Native Bee Diversity: Leafcutter Bees

Early in the fall, I was delighted to find this fallen redbud leaf with this unusual, sculpted edge. This leaf is evidence of bee activity much earlier in the year. This is the work of female leafcutter bees (Megachile spp.) who cut out leaf semi-circles with their strong mandibles. Each leaf piece becomes a nursery for a single egg provisioned with a pollen loaf. Leafcutter bees often nest in hollow stems and other cavities, sometimes in the ground. Unlike other bees who store pollen on their legs, leafcutter bees carry it on the undersides of their abdomens. These are solitary bees, so each nest is typically individually situated, and the bees are generally gentle and non-aggressive.

Leafcutter bees are excellent pollinators since they move vigorously through flowers, dislodging pollen as they barrel through the stamens. When they emerge early in the spring, they visit wildflowers, fruits and vegetables. Commercial growers use them to pollinate some crops, including blueberries, onions and more.

There are over 4000 species of native bees in North America, of which 242 are leafcutter bees.

For more information, see HGIC 1733, Native Pollinators.