When we think of bees, honeybees or bumble bees usually come to mind. But did you know that there are 500 different species of bees native to Illinois? One of the coolest and most fun to watch is the leafcutter bee.
These bees are part of a family of bees called Megachilidae. In Latin, mega means “large” and chilidae means “lips.” These are “large-lipped” bees! Or rather, these bees have large jaws needed to do the work of being bees. Leafcutter bees need strong jaws to cut leaves. Besides leafcutter bees, this family includes mason bees, resin bees and carder bees.
These bees are small and gentle. Females are only about one-third of an inch long to a half-inch long, and the males are a little smaller. They only sting if they are provoked or if they get trapped in your clothing and get scared. Leafcutter bees are solitary — these are not hive bees — but they are also gregarious. Gregarious means that they are outgoing and like being near other bees.
Male leafcutters have very short lives. They only live as adults for two weeks, during which they mate with females and then die. Every female leafcutter bee is a queen and a soldier. She must create a nest on her own. This is why we call them solitary bees. She will find a hole in the ground, in a reed or in a tube to make a home for her eggs. Once she finds the perfect spot, she must make it comfortable.
She uses her strong jaws to cut perfect tiny circles from leaves, and then she hauls the leaf circle back to her nest. She lines the nest with these leaf pieces. Scientists think the leaves make it the perfect environment inside the nest, with just the right amount of humidity. Don’t worry. These holes made by the bees don’t seem to do any damage to the plant.
Next, she goes out and collects pollen. She stays close to home, never traveling much farther than the length of a football field away from home. She flies haphazardly from flower to flower, collecting pollen on the coarse hairs on her abdomen. Think of it like Velcro grabbing all the notorious yellow powder. If you see a bee with a powdery yellow abdomen, there’s a good chance it’s a Megachilidae bee.
Most other bees carry pollen securely in a sack on their thighs. This is why honeybees are not the best pollinators — they don’t drop much of their pollen. They only have a 5 percent pollination rate. Leafcutters and other Megachilidae bees end up dropping most of their pollen. Their pollination rate is 95 percent! They are great pollinators for melons, squash, peas, tomatoes, milkweed, sunflowers and other summer vegetables and flowers. This is why farmers are starting to keep leafcutters and other Megachilidae bees in their orchards.
Female leafcutter bees are still able to bring back enough pollen to their nests. She lays an egg on top of a pollen lump. This will provide lots of great food when the egg hatches. Then the female will cover the opening with more leaf circles to enclose the egg in its own room. She will continue doing this until the nest is full.
Like butterflies, leafcutter bees go through changes in their life cycle. They start out life as eggs in summer. Then they become larvae that look a little like white worms. They stay in this stage over the winter. They survive by doing the insect version of hibernation, called diapause. By spring, they reach the pupae stage and then finally transition into adult bees.
This is just in time to see these bees buzzing about in spring and summer — making their nests, cutting circles in leaves, pollinating and hanging out near other bees. Get outside to watch their activities. It’s a great way to spend an afternoon.
Want to learn more about the many bees that live in our community, why they are important and how to help them by becoming a citizen scientist? Join us for “The Buzz on Bees” via Zoom at 6 p.m. Wednesday, June 16. Registration is required.
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