Megabombus bumblebees have unusually long tongues and are generally more specialised than other bumblebees in their choice of food plants. The phylogeny of Megabombus bumblebees shows that speciation was concentrated in two periods. Speciation in the first period (ca 4.25-1.5 Ma) is associated with the late rise of the Hengduan Mountains at the eastern end of the Qinghai-Tibetan plateau. Specia...

Social bees and other insects are frequently parasitized by a large range of different microorganisms. Among these is Crithidia bombi (Kinetoplastida: Trypanosomatidae), a common gut parasite of bumblebees, Bombus spp. (Insecta: Apidae). Bumblebees are important pollinators in commercial and natural environments. There are clear detrimental effects of C. bombi infections on the fitness of bumbl...

Bumblebees (Apidae: Bombus spp.) are a major group of wild and domesticated bees that provide crucial ecosystem services through wildflower crop pollination. However, most bee populations, including bumblebees, declining worldwide, partly because parasite spill-over spill-back between bumblebee commercial colonies populations. Breeders have to cope with invasions by vast array bumblebees’ paras...

A MiSeq multiplexed 16S rRNA amplicon sequencing of the gut microbiota of wild and indoor-reared Bombus terrestris (bumblebees) confirmed the presence of a core set of bacteria, which consisted of Neisseriaceae (Snodgrassella), Orbaceae (Gilliamella), Lactobacillaceae (Lactobacillus), and Bifidobacteriaceae (Bifidobacterium). In wild B. terrestris we detected several non-core bacteria having a ...

Bumblebees are important pollinators for wild flowers and agricultural crops. North China is a region of varied geomorphology and vegetation, with plateaus, plains, mountains and deserts, and is part of the greatest hotspot of bumblebee diversity worldwide. We report on a field survey of the bumblebees of North China made between 2005-2012. A sample of 21,636 bumblebee specimens are assigned to...

Our understanding of how variable wind in natural environments affects flying insects is limited because most studies of insect flight are conducted in either smooth flow or still air conditions. Here, we investigate the effects of structured, unsteady flow (the von Karman vortex street behind a cylinder) on the flight performance of bumblebees (Bombus impatiens). Bumblebees are 'all-weather' f...

Within a particular animal taxon, larger bodied species generally have larger brains. Increased brain size usually correlates with increased behavioral repertoires and often with superior cognitive abilities. Bumblebees are eusocial insects that show pronounced size polymorphism among workers, whereas in honey bees size variation is much less pronounced. Recent studies suggest that within a giv...

Heterostyly is a floral polymorphism characterized by reciprocal herkogamy maintained through high levels of mating between morphs, serviced by appropriate pollinators. We studied how differential efficiency and abundance of distinct pollinators affect plant female reproduction in self- and intra-morph incompatible distylous Primula secundiflora. Bumblebees and syrphid flies were found to be th...

Mechanisms of spatial attention are used when the amount of gathered information exceeds processing capacity. Such mechanisms have been proposed in bees, but have not yet been experimentally demonstrated. We provide evidence that selective attention influences the foraging performance of two social bee species, the honeybee Apis mellifera and the bumblebee Bombus terrestris. Visual search tasks...

Several species of bumblebees have recently experienced range contractions and possible extinctions. While threats to bees are numerous, few analyses have attempted to understand the relative importance of multiple stressors. Such analyses are critical for prioritizing conservation strategies. Here, we describe a landscape analysis of factors predicted to cause bumblebee declines in the USA. We...