Broscosoma danzhuense 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 : 113-116

4. Broscosoma danzhuense Kavanaugh and Liang , sp. nov.

Figures 6e , 17 , 43 , 48-50

Type material. Holotype, a female, in IOZ, labeled: “ CASENT 1004637”/ “ CHINA, Yunnan Province, Gaoligong Shan, Nujiang Prefecture , Gongshan County, Danzhu He drainage , 13.5-13.8 airkm SSW of Gongshan [Cikai], 2720-2840 m,”/ “N27.63267°/E98.60861° to”/ “N27.63331°/E98.60356°, 30 June – 5 July 2000, Stop#00-17E, D.H. Kavanaugh, C.E. Groswold [sic], Liang H.-B., D. Ubick, & Dong D.-Z. Collectors ”./ “HOLOTYPE Broscosoma danzhuense Kavanaugh & Liang sp. nov. designated 2021” [red label].

Type locality. China, Yunnan, Gongshan County, Cikai Township, Danzhu He drainage 2720- 2840 m.

Derivation of species name. The species epithet, danzhuense , is derived from the name of the river valley in which the type specimen was collected, and the Latin suffix, -ensis, denoting place.

Diagnosis. Adults of this species ( Fig. 17a ) can be distinguished from those of other species in the region by the following combination of character states: size moderate, BL female = 9.3 mm; entire dorsum of body dark green, legs with femora darker (brown to piceous) than tibiae (reddish-brown); antennomeres 3 and 4 glabrous except for apical whorl of setae; eyes ( Fig. 6e ) moderately convex; pronotum with lateral margination absent, basolateral setae absent; elytral silhouette subovoid, greatest width distinctly posterior to midlength, with humeri rounded yet slightly evident, elytral microsculpture faintly impressed but evident, only striae 1 impressed, all other elytral striae represented only be punctures diminishing in size and depth laterally and posteriorly, elytral intervals flat; metatrochanters asetose.

Description. Fig. 17a . Size medium, BL female = 9.3 mm, ratio EL/PL = 2.3. Body color piceous. Last visible abdominal sternite dark or rufous brown, antennae with all antennomeres rufous brown, femora brown or piceous, tibiae and tarsi reddish brown. Head, Pronotum, elytra with distinct green metallic reflection, venter without metallic reflection.

Head. Fig. 6e . Eyes small, their diameter slightly less than length of tempora. Frontal furrows deeply impressed, narrow, arcuate, slightly convergent anteriorly and posteriorly, long, extended posteriorly beyond middle of eyes, faintly rugulose, impunctate. Vertex with post-temporal transverse sulcus deep, sharply and narrowly defined, narrowly punctulate only along bottom of sulcus. Tempora nearly straight, subparallel. Genal ridges present, restricted to head region distinctly behind post-temporal constriction. 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 two or three pairs of setae. Gula without transverse grooves. Antennomeres 3 and 4 without pubescence, ratio A3/A5 = 1.3.

Pronotum. Fig. 6e . Discal region anterior to sub-basal constriction slightly longitudinally ovoid, slightly narrowed anteriorly with base distinctly pedunculate, widest slightly posterior to middle of discal region, ratio PL/PW = 1.2, disk markedly convex; apical, lateral, and basal margination absent; anterior transverse impression shallow, narrowly delineated, punctate in bottom of impression only; median longitudinal impression distinct, but fine and shallowly impressed; posterior transverse impression deep, sharply delineated; anterior region smooth; pronotal base coarsely and densely punctate; one pair of midlateral pronotal setae present, inserted slightly anterior to mid-length of discal region; basolateral pronotal setae absent.

Elytra. Elytral silhouette subovoid, slightly narrowed in basal half, widest distinctly posterior to middle, ratio EL/EW = 1.6, greatest elevation above lateral margin (in lateral view) posterior to middle; humeri distinctly present, roundly obtuse; lateral margins moderately arcuate and nearly straight in anterior half sub-basally; parascutellar striole present, short, distally merged in a distinct jog with free base of stria 1. Eight elytral striae present; stria 1 moderately deeply and sharply impressed, striae 2 to 8 indistinct, obliterated or represented by extremely fine and shallow linear depressions, successively less evident laterally and apically, striae 8 merged with lateral groove throughout its length or nearly so; stria 1 moderately punctate at least in basal half, striae 2 to 8 successively more finely and sparsely punctate or impunctate laterally and apically. Elytral microsculpture effaced. Parascutellar seta at base of stria 2, discal setae absent, umbilicate series comprised of one post-humeral and two preapical setae.

Hindwings. Slightly reduced, incapable of supporting flight.

Thoracic venter. Metepisternum ratio ML/MW = 2.4.

Legs. Hind trochanter asetose. Tarsomeres without dorsal pubescence; tarsomere 5 with two or more pairs of setae ventrally.

Abdomen. Female sternite VI with one pair of apicoparamedial setae.

Male genitalia. Male unknown.

