Sweat Bees - A Complete Guide
Sweat bees are an interesting species of bee. You may wonder where their name comes from—I can tell you, it’s not because they sweat. Sweat bees are very attracted to human perspiration—it’s actually a delicious snack for them.
Does that mean sweat bees are dangerous? Today we’ll answer that question, as well as everything else you need to know about them.
What Do Sweat Bees Look Like?
The sweat bee is a relatively common bee, but it often goes unnoticed until it lands on a sweaty arm. These bees are very small when compared to more famous species such as bumblebees or honeybees. It’s also not uncommon for people to confuse them with hoverflies, or even wasps.
Sweat bees stem from the Halictidae family, where there are many different types. They’re found in pretty much every country across the globe, except Australia.
We have around 1,000 different sweat bee species throughout the US, Canada, and Central America. Here, the Dialictus zephrum is most common. These bees aren’t honey producers, but they’re valuable pollinators, much like bumblebees.
If we look at its head, you’ll see a pair of antennae and two large eyes. One of the most mesmerizing things about this type of bee is their colorful bodies. Some are the usual brownish color with yellow stripes, while others range from metallic green and blue to silvery gray.
Because of the large variety, below we’ll go into detail of some of the most common sweat bees.
The Dialictus zephrum, or Lasioglossum zephyrum, is otherwise known as the common Eastern sweat bee. We can expect to find this bee all the way from Texas to the eastern coast of Canada and the states.
The Dialictus zephrum enjoys warm weather and is more commonly found between the spring and early autumn. After that, you’re lucky if you spot one.
The females have a very distinct brass-green color on the upper side of their bodies. Underneath their bellies, it turns into a more subtle reddish tone. Their metasoma has the usual yellow and brownish stripes.
Males, on the other hand, have more bright colors. The green color on their bodies is almost neon and under their bellies, you’ll see a vibrant red hue.
The Nomia melanderi is more commonly known as the alkali bee. These thrive in regions that are semi-arid or desert areas that are parched. You may expect to find them across the western US.
The alkali bees can easily be confused with wasps. Their bodies are long and slender, but in contrast to wasps, they have furry bodies. The females and males look quite similar, and likely the only way to tell them apart is by their antennae.
Males have very distinct antennae when compared to females. They appear more robust, almost like horns.
Both genders have quite fuzzy thoraxes. They’re not very colorful, but instead, their fur appears silvery in color. Looking down their bodies, they have the usual yellow/brown stripe combo on their metasoma.
This species is also known as Angeles striped sweat bee. This bee thrives throughout central and western US, although some have been found in Mexico and western Canada. They’re most commonly found throughout desert areas of southwestern US.
The Angeles bee striped sweat bee has an unmistakable appearance. Females have a bright, metallic green color across their whole body, including the metasoma. Males sport the same metallic green, but only up to their thorax. Their metasoma, however, has mixed bands of bright yellow and black.
Where Do Sweat Bees Live?
Sweat bees are common throughout the world, and fortunately, they are quite benign bees. More on that later.
These species thrive in different environments. Those we can find across the states do best in temperate areas. It seems that Florida is a favorite destination for many, where 44 species dwell.
Sweat bees are somewhat similar to the bumblebee. They prefer to live underground, where they dig tunnels and build nests. They can also carve out tunnels in soft wood.
If we take a look at the alkali bee, this specific species prefers salty soil, rich in alkaline. This is also where it got its name from.
The sweat bee female is responsible for finding a suitable nesting place. Once she has located her spot, she’ll dig out tunnels.
Sweat bees tend to prefer bare soil, without too much vegetation and roots nearby. They also enjoy the warmth of the sun. Because their nests are underground, it can get cold, so they often seek out an area that’s exposed to the sun.
This is another interesting thing about this species. They don’t live in typical hives or nests. Rather, they dig out large tunnels, creating their own communities where, at the end, they carve out cells for their eggs. Looking from above, their nesting areas look as if someone had poked holes in the ground.
Sweat Bee Colony Structure
The sweat bee species is a bit of a mix and match. Some types prefer to live solitary, while others tend to nest together under a queen and are therefore known as eusocial. They can also live in communities where several females will build their nests close to each other.
Some experts argue that their social behavior sometimes depends on the time of year or weather conditions.
Eusocial Sweat Bees
Eusocial sweat bee colonies are generally structured the same way as those of other bee species. There’s the gyne, or queen bee, the workers, and males.
The queen has a very dominant role within the nest, where she readily restricts food supplies to her worker larvae. She does this so that they’re smaller and easier to control.
After the first batch of brood has hatched, they’ll take over the nest building and will likely continue digging tunnels. The adults gather pollen and nectar, which they feed to the larvae.
The Dialictus zephrum is a known example of a eusocial sweat bee.
Solitary Sweat Bees
The solitary sweat bee colonies are spread far and wide, with quite some distance between each nest. The emerging females will venture out to mate and then find a place to raise their young.
Sometimes it happens that the queen’s daughters build nests near to hers. They carve out tunnels leading to each other’s nests and may even share an entrance. Inside, they care for each other’s offspring.
Agapostemon angelicus is the perfect example of a solitary sweat bee. The females nest far away from each other. Only the males may cluster together on a single flower during the night.
Semi-Social Sweat Bees
The same occurs in communal sweat bee societies. The newly emerged queens build their nests close together, where sometimes the tunnels beneath the ground combine. Some adults may guard a shared entrance to their hidden tunnels.
These shared nesting places can grow to an immense size with thousands of female bees working together inside. These are generally known as “semi-social” bees. The alkali sweat bee often lives in these semi-social colonies.
Male sweat bees, on the other hand, don’t have any particular role, except to mate with the females.
Cleptoparasitic Sweat Bees
There are also some roots of the sweat bee species that are known to be parasites. The females will find an occupied nest, kill the queen and lay her eggs in the egg cells. Her eggs will then feed on the present brood while the workers will tend to the parasite.
Are Sweat Bees Dangerous?
Sweat bees aren’t considered aggressive. They’re generally calm and known for minding their own business.
They can, however, sometimes get a bit too close for comfort for some people. Because they’re attracted to human sweat, they may hunt you down if you’re sweating it up in the backyard. They will merely land on your exposed skin and lick you.
Only the females sting if they feel threatened or if you press them. The stinger contains some venom, so if you do get stung, remove it as quickly as possible. It will continue to pump its contents into your system.
The venom is not dangerous and won’t harm you, unless you’re allergic or suffer from another condition which may react to the sting. Many also argue that the sweat bee’s sting is by far the least painful of all bees.
Sweat Bee Conservation Status
Sweat bees are very important pollinators. They’re polylectic which means that they’ll pollinate almost any flower or crop.
The conservation status of the sweat bee species is not concerning. Some people do find them a nuisance, especially if they keep swarming close to humans. It is possible to take measures to remove them by calling a local bee removal service. Don’t be tempted to call a pest control company, who will likely just destroy them.
If, however, the sweat bees aren’t necessarily disturbing you, then it’s best to leave them be. They do have an important role as pollinators.
Sweat bees are a common species of bee, but we often confuse them with other bees, hoverflies or even wasps. They come in beautiful colors and serve as important pollinators for our crops and flowers. Fortunately, they aren’t endangered, and they won’t sting unless provoked.