Sweat bees are small, non-aggressive insects that often go unnoticed due to their size. While some species exhibit metallic green or blue colors, others may be black or brown, with markings similar to those of honeybees . Although these bees play a vital role in pollination, they can become a nuisance for some people as they are attracted to human sweat.
To prevent sweat bees from bothering you or nesting in your garden, it’s essential to develop an effective strategy. Implementing some simple measures, like reducing excess moisture and limiting nesting sites, can make a significant difference. Stay tuned for practical tips and tricks to help keep sweat bees at bay.
Understanding Sweat Bees
Characteristics of Sweat Bees
Sweat bees belong to the Halictidae family and are mainly recognized by their curved basal wing vein 1. They are small, and their color varies from green to red to yellow, often with bands similar to those of honeybees 2. Some common characteristics include:
- Small size
- Non-aggressive nature
- Short tongues compared to other bee types
- Bright colors, with metallic greens and blues
Sweat Bee Species
There are many species of sweat bees, or halictids, in several genera. One example is the green metallic sweat bee (Agapostemon virescens), which lives in underground communal nests 3.
Their Role in Pollination
Sweat bees play a vital role in pollination, as they can detect ultraviolet light helping them locate the flower’s center quickly. This adaptation benefits both the bee and the flower, allowing the bee to collect nectar rapidly, and the flower to be effectively pollinated 4.
Causes of Sweat Bee Infestations
What Attracts Sweat Bees
Sweat bees, also known as halictidae, are attracted to:
- Sweat: They are drawn to the salt in human sweat.
- Flowers: Sweat bees feed on nectar and pollen from flowers.
- Water sources: They need water for their survival.
For example, a garden full of flowers and a small water feature can entice sweat bees.
Ideal Conditions for Nesting
Sweat bees prefer certain environments for nesting:
- Soil: Most sweat bee species burrow into the ground.
- Loose materials: Some species nest in rotting wood or loose mulch.
Factors that contribute to ideal nesting conditions include:
- Availability of pollen and nectar: Gardens with various flowering plants.
- Soft, easily excavated soil: Sandy or loose soil is perfect for burrowing.
- Sheltered locations: Sweat bees avoid areas with heavy foot traffic or activity.
A comparison table of sweat bees and their nesting preferences:
|Sweat Bee Species
|Ground, soft soil
|Ground, sandy soil
Making sure your garden has minimal favorable conditions for sweat bee nesting can help reduce infestations:
- Keep soil areas compact or use ground coverings like gravel.
- Limit the number of flowering plants or opt for species that don’t attract sweat bees, such as sunflowers.
- Regularly clean up rotting wood and dispose of mulch piles.
- Maintain a tidy garden by mowing grass and tilling exposed soil.
- Use natural repellents like vinegar to deter sweat bees from certain areas of the garden.
Methods for Managing Sweat Bees
To prevent sweat bees from becoming a nuisance, follow these simple steps:
- Wear long pants and long sleeves to cover exposed skin, decreasing their attraction to you.
- After outdoor activities, shower to remove sweat, reducing their attraction.
- Avoid using strong fragrances that may attract sweat bees.
- Regularly clean up your yard to eliminate potential nesting sites.
Effective Sweat Bee Traps
There are various traps on the market to help manage sweat bees. Here are some effective options:
- Ronson Wood Trap: This reusable trap is designed specifically for sweat bees. It is environmentally friendly and easy to install.
- Metallic Green Trap: Effective for metallic green sweat bees. This trap lures them using a combination of colors and pheromones.
Traps can successfully reduce the sweat bee population in your area. Their pros include being easy to use and relatively low-cost. The cons include the need for regular maintenance and some ethical issues surrounding their use.
Using Insect Repellent
Insect repellents help keep sweat bees at bay. Apply repellents containing DEET or picaridin to your clothes and exposed skin. A few natural options include:
- Essential oils like citronella, eucalyptus, or lemongrass oil, diluted with water.
- DIY solutions including vinegar or lemon juice mixed with water.
Natural repellents are environmentally friendly but may need to be reapplied more frequently than chemical alternatives.
Bee sprays containing insecticides can be applied to affected areas to control sweat bee infestations. Always follow label instructions to ensure safe and effective use.
|Bee Spray Types
|Potent, fast-acting, long-lasting
|May be harmful to the environment
|Safer, environmentally friendly
|May need frequent reapplication
The choice between chemical insecticides and natural alternatives depends on personal preferences and considerations regarding the environment and safety.
Remember, while sweat bees can be an annoyance, they also play a crucial role in pollinating plants. Consider ways to manage sweat bees that minimize harm to these important insects.
Additional Tips and Considerations
Dealing with Allergic Reactions
Sweat bees, though less aggressive, are among the stinging insects and can cause allergic reactions in some individuals. If stung by a sweat bee, take the following measures:
- Remove the stinger as soon as possible
- Apply ice or cold pack to reduce swelling
- Consult a healthcare professional for severe reactions or difficulty breathing
To minimize the risk of being stung, wear protective clothing when outdoors, especially during their peak activity from April to November1.
Encouraging Beneficial Insects
Sweat bees are considered semisocial and act as pollinators1. However, if their presence is a problem, encouraging beneficial insects that do not pose a threat can help. Some examples of beneficial insects include:
- Praying mantises
Here’s a comparison table of sweat bee repellents:
|Natural, effective, non-toxic to humans
|May be harmful to some insects
|Sweat bee traps
|Can capture multiple bees
|May also trap beneficial insects
|Effective against various insects
|May contain harmful chemicals
|Effective, affordable, natural
|Limited range, needs replacing
To discourage sweat bee infestations, maintain a tidy garden and focus on planting alternative pollinator-attracting plants, such as stone fruits, alfalfa, and various flowering plants12. This will give sweat bees less reason to venture into your space, while still providing essential pollination.
