Leafcutter Bee
Megachile
Heather Holm
Summary
Alert gardeners sometimes find perfectly semi-circular holes in the leaves of trees and shrubs, leading them to wonder, “What’s eating my plant, and how can I get rid of it?” But these holes aren’t the mark of a sinister pest–quite the opposite! They’re more likely the unmistakable sign of a leafcutter bee.
Most leafcutter bees are similar in size to honey bees, slightly darker in color and with light bands on the abdomen. Their habits, however, are totally different! Leafcutter bees are solitary bees, and don’t form colonies that must be protected This means that they’re not aggressive, and sting only when handled.
Female leafcutter bees do all the work of rearing their young, digging out nesting areas, creating nest cells and providing food. When constructing a nest, leafcutter bees collect fragments of leaves to construct individual cells within the nest. The bees cut leaves in a distinctive manner, making a smooth semicircular, or crescent moon shape, cut about 3/4 inch in diameter from the edge of leaves. Although they cut many types of leaves, redbud, rose and Virginia creeper are some favorites.
More Details
FAMILY
Megachilidae
LIFE CYCLE NOTES
Nesting cavities can be found above ground in pithy plant stems, or holes in snags. Leafcutter bees usually have one generation per year. Most leafcutter bees overwinter as prepupae, and finish their development the following spring, emerging as adults in late spring or summer. Noteworthy large mandibles with sharp teeth used to cut leaves or petals for nesting materials.
FORAGING NOTES
Females with rows of pollen-collecting hairs on the underside of abdomen.
SOCIALITY
Solitary
Ecosystem Connections
Most bees carry pollen in baskets on their legs. However, Megachile is different: The underside of the female’s abdomen is particularly furry, so leafcutter bees use their bellies to transport pollen. These efficient generalists pollinate a wide variety of flowers and crops, from alfalfa to blueberries to sunflowers.