Leafcutter Bee (Megachilidae)
More bees with teeth! Female leafcutters use their chompers (mandibles) to cut plant leaves to line their nests.
“Their nesting activities leave neat, rounded holes in roses, redbud and other leaves, so they are considered a garden pest by some,” says Shepherd. “But they deserve a PR makeover!” Indeed, they don’t harm plants, just damage their aesthetic.
Leafcutter bees come in many sizes, but you can tell them apart from other bee families because the females have pollen collecting hairs on the underside of their abdomens instead of their legs. They also have larger heads because of their particularly muscular jaws. You can find them throughout the country.
Some people put up bee houses to entice them and mason bees into their gardens. Milam warns against this in most cases, because the structures are almost always parasitized by wasps, flies and birds.
Mason Bee (Osmia)
Because mason bees are solitary and don’t make honey — and thus don’t have to worry about protecting queens and their sweet, sticky stash — they tend to be more laid-back than their hive-dwelling cousins.
They’re in the same family as leafcutter bees, so also collect pollen on their bellies. These super-pollinators are also wise, choosing to nest a convenient 300 feet from the best flower patches.
Mason bees are some of the first bees to come out and greet us in the spring. They’re slightly smaller than honey bees, and come in green, blue or black, sometimes with a metallic tint. They’re found across the country, mostly in forests and deserts.
“They get their name from their ability to use mud to create partitions between individual eggs,” says Ali. “Mason bees are especially your friends if you are growing early spring blooming plants or fruit trees. You can encourage them into your garden by putting up bee houses.”
Squash Bees (Peponapis)
Squash pollen is bitter, and few insects can digest it. This is great news for squash bees! These persnickety buzzers forage exclusively on squash and gourd plants (Cucurbits).
They’re also earlier risers than most bees, getting to the squash flowers early in the morning, just as they’re opening. They conveniently live below the plants they pollinate.
“Their plants are native to the southwest, but now found all over, thanks to the crops being moved around by people,” says Shepherd. “And the bees have followed the squash plants. Squash bees are amazingly mobile and able to find areas planted with these crops like farms, community gardens and backyards.”
Squash bees are more common in the desert southwest, where squash originated. But starting about 1,000 years ago, they followed human agriculture into the Intermountain West and beyond, into New England and more recently the Northwest. They look a lot like honeybees, but a little bulkier, with a rounder face and longer antennae.