Types of Solitary Bees: A Friendly Guide to Bee Diversity

Solitary bees play an essential role in pollination and help maintain healthy ecosystems. Unlike social bees, such as honeybees, solitary bees live and work alone, with a single female building her nest and laying eggs. There are many fascinating types of solitary bees, and getting to know them can offer insight into their unique behaviors and contributions to nature.

One example of solitary bees is the mason bee, which builds nests in narrow cavities above the ground, often repurposing existing structures. Another interesting type is the metallic sweat bee, which can be solitary or communal and digs nests in the ground. These various types of solitary bees all have distinct nesting habits, colors, and sizes, making them a diverse group.

As you explore the world of solitary bees, you’ll uncover the differences in nesting behaviors, habitats, and appearances among these important pollinators. This knowledge can help you appreciate their role in maintaining biodiversity and guide your efforts to support and protect these vital creatures.

Understanding Solitary Bees

Solitary bees are a diverse group of bee species that, unlike social bees, do not live in colonies. Instead, they build and maintain their individual nests.

Behavior:

  • Most solitary bees are excellent pollinators
  • They are less aggressive than social bees, only stinging if mishandled

Some common types of solitary bees include:

  • Mason bees
  • Leafcutter bees
  • Carder bees

To better understand the differences between some solitary bee species, here’s a comparison table:

Bee Species Nesting Material Nesting Site
Mason bees Mud Wood cavities, hollow stems, or man-made bee houses
Leafcutter bees Leaf pieces Wood cavities, hollow stems, or man-made bee houses
Carder bees Plant fibers or hair Existing cavities, like abandoned rodent burrows

Solitary bees have unique nesting behaviors. For example, cavity-nesting bees create individual cells within their nests, laying one egg per cell and providing pollen for the larvae to feed on once hatched.

By understanding solitary bees and their behaviors, you can better appreciate the role these fascinating creatures play in our ecosystems, and help support their existence by creating suitable habitats in your garden.

Types of Solitary Bees

Mason Bees

Mason bees are small but mighty pollinators. They typically have a metallic green or blue color. As their name suggests, they nest in cavities and use mud to build partitions between cells. You might find mason bees inhabiting holes in wood or hollow plant stems.

Mining Bees

Mining bees, also known as tawny mining bees, are ground-nesting bees. They prefer to dig their nests in sandy, loose, and well-drained soil. These bees can range from metallic green to red in color and are great pollinators.

Carpenter Bees

Carpenter bees are robust and often mistaken for bumblebees. They differ from bumblebees in their nesting habits, as carpenter bees carve out tunnels in wood to build their nests, unlike bumblebees who nest in the ground.

Sweat Bees

These tiny bees are called sweat bees because they are attracted to human sweat. They have a great variety in color from black to metallic green or blue. While their sting is mild, their primary role is as pollinators for many plants.

Leafcutter Bees

Leafcutter bees are intriguing solitary bees that cut circular sections from leaves to line their nests. They are about ¼ to ¾ inches in size, and their color varies depending on the species.

Digger Bees

Digger bees, also known as plasterer bees, nest in the ground. They excavate nests under plants and prefer sandy, loose, well-drained soil. These bees can be metallic green, blue, or red in color and are essential pollinators.

Carder Bees

Carder bees are small, furry bees that resemble bumblebees. They collect plant materials, like the fuzz from leaves, to line their nests. This behavior is what gives them the name “carder.”

Wool Carder Bee

The wool carder bee is a specific type of carder bee. It’s known for its aggressive territorial behavior, and the males will defend their territory from other bees. They collect plant fuzz to line their nests, similar to other carder bees.

By familiarizing yourself with these varied species of solitary bees, you can better understand and appreciate their roles in the ecosystem and the pollination of plants.

Habitat and Nesting

Nesting in Ground

Did you know that around 70% of solitary bees nest in the ground? These ground-nesting bees often prefer sandy, loose, and well-drained soils. They excavate nests under plants in bare soil or sparsely vegetated areas (source). You may notice small piles of dirt on the soil surface with single large holes in the center (source). Luckily, these bees rarely sting unless extremely provoked.

