When Irish eyes are smiling, it could be...
- St. Patrick's Day is approaching or
- A green insect is nearby
If you've ever seen the female metallic green sweat bee, Agapostemon texanus, or the sand wasp, Bembix americana, you can't help but think about the "Wearing of the Green." They're especially "fashionable" on St. Patrick's Day.
The female metallic green sweat bee, Agapostemon texanus, is green. The males are partly green; their head and thorax are green, but not their abdomen.
And the sand wasp, Bembix americana, who isn't mesmerized by those green eyes? (They might be smiling, too, on St. Patrick's Day, March 17).
Wishing you a pot of gold and all the joy your heart can hold. Happy St. Patrick's Day!
If you're walking along the cliffs of Bodega Head, Sonoma County, you may overlook them.
While you're watching for whales, scouting for seabirds and checking out the hikers, there's a lot of movement in the seaside daises (Erigeron glaucus) and seaside woolly sunflower (Eriophyllum staechadifolium).
Green-eyed bullets with spectacular abdominal stripes zero in on the flowers, grab some food (this really is "fast food") and then take off at break-neck speed.
They're sand wasps, Bembix americana, so named because they dig nest holes in the sand. They belong to the family Crabronidae, subfamily Bembicinae, tribe Bembicini (sand wasps), subtribe Bembicina, and genus Bembix. They're quite common in North America. We've seen them from Fort Bragg to Bodega.
They're not vegetarians, like our honey bees. Like all wasps, they're carnivores. They're hunters. They're predators. They prey upon small insects, such as flies. The sand wasps then carry their prey back to their nests.
So while you're watching for whales, watch the flowers. If they move, it may be more than just the wind.
Want to read more about sand wasps? Entomologist Richard Bohart (for whom the Bohart Museum of Entomology at UC Davis, is named), and his former graduate student, Arnold Menke, wrote about them in their book, "Sphecid Wasps of the World," published in 1976 by the University of California Press, Berkeley.
If it looks like a bee, sips nectar like a bee, and buzzes away like a bee, that doesn't mean it's a bee.
Last weekend we visited a Fort Bragg nursery specializing in succulents, and these "little white bees" were all over the red flowering thyme (Thymus serphyllum).
"Little white bees." That's what nursery personnel and visitors called them.
Not bees, though. Wasps.
But both in the order Hymenoptera.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, identified it as a sand wasp, genus Bembix, probably B. americana.
"These wasps fly very rapidly and frequently visit flowers," Thorp said.
Being a wasp, it's a predator and a carnivore, not a vegetarian like the honey bee. It preys upon flies, hover flies (aka flower flies or syrphids), tachinid flies, lacewings, and other critters, taking the carcasses back to its ground nest to feed its larvae.
The sand wasp digs its nest holes in the sand, thus its name. Its abdomen looks something like a basketball referee: except instead of black and white stripes, it sports curvy black and white stripes.
Bug Guide indicates that North America is home to 19 species of sand wasps.
This one (below) seemed to be sipping nectar (adults feed on nectar).
Probably a "matter of thyme" before it nailed a fly.