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All About Blue Bees

We’ve all seen honey bees and bumblebees with their iconic black and yellow appearance.

But did you know there are bees that are blue? They look amazing, almost like they’ve flown right out of a child’s imagination. While you might not have seen one, they aren’t as rare as they sound.

Blue bees are fascinating and colorful insects, so keep reading to learn all about them and the role they play in agriculture and the ecosystem.

Orchard Mason bee or blue bees (Osmia lignaria) resting on a green leaf

What Are Blue Bees?

Osmia lignaria, otherwise known as the blue bee, orchard mason bee, or blue orchard bee, is a truly blue type of bee.

There are around 140 species of blue orchard bees total, and they’re actually much more common than most people realize. Blue bees are a type of mason bee and have the same nesting behaviors as other mason bees.

They’re called orchard bees because they tend to prefer living and foraging in orchards. Blue orchard bees are also related to other orchard pollinators such as leaf cutter bees.

Physical Characteristics of Blue Bees

As their name implies, they are very blue in color, usually a dark metallic shade. They can have varying degrees of coloring depending on the specific species.

Blue orchard bees share most of their physical characteristics with other mason bee species. They’re of comparable size to honey bees and have hairs on their abdomen and thorax. Female blue bees are larger than males.

Blue Mason Bee (Osmia lignaria) with pollen mites (Chaetodactylis krombeini) emerging from winter nest

Other Types of Blue Bees

While blue orchard bees are the most common and recognizable kind of blue bee, there are a few other species that are also blue.

Sweat bees can have metallic blue-green coloring, and they’re an extremely common garden visitor that tend to look a bit like flies. There are also blue carpenter bees, blue banded bees, and neon cuckoo bees just to name a few.

Several other flying insects can look similar to bees and also have blue coloring, such as blowflies.

Where Blue Bees Are Found

Believe it or not, blue orchard bees are actually native to the United States and Canada.

They thrive in North America because they require cold temperatures to overwinter successfully as part of their lifecycle, so the climate is ideal. In fact, you can even have them in your garden regularly if you like by getting them a mason bee house.

There is a subspecies found in Florida as well, the very rare blue calamintha bee. It was believed that they had gone extinct, but recent sightings have shown that they are still around.

Blue orchard bees are most common in apple, peach, almond, plum, pear, and other fruit tree orchards. These locations offer them plenty of places to nest and forage.

Behavior of Blue Bees

Blue Mason Bee pollinating blue Camas wildflowers (Osmia lignaria)

Blue orchard bees are what’s known as a solitary species, which means they don’t live in colonies like honey bees.

There is no division of labor in solitary bees. Instead, each individual female blue bee builds her own nest, lays her own eggs, forages for resources for their nest, and defends her nest when needed.

These bees nest in small openings, preferring to seek out existing spaces they can use just like other mason bee species.

Once they’ve selected a nest they will go foraging for nectar and pollen, which are then kneaded into a ball and combined with saliva. It takes roughly 25 trips to gather enough resources for a single ball.

They will start the nest by adding the ball of nectar and pollen for the larva to eat when the egg hatches at the bottom of the nest. Blue orchard bees will then lay a single egg on top of the ball, then seal up that section with mud or clay.

The egg inside will mature into a fully developed bee with all the nutrition it needs to survive.

This pattern is repeated until the space is full, at which point they will seal it up and go find a new place to start another nest.

Each nest contains an average of five to eight eggs, with more males than females. This is because the females will need more resources in their individual cells. These nests will overwinter before the developed bees emerge in early spring, with each bee spending the majority of its life cycle developing inside the burrow.

Once the fully developed blue bees emerge from the nest in the spring they will mate before they do anything else. Males emerge first and will wait for the females, which can take days or weeks based on weather conditions.

Males are only able to mate once before they die, and females will mate just once or twice.

The males emerge first because the first eggs laid deepest in the cell will become female bees and emerge last. Male bees emerge first from the entrance of the nest so they can wait for the females.

This also means that in the event of a predator finding the nest, the male pupae will be sacrificed in hopes of protecting the females. Females are much more important to the survival of the blue orchard bee species, so this arrangement gives them the best chance of survival.

Despite being solitary, blue bees do seem to prefer to build their nests near other blue bee nests.

Unlike many other types of bees, blue bees carry the pollen they collect on their bellies instead of their legs. This is a characteristic unique to mason bees, so you won’t see the “pollen pants” that honey bees and bumblebees are known for.

Rather than flying up to several miles away to forage like honey bees do, blue orchard bees will instead visit flowers closest to their nests for nectar and pollen. Females will forage all day until the sun goes down, then wait until the next day.

Once the sun rises and they are warmed up enough, they’ll get right back to work and continue foraging.

Female blue bees usually live four to eight weeks and will fill about four tubes with eggs on average, assuming a 6 inch tube with 8 eggs inside.

Most adult females will die off some time during the summer. By this time their larvae have finished consuming their resources and have begun to spin a cocoon around themselves to enter the pupal stage of their development.

Blue Bees as Pollinators

Osmia lignaria, commonly known as the orchard mason bee or blue orchard bee, is a megachilid bee that makes nests in reeds and natural holes.

Like other bees, blue bees are important pollinators.

Since they are so often naturally found in orchards, growers will often bring them in to keep the populations strong. They help ensure the trees get pollinated and are able to continue producing fruit.

In fact, as native species they are even better and more effective pollinators than honey bees are. Blue orchard bees are one of the few native bees actively managed for agricultural purposes because they’re so beneficial, even though they don’t technically produce anything.

Threats to Blue Bee Populations

Unfortunately, blue orchard bees are susceptible to the same threats as so many other bees and pollinators today.

Climate change and loss of habitat are a global issue, and North America is no different. Native flowering plants are the best resources available to bees, but many are crowded out by invasive species or removed in favor of more decorative plants.

With the widespread popularity of lawn care, many spaces are no longer hospitable to blue bees. Lawns do not offer any housing or foraging opportunities, and are frequently sprayed with pesticides.

Speaking of pesticides, pesticide use is another major threat to blue orchard bees. These chemicals aren’t able to target only certain types of insects, so they are harmful for bees as well. Even herbicides can cause problems if applied on or near flowering plants that bees typically visit.

We can help protect blue bees by reducing pesticide use, growing native plants, using fewer resources on lawns, and providing mason bee houses for them to use to nest. It’s also important to help educate friends, family, and neighbors so they can do the same to support blue bees and other pollinators.

They’re very beneficial for the ecosystem and home gardens, so it’s good to have them around and give them safe places to propagate. For anyone who grows fruit trees, they’ll be an especially useful helper to have on your property.

Best of all, blue orchard bees are nonaggressive, very rarely stinging and only if they feel extremely threatened. There is no need to consider them a problem or fear them if you’re worried about getting stung.

The Stunning Blue Bee

Not only are blue bees incredibly beautiful to look at, but they’re also prized for their pollinating abilities.

You may even be able to spot one if you visit an orchard and look carefully, as they’re relatively common in North America. It’s not unusual for orchard keepers to bring in more blue orchard bees for added pollination benefits.

If you love learning about different species of bees, honey bees are among the most interesting and best studied!


Friday 16th of June 2023

I live in central florida and I have these bees all over my plants. Absolutely beautiful!