Nesting in Plants

Some species of solitary bees find their homes in plants, such as hollow stems or leaves. They may lay eggs and create nests using plant material, leaving many species a crucial part of their habitat. For example, Virginia has several species of solitary bees, like mason bees and leafcutter bees, using plants to build their nests (source).

Nesting in Walls

Solitary cavity-nesting bees, like mason bees and carpenter bees, often nest in wood cavities. They utilize pre-existing structures such as abandoned beetle burrows. The female bee divides the structure into several cells, each containing a single egg that hatches into a larva (source). You can support these species by providing nesting opportunities in your walls or wooden structures.

Bee Hotels

Bee hotels provide a valuable habitat for solitary bees. They often contain different-sized tunnels, which mimic natural nesting sites found in the ground or plants. By installing a bee hotel in your garden, you’re offering a highly sought-after home for these important pollinators.

Pros of bee hotels:

  • Support various solitary bee species
  • Boost local pollination

Cons of bee hotels:

  • May require periodic maintenance
  • Possible pest invasion if not maintained properly

Remember to choose suitable placement for your bee hotel and clean it periodically to avoid pest buildup (source).

Lifecycle of Solitary Bees

Solitary bees have a unique life cycle compared to their social counterparts. In the spring, they begin their life cycle when the females emerge from their nests to mate and find suitable locations for their offspring.

After mating, the female solitary bee lays an egg in a small chamber or cell that she has prepared. Many solitary bees, like mason bees and leafcutter bees, use a variety of materials to create these brood cells. Some even use mud or leaves to form partitions between the cells. Solitary bees come in various colors and sizes, ranging from ¼—¾ inches.

Upon laying the eggs, the mother bee provides a food source for the larvae. This often consists of a mixture of pollen and nectar, which she places inside the brood cell. Once adequately provisioned, she seals off the cell and moves on to create additional cells with more eggs.

As the grub-like larvae consume the stored food, they grow and eventually pupate within the same cell. During this stage, they transform from a soft-bodied larva into an adult bee.

When the life cycle nears completion, adult bees emerge from their cells as fully developed and ready to take flight. This usually happens the following spring, meaning there is only one generation per year for most solitary bee species. Colletid bees, for example, emerge each spring and excavate their own nests without assistance from other bees.

To recap, the lifecycle of solitary bees involves:

  • Emerging and mating in spring
  • Laying eggs in brood cells and provisioning food
  • Larvae consuming food and pupating
  • Emerging as adult bees the following spring

By understanding the lifecycle of solitary bees, you can better appreciate their role in pollination and their importance to the environment. Always remember to provide a suitable nesting habitat and ensure there are available nearby sources of pollen and nectar to support them throughout their life cycle.

Feeding Habits

Solitary bees, like most other bees, primarily feed on pollen and nectar from flowers. They play a vital role in pollinating various native plants and flowering plants — ensuring their growth and reproduction.

You’ll find that these bees are attracted to different types of flowers, including those found in vegetable and fruit gardens. Here are some examples of plants they enjoy visiting:

  • Native plants, such as Joe-pye weed
  • Vegetables, like squash and tomato
  • Fruits, such as berries and melons

These solitary bees have different preferences in terms of which plants and flowers they forage. This can depend on factors like the time of the season and the species of the bee.

Here’s a comparison table illustrating some pollen and nectar preferences among different types of solitary bees:

Solitary Bee Species Pollen Preferences Nectar Preferences
Leafcutter Bee Legumes Various flowers
Mason Bee Fruit trees Fruit tree flowers
Sweat Bee Aster family Various flowers

When creating a habitat for solitary bees in your garden, it’s essential to incorporate a diverse selection of native plants and flowering plants throughout the growing season. This will provide these helpful pollinators with a continuous food source.

