Leafcutter Bees
Megachile spp.

Leafcutter bees are solitary bees that are critical pollinators and leave distinct circle cutouts on the leaves they cut to build their nests.

This section shows one large critter image at a time. Use the thumbnails that follow to select a specific image to display here.

A female Megachile texana. (Photo courtesy of U.S. Geological Survey Bee Inventory and Monitoring Lab)

This gallery contains a grid of small thumbnails. Selecting a thumbnail will change the main image in the preceding section.

Appearance

Leafcutter bees are the same size as a common honey bee, but are slightly darker and have light tan stripes on their abdomen. Male leafcutter bees are smaller than females and have a rounder abdomen and longer antennae.

They have sharp mandibles (jaws) that can cut leaves and flowers to make their nests. Female bees have scopa (pollen collecting hairs) that pick up pollen on their abdomen while most other bees normally carry pollen on their legs. Males do not have scopa and do not transport pollen.

Feeding

Leafcutter bees take pollen and nectar from many types of wildflowers and will cut circles from almost any broadleaf plant to create their nest. Common plants they cut are ornamental plants such as roses, azaleas, and ash.

Predators

Parasitoid wasps, flies and beetles as well as ants can attack leafcutter bee nests.

Flight

Leafcutter bees stay close to their nests and don’t normally fly further than 300 feet once they have established a nesting location.

Reproduction and Life Cycle

Leafcutter bees are solitary unlike honey bees and wasps that produce colonies. The female leafcutter bee digs a nesting site, creates cells in the nest and provides the young with food. The male bee dies shortly after it mates with the female.

Leafcutter bees make nests in rotted wood and plants with pithy stems. Once the nesting site has been dug into a tunnel that is several inches deep, nest cells are made with a wide variety of leaf types such as rose, green ash, lilac and Virginia creeper. The leafcutter bee cuts a distinctive circular shape, but these cuts do not cause much harm to the plants.

The nest cells, once lined with leaves, are filled with nectar and pollen. An egg is then deposited into each nest cell and the female closes the nest with more leaves. The young bees develop and emerge from the cell the next season. Adult male and female bees emerge in the spring and mate.

Once the female bee makes a nest and seals in all the nest cells and the nest itself, the bee dies. The bees live approximately one year though humans only see the bee in its adult stage for 5-8 weeks in the summer.

Did You Know?

  • There are about 242 species of leafcutter bees that are native to North America.
  • Leafcutter bees are not aggressive and have a much less painful sting than other types of bees or wasps. They only sting if handled.
  • Some gardeners consider leafcutter bees to be a pest since the holes in plant leaves make the plants look unsightly, but little harm is done to the plant itself and these bees are important pollinators which benefits the plants.
  • One type of leaf cutter bee that is not native (Megachile rotundata) was intentionally introduced in parts of North America to pollinate alfalfa plants which the bees do very well.

Sources and Additional Information

Tags:
Insects Forests & Uplands