Staphylinoidea (Insecta: Coleoptera) is one of the most species-rich groups in animals, but its huge diversity can hardly be explained by the popular hypothesis (co-radiation with angiosperms) that applies to phytophagous beetles. We estimated the evolutionary mode of staphylinoid beetles and investigated the relationship between the evolutionary mode and palaeoclimate change, and thus the factors underlying the current biodiversity pattern of staphylinoid beetles. Our results demonstrate that staphylinoid beetles originated at around the Triassic-Jurassic bound and the current higher-level clades underwent rapid evolution (indicated by increased diversification rate and decreased body size disparity) in the Jurassic and in the Cenozoic, both with low-energy climate, and they evolved much slower during the Cretaceous with high-energy climate. Climate factors, especially low O₂ and high CO₂, promoted the diversification rate and among-clade body size disparification in the Jurassic. In the Cenozoic, however, climate factors had negative associations with diversification rate but little with body size disparification. Our present study does not support the explosion of staphylinoid beetles as a direct outcome of the Cretaceous Terrestrial Revolution (KTR). We suppose that occupying and diversifying in refuge niches associated with litter may explain rapid radiations of staphylinoid beetles in low-energy conditions.

A new subgenus Wraseiellus new subgenus (type species: Pterostichus andrewesi Jedlička 1931) of the genus Pterosti-chus from China is described. Eight species and one subspecies are recognized in the new subgenus including three new species and one new subspecies: Pt. (Wraseiellus) comatus new species (Guangxi: Maoershan, N25.87º, E110.42º), Pt. (Wraseiellus) crassiapex new species (Hubei: Tiechanghuang, N30.75º, E110.30º), Pt. (Wraseiellus) pseduodiversus new species (Yunnan: Luguhu, N27.63º, E100.82º), Pt. (Wraseiellus) stictopleurus cangshanensis new subspecies (Yunnan: Cangshan, N25.63º, E100.14º). Feronia crebrepunctata Straneo, 1937 is newly proposed as junior synonym of Pterosti-chus meyeri Jedlička, 1934. A key to all known species and subspecies, images of habitus and genitalia, and distribution maps are provided.

We report on the species richness patterns of epigaeic beetles (Coleoptera: Carabidae and Staphylinidae) along a subtropical elevational gradient of Balang Mountain, southwestern China. We tested the roles of environmental factors (e.g. temperature, area and litter cover) and direct biotic interactions (e.g. foods and antagonists) that shape elevational diversity gradients. Beetles were sampled at 19 sites using pitfall traps along the studied elevational gradient ranging from 1500 m–4000 m during the 2004 growing season. A total of 74416 specimens representing 260 species were recorded. Species richness of epigaeic beetles and two families showed unimodal patterns along the elevational gradient, peaking at mid-elevations (c. 2535 m), and the ranges of most beetle species were narrow along the gradient. The potential correlates of both species richness and environmental variables were examined using linear and second order polynomial regressions. The results showed that temperature, area and litter cover had strong explanatory power of beetle species richness for nearly all richness patterns, of beetles as a whole and of Carabidae and Staphylinidae, but the density of antagonists was associated with species richness of Carabidae only. Multiple regression analyses suggested that the three environmental factors combined contributed most to richness patterns for most taxa. The results suggest that environmental factors associated with temperature, area and habitat heterogeneity could account for most variation in richness pattern of epigaeic beetles. Additionally, the mid-elevation peaks and the small range size of most species indicate that conservation efforts should give attention to the entire gradient rather than just mid-elevations.