Remember:

  • Provide a variety of pollen and nectar-rich plants
  • Choose native plants and flowering plants
  • Plant vegetables and fruits to attract solitary bees

Pollination and Agriculture

As a vital component in agriculture, pollinators like solitary bees play a crucial role in the production of various crops. These hardworking bees contribute to the pollination of native plants, ensuring a healthy ecosystem and increased crop yields.

When it comes to pollinating crops, solitary bees visit a diverse range of plants. Some examples of crops they favorably impact include:

  • Alfalfa
  • Fruits
  • Vegetables

In comparison to social bees, such as honeybees, solitary bees can often be more efficient pollinators. This is because they’re more focused on collecting pollen for their nests, rather than nectar for honey production.

Solitary Bees Social Bees (e.g., Honeybees)
More efficient pollinators Less efficient pollinators
Focused on collecting pollen for nesting Primarily focused on nectar
Non-aggressive and less likely to sting More likely to sting if threatened

In your garden, consider incorporating native plants that attract these pollinators. By doing so, you’ll not only promote biodiversity, but will also support the local solitary bee population. To make your garden a paradise for solitary bees, try:

  • Planting a variety of flowering plants
  • Ensuring continuous blooms throughout the growing season

Remember, including these pollinator-friendly elements in your garden will not only enhance its visual appeal, but will also contribute to healthier agriculture and regional ecosystem.

Threats and Conservation

Solitary bees face numerous threats that, combined, contribute to their decline. Predators, like birds and wasps, can prey on these bees. Pesticides, used in modern agriculture, can poison their food supply. Barrages of diseases, invasive species competition, and reduced floral diversity can also impact solitary bees. Luckily, there are conservation efforts that aim to protect and bolster solitary bee populations.

Predators and Pesticides
Solitary bees are vulnerable to predators such as birds, wasps, and spiders. Additionally, pesticides can contaminate their food sources, like pollen and nectar. To minimize this exposure, try using organic gardening methods and reduce pesticide usage.

Disease, Competition, and Food Supply
Diseases like fungal infections, mites, and parasites can weaken solitary bees. They also compete with invasive species for resources. A decline in floral diversity affects their food supply. You can improve this by planting a variety of native flowers in your garden.

Conservation Efforts
Efforts are being made to improve bee habitats and support their populations. Here are a few steps you can take to help:

  • Plant a diverse range of native flowering plants that bloom throughout the year
  • Create a solitary bee hotel to give them shelter and breeding sites
  • Minimize pesticide use to keep their food sources clean
  • Educate others about the importance of these pollinators

Common Misconceptions

There are several misconceptions about solitary bees that are worth clarifying.

Firstly, many people believe that all bees make honey. However, this is not true for solitary bees. Unlike honey bees, which are social bees and produce honey in a colony, solitary bees do not produce honey, as they do not live in large social groups.

Another common misconception is that all bees sting. In reality, many species of solitary bees are stingless or have a very weak sting. For example, most mason bees and mining bees do not sting. Even when they possess a stinger, solitary bees are generally not aggressive and will rarely sting unless they are threatened or mishandled.

Some people may think that all bees live in large colonies or hives, like honey bees. However, solitary bees build their own individual nests and care for their larvae independently. Although they don’t have large social structures, a few solitary bee species might share nesting sites, which are called “aggregations.” These shared sites should not be confused with the highly social colonies of honey bees and other social bees.

