While bumble bees, carpenter bees and other large bees are readily spotted flying throughout their environments, most of the bees native to the United States are much smaller and can be easy to miss.
Sweat bees are prime examples of this. Despite being some of the most common bees worldwide, sweat bees are mostly around the size of a grain of rice and normally perform their pollination services completely unnoticed.
There are believed to be around 1,000 species of sweat bees throughout the country, many with unique nesting habits and social structures. Most are solitary and dig small nests into soil or rotting logs, where they provision their young with enough food to last them through adolescence before sealing them off into protective rooms.
As they work to gather enough pollen for their young, sweat bees are excellent pollinators of both native and non-native plants. If you couldn’t guess from their name, these bees are known to visit sweaty humans in order to collect salts, water and other nutrients found in our sweat. This should not be a cause for alarm, however, as these gentle bees aren’t apt to sting and will quickly move on after they’ve quenched their thirst.
Sweat bees come in a wide range of colors. Some are jet black, while others have a cold steel sheen when viewed in the sun. Other sweat bees are more flamboyant in their colorations, with certain species sporting metallic greens, yellows, blues and even purples.
While these flashy displays can make sweat bees stand out to our eyes, scientists believe that the iridescent colors found on bees, beetles and other insects are actually used as camouflage designed to hide their outline and confuse potential predators.
These colorations vary between different species, but in general, if you see a flying insect with splashes of brilliant iridescence it is probably a sweat bee.
Sweat bees don’t only have a wide range of colors, their nesting habits and life cycles are also different, depending on the exact species.
In the millions of years that they have fine-tuned their lifestyles, multiple bee species have decided that working together in a shared nest is more beneficial than tackling the world alone. The methods and motives for this switch from solitary life cycles to social living are still largely a mystery; however, sweat bees actually give scientists a window into the impetus behind this change.
Many types of sweat bees are able to change their living arrangements depending on their surrounding environment. These adaptable insects take it upon themselves to work together in times of need and are able to live alone if the time and location call for it. It seems that some sweat bees are in the process of evolving into social forms.
By studying these “intermediary” species, scientists can get a better idea of how and why social bees like bumble bees and honeybees came about. Many species which are solitary also enjoy nesting close to other sweat bees in a bee community, forming dense groups of nests.
Sweat bees are advantageous in their nest construction compared to other bees, and they normally have very different nests compared to each other depending on local soil conditions. Some species have even been documented to have developed staggered emergence times for their young, in order to protect against droughts or other poor conditions.
Sweat bees are a pleasant and helpful addition to any landscape, and populations are easy to foster. Leave rotting logs where they are to give wood-nesting sweat bees a place to nest. For the rest, areas of bare soil that receive full sun are welcome sweat bee home sites.
Brannen Basham and his wife, Jill Jacobs, operate Spriggly’s Beescaping, a business dedicated to the preservation of pollinators. Contact him at firstname.lastname@example.org.