Many bees (and other insects) can be found on blooming Willows early in the spring, including at least 6 Mining Bee species that are thought to be specialists. While willows are ubiquitous in most damp environments, they are often overlooked as a pollinator plant since the flowers are inconspicuous and often out of reach. Binoculars and/or a telephoto lens are very useful to fully appreciate one of the first spring pollinator shows.

Blooming Willow sp. © Spencer Hardy
Genus level ID: See the Mining Bee page for tips on separating other genera. In particular, compare the Unequal Cellophane Bee (Colletes inaequalis), which can be abundant on Willows and is superficially similar to a Mining Bee.
Many species of spring Mining Bees will visit willows, including many that are not identifiable from photo – in particular see subgenus Melandrena, which are common on willows and other spring flowers.
The species below are thought to be specialists and easiest to find on willows. They are in in rough order of abundance and distinctiveness. Click each box for more details on a given species.

Clark's Mining Bee (Andrena clarkella)
This large species is about as distinctive as Mining Bees can be. Females are very fuzzy with bright orange hairs on their hind legs. A northern species.

Frigid Mining Bee (Andrena frigida)
One of the first bees to emerge in the spring. Closely related to Clark's Mining Bee and similarly hairy. The abundant white hairs on the abdomen are a good clue.

Red-tailed Mining Bee (Andrena erythrogaster)
This appropriately named species is distinct among the Vermont Mining Bees, though two other Mining Bees often found on Willow also have red abdomens, but so far have not been found in the state.

Small Willow Miner Bee (Andrena salictaria)
Small, but likely not identifiable from photos.

Eastern Willow Miner Bee (Andrena bisalicis)
Likely not identifiable from photos.

Sigmund's Mining Bee (Andrena sigmundi)
A relatively robust species. Likely not identifiable from photos.

Black Miner Bee (Andrena nigrae)
This small species is quite rare in Vermont. Quite similar to Sigmund's Mining Bee and challenging to ID from photos.
Unless otherwise specified, photos are courtesy of Margarita Miklasevskaja at PCYU with funding from NSERC-CANPOLIN. Specialization data primarily from https://jarrodfowler.com/bees_pollen.html