Here’s a comparison table to help understand the differences:

Feature Solitary Bees Social Bees (e.g. Honey bees)
Colony No Yes
Aggressive/Stinging Rarely More likely
Honey Production No Yes
Nesting Individual nest Hive with complex social structure

So, when you encounter a bee, remember that it might not be a honey bee or a social bee species. Many of the bees around us are solitary bees, important pollinators that might share some similarities with honey bees but differ in crucial aspects like social structure, aggressiveness, and honey production.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Solitary Wasp

 

I hope you like identifying bugs!
What I’ve got is a fascinating flying dude. It’s totally black and about 1 inch in length with buggy eyes and a triangle head. New to me is that it actually looks at me (rather in my direction) when I move. I’m too used to houseflies that fly straight back into 8-week old spiderwebs after I (yes, I have an unexplainable fettish) untangle them from the web. Anyways, my concern is that it is dangerous in some way? At first I was convinced it had some diabolical reason for being in my house (mostly since it was so black and big!) but now I’m not so sure. However, appearances CAN be deceiving. I would love an I.D. for my lil’ buddy here, and perhaps some peace of mind.
Gratefully,
Rachel B.

Hi Rachel,
You have a solitary wasp from the Sphecine Family. They are not aggressive.

Letter 2 – Unknown Solitary Bee may be Sweat Bee

 

interesting red ’bee’?
Location: west flank of west flank coastal mountains above pescadero, california
May 26, 2011 9:14 pm
found this pollinator on a ceanothus blossom, above pescadero, california. i’ve searched through google without success. can you provide any information? this is purely a curiosity question so there is absolutely no hurry. i am an ardent gardener and am in the early stages of introducing bee hives to our san francisco neighborhood.
thank you!!!
Signature: chris dillon, san francisco, ca.

Solitary Bee

Hi Chris,
We are supposed to be reducing the number of images we need for our presentation at Theodore Payne Foundation tomorrow, and your photo would be an excellent addition.  We agree that this is a Solitary Bee, but we haven’t the time this morning to research the species.  It sure is a pretty little bee.

Update:
Perhaps this is the Mining Bee,
Andrena prima, which is represented on BugGuide from Oklahoma and Arizona.

good morning, daniel!
i’d be delighted to have you use my “red bee” image!  i love taking pictures of insects…& being recently retired, i can now do so more attentively.   i have a battered, because i’m clumsy(!), little canon power shot camera which suits my purpose very well.  i had a wonderful time capturing this image!
she is beautiful!
the red bee was the only one of her type amongs a busy crew of more traditional honeybees and two very loudly buzzing, seemingly irritable & frantic, huge glittering black solitary bees.  they were all engaged in harvesting from both fremontia and ceanothus plants/trees.  the red bee pictured was much less “vivacious” than her associates.  she systematically and thoroughly explored each petal of each flower which she chose to settle upon.   i was at yerba buena nursery, a magical  native plant resource, which is somewhat isolated on the western flank of the coastal mountains, between santa cruz and san francisco.  kathy, the owner, was able to provide info on the black bees.
thank you for your request!   i’ll now search for the theodore payne foundation which you mentioned…this retirement life certainly opens many “learning portals”!
chris

Update:  April 3, 2014
Thanks to a comment from Curious Girl, we believe this may be a cleptoparasitic Sweat Bee in the genus Sphecodes, which is well represented on BugGuide.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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5 thoughts on “Types of Solitary Bees: A Friendly Guide to Bee Diversity”

  1. This seems to be a Sphecodes cuckcoo bee:

    http://www.greatsunflower.org/Sphecodes

    I have a couple pictures of one last year in Porto going and coming out of a hole in the ground (presumedly a mining bee nest). At first I was afraid because of the bright red bottom but was then inspired to learn more. Now I am enamored of the bees and the flies which just seem to get more and more interesting.

    Reply
  2. This seems to be a Sphecodes cuckcoo bee:

    http://www.greatsunflower.org/Sphecodes

    I have a couple pictures of one last year in Porto going and coming out of a hole in the ground (presumedly a mining bee nest). At first I was afraid because of the bright red bottom but was then inspired to learn more. Now I am enamored of the bees and the flies which just seem to get more and more interesting.

    Reply
  3. I was stung buy a black bee it was about one inch long and to had a yellow dot on its back .i don’t know what kind it was but when it stung me my whole arm hurt .I took pictures and I have been stung buy a lot it things but never hurt this bad can you tell me what it is because it is still out there

    Reply

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