Ground Bees - A Complete Guide
The word “bee” usually makes us think about the usual stuff like honey, stings — and beehives. Truth be told, about 70 percent of all the bee species in North America nest underground. Ground bees are actually a whole category of bee species.
There are several common ground-nesting bees in North America. Each of these species plays an important role in the environment. Keep reading to learn more about these fascinating creatures.
What Do Ground Bees Look Like?
Ground bees look very similar to regular honeybees. However, there are a few ways to tell them apart. Let’s take a closer look at what the most common of these species look like:
The Colletes inaequalis, also called the polyester bee, looks very similar to the honeybee. The female is about half an inch long and the male tops at around ⅜ of an inch.
Both the males and females are covered in yellowish fuzz around the head and thorax. The abdomen features black and yellow stripes. They also have two sets of wings.
The polyester bee’s eyes are quite large and dark. Its antennae vary by gender, the female’s being dark, while the male has a more brownish color.
A key way to differentiate between the polyester bee and a honeybee is by the color. A honeybee is more bright in color while the polyester bee is more “earthy,” to fit into its environment.
The alkali bee is slightly smaller than the honeybee. Although often mistaken for a honeybee, the alkali isn’t as fuzzy.
The alkali bee has six fuzzy legs, and the thorax and abdomen are also easy to distinguish. The thorax is very dark in color and only slightly fuzzy.
The abdominal section consists of black segments separated by bright, iridescent stripes. The stripes are made up of enameled scales.
The Agapostemon bee is probably one of the most unique-looking bees out there. Ranging between 0.3 inches and 0.6 inches, these bees are often referred to as sweat bees. They are a bright metallic green color and have almost no fuzz, unlike other bees.
Some females will be all green, while others are more blue in color. The male will sometimes have a green thorax with a yellow and black striped abdomen.
The females are relatively fast flyers, but the males fly much slower as they’re often searching for females among the flowers.
The Andrena fulva bee, also called a tawny mining bee, is about the same size as a regular honeybee. The males, however, are slightly smaller and thinner.
The females are covered in fox-red colored hair, covering their thorax and part of the abdomen. Their underside and legs are covered in black hair.
The males are browner in color and have less dense hair compared to the female. They also have a very protruding jaw.
Where Do Ground Bees Live?
As you might already have guessed by the name, ground bees live underground. Ground bees dig tunnels or burrows in the ground. A tell-tale sign of a ground bee’s nest is small piles of dirt on your lawn; you might even see the entrance.
Some of the ground bee species are quite picky when it comes to the place they settle down. This goes especially for the polyester bee and the Agapostemon. These two species actually prefer to nest on sloping grounds.
The polyester bee takes this to a whole other level. These prefer to build their nest in sandy soil on south-facing slopes.
The females will also often build their nests close to each other, so you will surely notice them in your yard. They are solitary bees, meaning every female builds her own nest.
The Colletes inaequalis and Agapostemon bees can be found in North America. The Agapostemon is commonly seen all over the US while the polyester bee prefers the northeastern and midwestern regions.
You might be wondering why I keep mentioning polyester bees. Well, it actually has something to do with their nest. You see, the Colletes inaequalis line their nests with a cellophane-type secretion. They produce this using their two-lobe tipped tongue.
The secretion protects the still-developing bees from bacteria and fungal diseases. The protective layer also waterproofs the nest. This makes them very adaptive to different environments, they can even survive a flood-prone area.
The large tawny mining bees prefer more grassy areas. These are often found in lush gardens and parks.
They do still prefer south-facing locations, though, similar to most ground bees. The tawny mining bees, although found in the US, are more common in the UK.
Alkali bees, on the other hand, are quite unique when it comes to their nests. These bees are solitary, similar to the polyester bees, but they will build their nests very close to each other. They will also often connect the tunnels to create larger burrows.
The females usually dig long tunnels that lead to several egg chambers. The alkali bees prefer salty soil or even salt flats.
