- Author: Kathy Keatley Garvey
What was that foraging on a pink iceplant blossom near a path to the ocean? A metallic green sweat bee, Agapostemon texanus, also called an ultra green sweat bee.
We usually don't see A. texanus unless it's spring or summer, but there it was, out of season. Or rather, there "he" was. Males and females are easily distinguishable. The female is solid green, from head to thorax to abdomen, while the green coloration on the male appears on the head and thorax.
We remember pollinator specialist Robbin Thorp (1933-2019) emeritus professor of entomology at UC Davis, talking about them. He delighted in seeing them at his monitoring site, the Department of Entomology and Nematology's Häagen-Dazs Honey Bee Haven on Bee Biology Road, UC Davis campus. The Agapostemon are members of the Halictinae family. They are often called "sweat bees" because they are attracted to human sweat, probably for the salt.
Green sweat bees are among the bees featured in the book, "California Bees and Blooms: A Guide for Gardeners and Naturalists," co-authored by the University of California team of Gordon Frankie, UC Berkeley; Robbin Thorp, UC Davis; and UC Berkeley affiliates Rollin Coville (photographer and entomologist) and Barbara Ertter (plant specialist). Frankie, Thorp, Coville and Ertter (and others) also published "Native Bees Are a Rich Natural Resource in Urban California Gardens" in California Agriculture.
- Author: Kathy Keatley Garvey
The vibrant colors of Cosmos, an annual flower with the same common name as its genus, are spectacular. But we especially like the showstopping pink Cosmos with its bright yellow center.
Well, sometimes, they have a green center--that's when an ultra green sweat bee is foraging.
The female Agapostemon texanus is solid green, from head to thorax to abdomen, while the male of the species has a solid green head and thorax. It begs to differ with its abdomen; it's striped yellow and black, as if an artist ran out of green paint.
Agapostemon texanus is one of the bees featured in California Bees and Blooms: A Guide for Gardeners and Naturalists, the work of UC Berkeley-affiliated scientists Gordon W. Frankie, Robbin W. Thorp, Rollin E. Coville, and Barbara Ertter. Thorp, a distinguished emeritus professor of entomology at the University of California, Davis, received his doctorate in entomology from UC Berkeley, so there's the Berkeley angle!
If you want to learn more about native bees, check out Native Bees Are a Rich Natural Resource in Urban California Gardens, published by Frankie, Thorp, Coville and Ertter (and others) in California Agriculture.
Another good source is the UC Berkeley Urban Bee Lab, directed by Professor Frankie. It has an easy to remember URL: http://www.helpabee.org/.
Meanwhile, how green is your Cosmos?
