If you’ve ever noticed nearly perfect ovals, circles or semicircles cut out of leaves (and even flowers), you might have some leafcutter bees nearby. These small bees readily inhabit “bee hotels” and other natural tunnels in wood or in the ground. They construct a number of individual cells in each tunnel that are made from the leaf pieces they collect. Each cell will contain a single egg and a store of pollen to feed the emerging larva. Since each female is on her own (they do not work together as a colony), they are incredibly busy, making many, many trips back and forth with pieces of leaves and pollen.
Unlike other bee species that collect pollen in pollen baskets on their legs, leafcutters collect pollen in a dense mass of hairs on the underside of their abdomen (called scopa) …turning their bellies yellow as they collect.
Size: Typically 7 – 9 mm, a few to 12 mm or larger
Photo by: Glenn Marangelo on 7/9/22 in Missoula, MT