How to Identify Summer Leaf Bees
Many bee raisers want to learn how to identify the bees that visit their yards and gardens. With over 4,000 species of native bees in North America, plus non-native species that have been introduced, it can be challenging to identify bees down to the species level.
Even if we look only at Summer Leaf bees (often called Leafcutter bees), the task can be daunting. Approximately 242 species of Megachile bees are native to North America, plus the alfalfa leafcutter bee (Megachile rotundata), which has been established in North America for its agricultural services.
While we might not be able to identify down to species level, there are some common characteristics that the genus Megachile (Summer Leaf/leafcutter bees) share that can help you pick them out from other insect pollinators in your yard and garden.
Keep in mind that the following characteristics are general, and slight variations between Summer Leaf bee species are common.
Common characteristics of North American Summer Leaf bees
- Most North American species are approximately the size of the common honey bee. Males are noticeably smaller than females, have a more rounded abdomen, and longer antennae.
- Summer Leaf bees are often dark in color with light bands on their abdomen. Females typically have black eyes, while males may have green eyes.
- Summer Leaf bees have strong, scissor-like jaws used to cut and gather leaves, flower petals, and sometimes resin to construct their nests.
- Female Summer Leaf bees have parallel rows of pollen-collecting hairs (the scopa) on the underside of their abdomen. When a bee is carrying pollen, the underside of the abdomen can appear yellow or gold. Males do not have a scopa.
Despite having a stinger, female Summer Leaf bees are not aggressive and rarely sting, even when handled. Their sting is also much less painful than that of a honey bee, so you don’t need any special protective equipment when working with them. Male Summer Leaf bees do not have a stinger.
Helpful identification tools
If you’d like to dive deeper into identifying the bees in your yard, here are a few resources to help you along the way:
- Crown Bees has a great selection of books and bee identification guides to help you learn the bees in your backyard.
- Discover Life is a free online tool to help identify species, track the impact of climate change, and participate in research projects.
- Bug Guide is an online community of naturalists who collect photos of insects from the United States and Canada for identification and research. They also summarize findings in guide pages for each order, family, genus, and species.
- Exotic Bee ID (USDA ARS / APHIS and Utah State University) can help identify non-native bees in the United States. Some exotics, such as Osmia cornifrons, have become naturalized and may be seen pollinating farms and orchards. It’s still important for researchers to understand their distribution and abundance.
Exotic Bee ID is designed primarily as a screening tool for those who monitor and intercept non-native bees coming into this country, such as people working at ports of entry, state agriculture departments, and university extension services. However, it is also set up to be used by growers, hobbyists, and homeowners. Access is free.
Where our Summer Leaf bees come from
At Crown Bees, we currently only work with the alfalfa leafcutter bee (Megachile rotundata).
The alfalfa leafcutter bee was introduced into North America from Eurasia in the late 1930s and is now naturalized across North America. It’s an excellent pollinator for summer blooms. And despite the name, alfalfa leafcutter bees are generalists that visit many different types of flowers.
Check out Where Our Summer Leaf Bees Come From to learn more about where we source our alfalfa leafcutter bees.