August, 2015

Leaf-cutter Bee

Many bees collect pollen to feed their young, and most store it on their legs in order to transport it back to the nest. The familiar honey and bumble bees have a smooth depression in their hind legs, called a corbicula, for this purpose, but other bees use a scopa: a cluster of special hairs that hold the pollen grains. While most families of bees have the scopa on the hind legs, the leaf-cutter bee (Megachile sp.) shown above, as well as other members of the family Megachilidae, have the scopa on their belly instead.

Leaf-cutter bees use their jaws to cut round sections out of leaves and flower petals, but they do not eat this or feed it to their young. Instead, the plant material is used to line their nest, sort of like wallpaper. Nests are usually in soft wood or stems, but can also be under rocks and other suitable crevices. The overlapping bits of leaves form a barrier that keeps out unwanted moisture and microbes that might spoil the stored pollen.