Inventory of the Carabid Beetle Fauna of the Gaoligong Mountains, Western Yunnan Province, China: Species of the Tribe Broscini (Coleoptera: Carabidae).
Author
Kavanaugh, David H.
Department of Entomology, California Academy of Sciences, 55 Music Concourse Drive, Golden Gate Park, San Francisco, CA 94118, U. S. A.
Author
Liang, Hongbin
Key Laboratory of Zoological Systematics, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
text
Proceedings of the California Academy of Sciences
2021
2021-09-30
67
4
85
182
journal article
299055
10.5281/zenodo.11067355
67ec2de4-1816-4969-8132-f6796d3afa06
0068-547X
11067355
Genus
Broscosoma
Rosenhauer, 1846
Broscosoma
Rosenhauer, 1846:1
.
Type
species:
Broscosoma baldense
Rosenhauer, 1846:4
.
Diagnosis.
Members of this genus can be distinguished from those of other broscine genera in the region by the following combination of character states: body small to moderate in size (BL>13.0 mm); body surface with or without metallic reflection; head with post-temporal transverse sulcus moderately deep and broadly or narrowly punctate; genal ridge present, but varied in extent; maxillae with two setae on eustipes, stipes with dorsobasal setae at least half as long as ventrobasal setae; mentum with one pair of setae present, paramedial region moderately to deeply foveate; submentum with one to three pairs of setae; antennae with antennomeres 3 and 4 glabrous except for apical whorl of fixed setae; pronotum with basolateral setae absent; elytra with parascutellar seta present, umbilicate setal series comprised of one post-humeral and two preapical setae; male protarsi with pads on adhesive setae ventrally on tarsomeres 1 to 3, and mesotarsi with pads of adhesive setae on tarsomeres 1 and 2.
Taxonomic notes.
The generic diagnosis presented above properly applies only among those species occurring in the study area. Members of some species of the genus occurring elsewhere present exceptions to several of the character states listed. Even the features most widely applied as characteristic of the genus are subject to exceptions, including among species of the study area.
Roig-Juñent (2000)
distinguished
Broscosoma
species
from
Miscodera arctica
(Paykull), 1798
principally on differences in the lateral margination of the pronotum (present in
Miscodera
and absent from
Broscosoma
) and paramedial foveae on the mentum (present in
Miscodera
and absent from
Broscosoma
). However, we have found lateral margination of the pronotum present in at least some form (
Figs. 9
a-d) in several of the species occurring in the study area and fully present in members of one species. Similarly, we have found that members of most
Broscodera
species
in the study area have at least shallow paramedial foveae on the mentum, and one species has foveae comparably deep to those of
M. arctica
members. Other features listed by Roig-Juñent in his description of the genus are also subject to greater variation among
Broscosoma
species
in the study area than was represented in his sample of only three species. Among these are development of the genal (or “temporal”) ridge (
Figs. 10
a-d), number of pairs of setae on the submentum, and pubescence on antennomere 4.
Since
Sciaky and Facchini (2005)
presented their excellent key to the
Broscosoma
species
of
China
, the number of species known from that country has more than tripled, from eight to 26, not including any of the species newly described herein. Clearly, a new key to Chinese species is needed; but new species continue to be discovered (see
Jiang et al. 2020
and
Jiang et al. 2021
for the most recent additions) at such a rate as to make creating such a key a rapidly ‘moving target’, which we plan to attempt, nonetheless, in the near future.
Diversity and geographical distribution.
To date, 43 species and an additional five subspecies of
Broscosoma
have been described. The genus is strictly Palearctic in distribution, with a range extended from the Alps of northern
Italy
eastward to
Japan
and
Taiwan
, but with wide disjunctions apparent. The main distributional gaps occur between (1) northern
Italy
and the Caucasus Mountains, (2) the Caucasus and the Himalaya in central
Nepal
, and (3) Chongqing and Shaanxi Provinces and Fujian Province,
Taiwan
, and
Japan
.