Non-honey bees

Some bee species can use many various plants as their pollen sources (but still, they can have preferences) but there are others which are more or less specialized. The pollen specialists use plants belonging to only one family, sometimes their diet is restricted to just a few genera or a few species. They can’t live in areas where their food plants are absent. It shouldn’t surprise us, then, that pollen specialists are often rare or endangered.

On the drawing you see a pair of Clarke’s mining bee, Andrena clarkella, which collects pollen exclusively from willows.