Bicolored Striped Sweat Bee - Agapostemon virescens
These gorgeous metallic green insects return for a blog post once again after a long hiatus. For those curious as to why, identification is very particular for the 4 Agapostemon species which call Ontario home, and after the last time I spoke about such a sweat-loving insect, there couldn’t be any second-guessing done this time. As such, I’m fairly confident that the delightful Bee featured scurrying about these echinacea flowers is a Bicolored Striped Sweat Bee thanks to its brown-colored wings, dark legs, and a noticeable lack of dense hairs on its thorax. The Silky Striped Sweat Bee (A. sericeus) was also in consideration at the start, but quickly ruled out as the females of that species have an exoskeleton coated entirely in an iridescent green shell. The males are a closer match, but the abdomen shape is more cylindrical, features an additional segment, and features prominent stripes of yellow, rather than white banding. Considering that information, it would benefit to remember this when observing and attempting to identify striped Sweat Bees using live specimens or pictures. The abdomen banding colors mentioned above seems to be ubiquitous across many of the North American Agapostemon Sweat Bees: the female Bees that feature banding or prominent hairs on their abdomen usually sport white coloration. Meanwhile the banding of a male Bee’s abdomen will feature yellow, or milky-yellow coloration in addition to a longer, more cylindrical abdomen (as mentioned above) which lacks a stinger. Based on the aforementioned characteristics, it’s likely safe to say that the green and striped individual walking along these echinaceas a Bicolored Bee, and it is also a female individual.
It’s quite fortunate that this Sweat Bee is one such species that is relatively straightforward to identify given the sheer magnitude of Bees to choose from. Specifically, those within the family Halictidae, which is technically composed of many subfamilies beyond Sweat Bees, those of which are sorted into the subfamily Halictinae, alongside Furrow Bees. This is just to say that even though Sweat Bees are just a branch within a larger family, there are may species to potentially find and observe. Furthermore, many species of Sweat Bee feature iridescent exoskeletons, which can make identification without more distinctive traits more difficult. It is for that reason why I’ve been more cautious when attempting to identify all-green, metallic Bees. While researching potential methods of more efficiently identifying North American Sweat Bees, I stumbled onto the tribe of Augochlorini, and the numerous genera within (around 30 worldwide, many are tropical). Based on the image finds, without a keen eye and some very close observations, particularly around the head of the insect, one would be forgiven if a Pure Green Sweat Bee was confused with A. sericus. Fortunately, there is no confusion with today’s Bee, and we can observe it with confidence. If you’re observing one in the wild, there’s little danger in getting close to them as the species is skittish and isn’t keen to sting, with the sting itself being fairly weak. For those curious, Justin Schmidt rates the sting pain of Sweat Bees in his book a 1 (out of 4). While weak, that’s no reason to provoke a Bee.
Pictures were taken on July 10, 2022 with a Google Pixel 4.
