Campanula-pollinator
Guides
Chelostoma
Scissor Bees
Chelostoma is a genus of solitary bees in the tribe Osmiini (family Megachilidae), comprising approximately 56-60 described species across five subgenera. These bees are predominantly Palaearctic in distribution and are notable for their high degree of pollen specialization: most species are strict oligoleges, collecting pollen from flowers of a single plant genus, subfamily, or family. Common host plant associations include Campanula (bellflowers), Ornithogalum, Ranunculus, Asteraceae, and Brassicaceae. Nesting occurs in preexisting cavities in dead wood or hollow plant stems, with females constructing brood cell partitions and nest plugs using mud often reinforced with pebbles and sand grains.