Leaf-cutting bees

Definition

Bees in the family Megachilidae, primarily the genus Megachile and related genera (e.g., Anthidium, Coelioxys), that cut circular or oval pieces from leaves or petals to line nest cavities and construct brood cells. Unlike most bees, females carry pollen on scopal hairs beneath the abdomen (ventral scopa) rather than on the hind legs. The leaf pieces are layered to form thimble-shaped cell walls, each provisioned with pollen and nectar and sealed with a circular leaf cap. Native to most continents; important solitary pollinators of wildflowers and crops including alfalfa, blueberries, and onions.

Etymology

From the distinctive behavior of excising leaf fragments with the mandibles; 'Megachile' derives from Greek megas (large) + cheilos (lip), referring to the large cutting mandibles.

Example

Megachile rotundata, the alfalfa leafcutting bee, is managed commercially in North America for alfalfa pollination; females cut ~75 leaf discs per nest, preferring leaves with smooth cuticles such as alfalfa, rose, or lilac.

Synonyms

• leafcutter bees
• megachilid bees

Related Terms

• Megachilidae
• ventral scopa
• brood cell
• solitary bee
• cuckoo bee
• Pollen basket
• nest provisioning
• Alfalfa leafcutting bee

Usage Notes

Distinguished from 'carder bees' (Anthidium), which scrape plant hairs rather than cut leaves, and from 'mason bees' (Osmia), which use mud or chewed leaf pulp. The common name applies to behavior, not a formal taxon; not all Megachilidae are leaf-cutters (some use resin, mud, or plant hairs). In management contexts, 'leafcutting bee' (no hyphen) is often preferred.