A Rubber Rabbitbrush Bee Safari
Take a drive through the arid lands of western North America any autumn day and you’ll find the roadsides dotted in gold. It‘s rubber rabbitbrush season, a ubiquitous shrub with thousands of yellow flowers, and a late season treasure for pollinators. If you stop the car and get out for a close look, you’re likely to discover a small fortune of bees.
That is exactly what I did one sunny September day as I drove a few of the lonely two-lanes of Washington State’s Columbia Plateau. I have made many trips to this part of the world over the years and have likely driven hundreds of miles of road lined with this shrub, but never once at bloom time. It was a welcome respite from the coastal areas and mountain meadows that by early fall had all gone to seed. A regional wildflower grand finale of sorts, for plants and bees alike.
Rubber rabbitbrush, Ericameria nauseosa, is a desert native also known by the common names gray rabbitbrush and chamisa. A true winner of evolution, It can be found throughout the western States and Provinces, thriving in places with harshly treated soil and little rain. It comes in a vast variety of shapes and sizes depending on where in the world you find it. Those that I met on the Plateau averaged about 3-5 feet tall, with a shape I can best describe as a roundish clump with a few lumps. They have numerous long, gently snaking stems radiating from a central point and slender, needle-like leaves, which in abundance are quite a dreamy misty gray with just enough green to suggest photosynthesis is happening. At the end of these stems grows the season’s crown of countless yellow, tube-like flowers.
It is on these flowers the bees congregate in great number and variety. In just a half day’s time covering rabbitbrush patches over a hundred miles or so, I would find the likes of several genera. Most numerous without question were bees of the genus Colletes, the plasterer/cellophane/polyester bees. It appeared to be one species, or perhaps several similar kinds that looked gray with a thick white coat of hair and deep black eyes, bees that with a little thicker hair wouldn’t look out of place in the snowy arctic. Both males and females were present. These were a treat to see, since my home west of the mountains rarely sees a visit from a this genus. Perhaps I should plant some rabbitbrush. The gardener in me certainly wondered how it would do in a rainy coastal garden.
Another genus present in much smaller numbers (and much smaller size) than Colletes included fairy bees (Perdita spp.). I found a species with a white and black-striped abdomen, green eyes, and reflective greenish/gold integument. Trying to keep track of these impossibly tiny bees zapping from flower to flower at impossible speeds in the bright sunlight required my darkest sunglasses and a quick camera. Getting a photo was a grand stroke of luck.
A little easier to photograph, and lovely to look at were the handsome Halictus, or furrow bees. In particular a large tawny-colored species and the ubiquitous Halictus ligatus, the ligated furrow bee. This prompted me to review the definition of ligated on the Merriam-Webster website, which means to tie with a ligature, which is something that binds or ties together. I looked long and hard at photos of Halictus ligatus to see where this name is derived from. I am at a loss. Perhaps it has something to do with its behavior or nest building.
After the Halictus, I spotted some sporty-looking Dianthidium pebble bees, which actually apply the stereotypical yellow and black paint scheme but have a chunky appearance akin to a bulldog. These bees carry pollen on the underside of their bellies, like mason and leafcutter bees, and are known to create elaborate nests out of tiny rock pebbles.
Speaking of elaborate, always winning best in show are the beautiful Agapostemon metallic green bees. I would only find one during my foray, a magnificent male. These bees glow on whatever flower they are found but particularly on anything yellow. Of course, rubber rabbitbrush has no shortage of yellow, making this bee a magnificent touch.
So before you batten down the hatches and settle in for a long and bee-less winter, go for a ride on a desert road in fall and take in the rubber rabbitbrush. It's a figurative pot of gold that will keep you well-funded until those March days when the bees make their return.