Article By Dan Kirk
While last month we focused on one type of pollinator, the butterfly, this month we will focus on the most famous pollinator of them all: the bee. Like potatoes, you may only know a few species, or at least recognize a few species. And, like potatoes, there are around 4,000 types of bee species, 1,600 of them being native to California (this is not true of potatoes). Out of those 1,600 species, there is one you may not assume is a bee, and it’s name is Agapostemon texanus, or the green sweat bee. The females are bright metallic green, and you may just see one land on your sweaty arm! Much like the purple peruvian potato having received its name for being purple, sweat bees were given the name because they like perspiration and salt, which supply them with nutrients. Imagine, on one of these hot summer days, you are eating a purple peruvian potato salad outside, from which you are receiving many nutrients, and then a green bee lands on you, takes its tiny little tongue, and does the same. Interspecicial interdependence at its finest.
Agapostemon texanus, like us these days, are a very solitary ground nesting species. They dig deep vertical tunnels in flat or sloping soil. Solitary bees do not live in colonies, produce honey or have a queen, they do not produce wax to construct cells inside their nests and they do not have pollen baskets to carry pollen, meaning that they lose way more pollen than social bees and therefore are better pollinators. These sweat bees are non-aggressive and don’t swarm, bite or sting, unless they are severely threatened. The female Agapostemon texanus is completely green, while the male is half green half yellow and black striped, with the head and thorax (the part below the head where the wings are attached) being the metallic green area. They are pretty small, getting up to .5 inches long and fly pretty fast, so spotting can be difficult, though they have been spotted by The Watershed Project staff this year!
Though they are small and fast, they visit a wide variety of flowers, and actually, this is quite a skill. Some bees have a smaller range of host plants that they are familiar with and know how to, with speed, access the pollen from the flower. Each plant has a different floral morphology and extracting the nectar and pollen from many different flowers can slow things down, in fact, honeybees and bumblebees forage less efficiently the more flower types they visit. Sweat bees, on the other hand, are all individual foragers and do so indiscriminately, meaning that finding an area for these bees to pollinate is no hot potato.
Read more about how we bring pollinators to the Richmond area here!
Sources
http://beefriendly.ca/sweat-bees/
https://arboretum.ucdavis.edu/sites/g/files/dgvnsk1546/files/inline-files/10-bees-10-plants.pdf
https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/halictid_bees.shtml
