A dandelion poking through the rocks near Nick's Cove on Tomales Bay, in Marshall, Sonoma County, seemed an unlikely host for squatters' rights.
It first drew a tiny bee, barely a quarter-inch long. It was a female sweat bee, family Halictidae, genus Lasioglossum, subgenus Dialictus.
She claimed the dandelion all to herself.
Not for long.
Another insect shadowed the dandelion and swooped down to feed.
It was a hover fly, family Syrphidae. (Probably a Eristalinus aeneus, observed UC Davis pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis.)
So on one dandelion: a fly and a bee.
The fly is bigger. But the bee can sting. The sting, however, is rated only 1.0 on the Schmidt Sting Pain Index compiled by (now retired) entomologist Justin O. Schmidt at the Carl Hayden Bee Research Center, Tucson, Ariz.
Fight or flight?
The dandelion blossom belongs to the fly.