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 – Sweat Bee
Bee, 1 inch long, loner, colored like a honey bee but not so fuzzy, antennas flare out and are long – see photos attached
November 9, 2009
Excellent site! Do you know what kind of bee this is?
We are relatively certain that this is a Mining Bee in the genus Andrena. According to BugGuide: “Considering the large number of similar-looking species, identification to species level usually requires an expert. Andrena are more active than Apis at lower temperatures. For this and other reasons Andrena (and Osmia…) can be, on a per bee basis, superior pollinators in cold weather. Some species such as Andrena clarkella are exceptionally cold tolerant.” We will check with Eric Eaton to see if he agrees with our assessment.
Correction courtesy of Eric Eaton
LOL! You’re not “far off” at all, Daniel. The Texas bee is a male halictid bee in the genus Nomia. I recognize it by the beefy hind legs of the male bees in that genus. There are many species so I’m not sure which one this is. John Ascher at the American Museum of Natural History might be able to be more specific.
Thank you so much. The plant, a Shepherd’s Needle, attracts several kinds of bee, wasp, flies, butterflies. I have been using your site to identify them. It has been very helpful.
Letter 2 – Probably Sweat Bee, NOT Mining Bee
Subject: Unknown Very Small Bee Species
Location: Lamar county, South Mississippi
December 25, 2014 6:14 pm
Above is a link to a video I posted of an unidentified bee species I found in my back yard one day. I realize the video isn’t the best quality but it’s all I have. They were so small once I left the area I couldn’t find them again to obtain a specimen. I can tell you my finger seen in the video is 2 cm wide, exactly, if you can use that for size reference.
If you pause it near the end you can get a decent profile of it and it’s characteristics. They lived in a small hole which was guarded by the abdomen of a colony member. They appeared to be gatherers but were so fast I couldn’t see what they were bringing back. My first impression was that I was looking at a queen fire ants (Solenopsis invicta) ready to swarm as the bees had amber, shiny bodies just like fire ants. But their flight characteristics said bee to me. They weren’t aggressive when I probed the opening with a small piece of grass, they just removed it and continued to keep the entrance sealed with an abdomen.
I have passed this video around to a few local entomologists and they keep telling me bees don’t get that small and they can’t tell without a specimen. All the research I have done has produced similar looking insects like Sphecodes but I can’t find any that fit into this size range.
Signature: Steven Cimbora
Your video shows what appears to be a Mining Bee in the family Andrenidae. According to BugGuide: “Many small, ground-nesting bees observed in areas of sandy soil are members of the family, Andrenidae. Characteristics of this family (of which there are approximately 3000 species) are: Small size, 20 mm, (or smaller) brown to black in color, and nesting in a burrow in areas of sparse vegetation, old meadows, dry road beds, sandy paths. Although the nests are built in close proximity of one another, the bees are solitary (each female capable of constructing a nest and reproducing). Many species are active in March and April when they collect pollen and nectar from early spring blooming flowers. The female bee digs a hole 2-3 inches deep excavating the soil and leaving a pile on the surface. She then digs a side tunnel that ends in a chamber (there are about 8 chambers per burrow). Each chamber is then filled with a small ball of pollen and nectar. An egg is laid on the top of each pollen ball and the female seals each brood chamber. The emerging larval bees feed on the pollen/nectar ball until they pupate.” We are shocked that your local entomologists have no knowledge of these native, small, ground-nesting Mining Bees.
Thank you for the quick response.
I just wanted to point a few things out that run contrary to the Mining Bee’s description based on my personal observations of them.
I observed fellow nest members guarding the entrance with their abdomen, as seen in the video.
The nest entrance is perfectly clean of any mounding or tunnel waste and I observed more than one bee leave and return to the entrance. A few times there were several hovering near it waiting to enter.
The size range of 20 mm or smaller is starting out at the width of my finger, seen in the video which is 20mm or 2 cm wide. I would estimate their size at about 5 mm at best and that was the bigger ones.
As you watch the very beginning of the video, right before I put my finger in frame, you will see one depart then another come to the entrance and block it with it’s abdomen. This is not a solitary bee as the mining bees are described as being. They also appeared to lack the pollen brush associated with Mining bees.
Thank you for the effort and if I can ever find them again I will definitely get a specimen.
Thanks for getting back to us Steven. We have tagged the posting as Unidentified and we have included a screen shot from the end of your video. Perhaps one of our readers has an idea what Hymenopteran this might be.
Update: January 4, 2015
I am providing a new link to some more footage of the unknown bees I found in my back yard. There is much more footage of their activity and it is stabilized. It also shows the presence of more than one bee occupying the nest at a time (Entrance guard) and better footage of their flight characteristics.
I went ahead and scaled some screen shots to try and get a better measurement of them and I came up with approximately 3.2 mm in length. I did this by scaling a screen shot of my finger until it measured the same as actual, using Gimp2 software to measure with. I then took a screenshot of the bee in flight and scaled it to the same dimensions and then measured it. The opening measured approximately 1.1 mm.
You might also find better images to capture and post in this footage as well.
Thank you for your time.