What Do Ground Bees Eat?
Ground bees are very important pollinators. Most of the species are more active during spring, which means they are responsible for spring plants, such as apple trees and blueberries.
The Agapostemon bees have quite short tongues. This gives them a very limited choice when it comes to plants and flowers to feed on. They have to find smaller plants as they can’t reach the nectar in deep flowers.
The alkali bees are important pollinators of alfalfa. This herb is very rich in vitamins and minerals, and often used in different medicines and supplements.
Tawny mining bees will feed on a range of trees and flowers, such as maple, willow, and dandelions.
Another bee species, which is common in California, is the Lasioglossum. This genus is a member of the sweat bee species. They are highly attracted to human sweat and will gladly drink some of our bodily fluids if they get the chance.
Are Ground Bees Dangerous?
Ground bees are not dangerous, in fact, most of them don’t even have stingers. Some females of a few species do have stingers, although they’ll only use them when they feel threatened.
If you or anyone in your family isn’t suffering from any allergies toward bee venom, ground bees should be nothing to worry about.
Ground bees are very important pollinators, so you might want to keep them around if you notice them. If you happen to find a tiny hole which might look like a ground bee’s nest, try to observe it. Keep an eye out for a single bee flying in and out.
If you notice any large wasps, though, like the yellowjackets, seek professional help. These wasps make nests similar to ground bees. The bees are friendly pollinators, while the wasps are extremely aggressive and short-tempered.
Ground bees are quite easy to get rid of if you don’t like the thought of having bees in your yard. Most ground bees prefer dry soil, therefore, all you have to do is water your lawn often. The bees will most likely find a different place to settle then.
I highly recommend you not to use any pesticides to get rid of ground bees. These bees aren’t considered pests by any means, and they play an important role in our ecosystem.
Ground Bee Colony Structure
Most ground bees are solitary bees. Solitary bee females are very independent, as they will find and build their own nest. Here they will raise their offspring without the help of drones or worker bees.
One species, in particular, has quite an interesting ritual after mating. The female tawny mining bee will hover above her nest and then flick its eggs into the opening, with great precision.
The Lasioglossum sweat bees can live as a solitary, communal, or social colony. In the social colonies, the daughters will often stay in the nest to care for the young. Other social colonies might consist of a queen and several worker bees. Some social colonies will even have several queens ruling a large number of workers.
Ground Bee Conservation Status
As we have said, ground bees are essential pollinators. Some people even consider them to be a clear sign of spring approaching. Keeping these tiny but mighty bees around is important.
One tiny bee that has proved to be the bread and butter of a whole industry, is the alkali bee. What we concluded earlier was that this bee feeds on the alfalfa plant, but here’s something interesting—previously, farmers would actually try to get rid of the alkali since they thought it was a pest.
Crops dropped and the alfalfa business took a dive. Once the farmers realized it was the alkali bee that pollinated the herbs, they brought them back. They now even optimize the conditions to create the perfect thriving spot for these mighty helpers.
Agricultural landscapes could be destroying ground bees’ natural habitats. Agriculture may also expose bees to pesticides, or reduce food sources. Now, though, there are a few conservation strategies taking place. These include, but are not limited to:
- Planting a variety of wildflowers.
- Installing blooming shrubs or trees.
- Leaving areas of bare soil or grass for the bees to nest.
- Providing access to clean water using bird baths or ponds.
We hope we’ve covered everything you need to know about ground bees. Remember, never take ground bees for granted; these harmless creatures can help make your garden a lush area. Ground bees are a great way to get ‘free’ pollination without having to deal with other, more aggressive, species.
Planting a range of bee-friendly plants or flowers in your yard is a great way to invite these little helpers. Never use pesticides or other deadly chemicals where ground bees are thriving. If you really don’t want ground bees around, try to make the area less desirable for them and they’ll likely find somewhere else to live.