Comments. This is one of six species in the study area members of which have the elytral humeri rounded or slightly angulate but distinct and both the forebody and the elytra with distinct metallic reflection. In two of these, B. holomarginatum and B. purpureum , the reflection is mainly blue or purple in color, respectively, with some greenish tinges in most specimens of B. holomarginatum . In addition to B. danzhuens e, three species have the full dorsum of the body with green metallic reflection. Broscosoma parvum members are smaller in size, have eyes that are less convex ( Fig. 6f ), and have the elytral silhouette slightly narrower across the humeri and the greatest width at or very near midlength (distinctly posterior to midlength in B. danzhuense ). Broscosoma resbecqi members have the pronotum with the discal portion relatively shorter and more globose ( Fig. 6d ) and lateral margination present and nearly complete, interrupted only briefly near basal two-thirds length ( Fig. 9b ) (absent from B. danzhuense ), the elytra with their greatest width at or very near midlength, and femora pale rufous (darker in B. danzhuense ). Broscosoma ribbei members have the eyes distinctly more convex, the post-temporal transverse sulcus not or more sparsely punctate, the pronotum with the discal portion relatively shorter and more globose ( Fig. 6b ) and lateral margination incomplete but present in most specimens, at least in the vicinity of the midlateral setae and more extensively in some specimens, elytral microsculpture distinct, deeply to moderately impressed (effaced in B. danzhuense ), and the metatrochanters unisetose, unilaterally asetose in a few specimens (asetose in B. danzhuense ).

Among Broscosoma species known from outside the study area, only two species, Broscosoma montreuili Deuve, 2006 and Broscosoma tiani Deuve, 2006 have members in which the elytral humeri are at least faintly evident (although in both they are less evident than in B. danzhuense ) and the entire dorsum exhibits metallic green reflection. In members of B. montreuili , the forebody is a darker, less vividly metallic green than the elytra (both parts equally vivid in B. danzhuense ), and in both B. montreuili and B. tiani members the discal portion of the pronotum is more globose (slightly narrower and more elongate in B. danzhuense ), the elytra are widest at or near midlength and with striae 2 to 8 more faintly defined and finely punctate, and the femora are darker (lighter piceous or brown in B. danzhuense ).

Habitat distribution. The unique specimen of this species was found under a stone at the edge of a moderate-sized cascading stream descending through mixed coniferous/ broadleaf evergreen forest and shaded during much of the day. The site of collection was at some point within the moderate elevational range of 2720 to 2840 m ( Fig. 49 ), but the precise elevation was not recorded.

Geographical distribution within the Gaoligong Shan. Fig. 17b . This species is known only from the type locality in Gongshan County (see Type material above for exact collection data) on the eastern slope of the range in the southern part of Core Area 2 ( Fig. 48 ).

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

Geographical relationships with other Broscosoma species. No other Broscosoma species was found syntopic with the type of this species, although B. ribbei occurs in the same general area. Eobroscus bhutanensis also has been found in the same area and habitat as B. danzhuense ( Fig. 50 ).

Figures

FIGURE 6. Forebody, Broscosoma species, dorsal aspect. a. B. holomarginatum sp. nov. (CASENT1015162; 0.5 km N of Kongdang, Dulongjiang Township, Gongshan County, Yunnan, China); b. B. ribbei Putzeys (CASENT1025337; 0.5 km WSW of Maku village, Dulongjiang Township, Gongshan County, Yunnan, China); c. B. purpureum sp. nov. (CASENT1015338; 0.5 km N of Kongdang, Dulongjiang Township, Gongshan County, Yunnan, China); d. B. resbecqi sp. nov. (Holotype; Siran Wang, Dulongjiang Township, Gongshan County, Yunnan, China); e. B. danzhuense sp. nov. (Holotype; Danzhum He drainage, Cikai Township, Gongshan County, Yunnan, China); f. B. parvum sp. nov. (CASENT1023565; 11.5 km above Shibali, Lishadi Township, Fugong County, Yunnan, China).

FIGURE 17. Broscosoma danzhuense sp. nov. a. Habitus (Holotype; Danzhum He drainage, Cikai Township, 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 43. Photographs of habitat for broscine species in the Gaoligong Shan region; a. Danzhu He drainage, 2840 m, 27.633°/98.604°, Cikai Township, Gongshan County, Yunnan (habitat for Broscosoma danzhuense sp. nov. and Eobroscus bhtanensis Morvan). Photo 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 9. Prothorax, Broscosoma species, oblique left lateral aspect. a. a. B. holomarginatum sp. nov. (CASENT1016746; 0.5 km N of Kongdang, Dulongjiang Township, Gongshan County, Yunnan, China); b. B. resbecqi sp. nov. (Holotype; Siran Wang, Dulongjiang Township, Gongshan County, Yunnan, China); c. B. ribbei Putzeys (CASENT1025337; 0.5 km WSW of Maku village, Dulongjiang Township, Gongshan County, Yunnan, China); d. B. purpureum sp. nov. (CASENT1015871; Moqie Wang, Dulongjiang Township, Gongshan Yunnan, China). White arrows denote end points of lateral margination.