Bumblebees

Few stinging insects inspire as much warm affection as bumblebees. This group of social, furry, and colorful bees, all comprised within the genus Bombus Latreille, are among the most abundant pollinators in cold or temperate ecosystems, and act as key vectors for the pollination of both wild and cultivated flowering plants. The buzzing flight from flower to flower of these large, noisy insects never fails to capture the attention of children, nature lovers, and also professional entomologists. In his book The Effects of Cross & Self-Fertilisation in the Vegetable Kingdom, Charles Darwin himself made numerous observations on the intelligent floral visitation of "humble bees" (as they were called at the time), which led him to consider them as "...good botanists, for they know that varieties may differ widely in the colour of their flowers and yet belong to the same species". Further fascinated about bumblebee behaviour and their faculty to pierce holes in flowers for robbing nectar, he suggested, in a letter for the Gardner's Chronicle in 1841, "...that the practice of boring holes in [...] flowers is likewise a piece of acquired knowledge". The very tangible consequence of bumblebees' visibility today is their remarkable representation in entomological collections. Museums worldwide are filled with millions of pinned specimens, collected since the 18^th century, collectively serving as invaluable witnesses to how insect communities have changed over time. Bumblebees have become flagship species for insect conservation - especially conservation of pollinators - and have shaped our understanding of how current anthropogenic changes impact the animals upon which we depend for our well-being and the resilience of terrestrial ecosystems. In this Primer, we present a beginner's guide to the behavior, biogeography, conservation, ecology and evolution of these highly studied pollinators.