From The Mercury News
March 12, 2018
DEAR JOAN: I grew a pussy willow tree from a stalk I got at Safeway maybe three years ago. It is nearly finished with its catkins for this season, but there have been little swarms of tiny golden bees around them. Would you know what they are?
Jayne, Bay Area
DEAR JAYNE: They probably are native bees, but I can’t tell you exactly what type without seeing the bee. Actually, I probably couldn’t tell you even after seeing the bee — there are more than 1,000 species of native bees, and they come in a variety of sizes, so it would take a bee expert to identify the species.
It’s a little too early for honeybees, but the native bees are out. I’m not surprised the pussy willow has been covered with them. It is a great plant for bees, as it provides nectar at time when not too many other plants are blooming.
My guess is that the bees on your plant are mining or sand bees (Andrena). There are about 100 different species of this bee, and they are responsible for a lot of pollination of crops and plants. This species also provides pollination for both early and late-blooming plants.
There’s no need to worry about them. Most of the aggression we see in honeybees stems from their determination to protect the hive, but native bees don’t live in hives and are much more mellow. Enjoy the show while it lasts.