora slightly less convex, the parascutellar seta inserted near the base of stria 2 (stria 3 in most B. gaoligongense ), the metatrochanter asetose (unisetose B. gongshanense ), and the median lobe of the male genitalia relatively shorter and with sclerites of the internal sac of different shapes.

As noted above in the Comments sections for B. bicoloratum and B. gaoligongense , among Broscosoma species known from outside the study area, only B. monticola has members of similar size and with the forebody lacking metallic reflection and the elytral with markedly metallic reflection as is seen in B. gongshanense specimens. However, they have the parascutellar seta inserted near the base of stria 3 (stria 2 in B. gongshanense ), the femora slightly paler, and the median lobe of the male genitalia with a large protuberance on the ventral margin (see Habu 1973, fig. 6), which is absent from the median lobe of B. gongshanense males.

Habitat distribution. Members of this species have been found under stones along trails through bamboo and Rhododendron thickets and in moist alpine meadow areas ( Fig. 42a ) at or near the crest of the range. Our records document occurrence of this species at moderately high elevations in the 3350 to 3680 m range ( Fig. 49 ).

Geographical distribution within the Gaoligong Shan. Fig. 22b . We examined a total of six specimens (three males and three females), all from at or near the crest of the range in Gongshan County. We recorded this species only from the crest and adjacent slopes to the east in Core Area 2 ( Fig. 48 ), but it probably also occurs on the western side at equivalent elevations in Core Area 1 .

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

Geographical relationships with other Broscosoma species. Members of this species have been found together only with those of Broscosoma bicoloratum at one or more sites ( Fig. 50 ). Broscosoma ribbei occurs in the same general area but mainly at lower elevations.

Figures

FIGURE 7. Forebody, Broscosoma species, dorsal aspect. a. B. furvum sp. nov. (CASENT1020001; first cirque S of Shibali Yakou, Fugong County, Yunnan, China); b. B. viridicollare sp. nov. (CASENT1022787; 8.5 km above Shibali, Lishadi Twonship, Fugong County, Yunnan, China); c. B. bicoloratum sp. nov. (CASENT1026704; slope NW of Heipu Yakou, Dulongjiang Townhip, Gongshan County, Yunnan, China); d. B. gaoligongense Deuve and Wrase (CASENT1027285; just W of Fenxue Yakou, Pianma Township, County, Yunnan, China); e. B. gongshanense sp. nov. (CASENT1008139; Dongshaofang area, Gongshan County, Yunnan, China).

FIGURE 22. Broscosoma gongshanense sp. nov. a. Habitus (CASENT1008139; Dongshaofang area, 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 23. Male genitalia, Broscosoma gongshanense sp. nov. (CASENT1026429; 2.0 km S of Heipu Yakou, Cikai Township, Gongshan County, Yunnan, China). a. Right paramere, lateral aspect; b. Left paramere, lateral aspect; c. Medi- an lobe, left lateral aspect; d. Median lobe, ventral aspect; scale line = 1.0 mm.

FIGURE 42. Photographs of habitats for Broscosoma species in the Gaoligong Shan region. a. Dulong/Gongshan Yakou area, 3300-3680m, 27.697º/098.454º, Gongshan County, Yunnan (habitat for Broscosoma bicoloratum sp. nov. and B. gongshanense sp. nov.); b. Southeastern slope of Heipu Yakou, 3365m, 27.770º/098.447º, Cikai Township, Gongshan County, Yunnan (habitat for Broscosoma bicoloratum 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 10. Head, Broscosoma species, lateral aspect. a. B. furvum sp. nov. (CASENT1020001; first cirque S of Shibali Yakou, Fugong County, Yunnan, China); b. B. gaoligongense Deuve and Wrase (CASENT1027285; just W of Fenxue Yakou, Pianma Township, County, Yunnan, China); c. B. purpureum sp. nov. (CASENT1015871; Moqie Wang, Dulongjiang Township, Gongshan Yunnan, China). White arrows denote endpoints of genal ridge.