The bumblebees of Sichuan (Hymenoptera: Apidae, Bombini)

Abstract

Bumblebees are important pollinators in mountainous regions. The highland region of Sichuan and Chongqing (together, Sichuan in the former broad sense) includes part of the greatest hotspot of bumblebee diversity worldwide, with half of the species of China and more than a fifth of the world's species. In this paper we present the first review of this diverse but particularly poorly known fauna, drawing on 6705 bees from selective samples made by the authors during field work and from museum collections, together with 1123 literature records (an overlapping set). Among this material we recognise 56 species that have 847 names (including infrasubspecific names). One new species, Bombus (Pyrobombus) wangae, is described from Sichuan and Gansu. B. laesus is found to have a colour pattern in this part of its range that was previously undescribed. Six species are recorded from the Sichuan‐Chongqing region for the first time (B. avanus, B. branickii, B. difficillimus B. humilis, B. norvegicus, B. tibetanus), of which B. avanus is only the second published record worldwide. One species, B. braccatus, is endemic to Sichuan and is confirmed as extant in 2005. We provide diagnoses and keys to species for both sexes. Colour variation is described, distributions within the Sichuan‐Chongqing region are mapped, altitudinal and seasonal activity are plotted, and the authors’ records of food plants are listed.