• Family: Colletidae
• Approximate # species in region: 22
• Common name: cellophane bees, polyester bees, silk bees

Colletes are small to medium-sized bees with strong abdominal banding. They are named for the thin cellophane-like lining that they use to line brood cells. Colletes in our area range from common garden bees to species so rare they are practically unknown to science. All Colletes nest in the ground – a few species form dense, conspicuous nesting aggregations in lawns or bare soil, resembling a field of tiny volcanoes (or large anthills). Nests of summer and fall species are parasitized by bees in the genus Epeolus.

Distinguishing Colletes from Andrena is challenging for many beginning bee watchers. Colletes have convergent eye margins whereas Andrena have parallel eye margins (see below). In the net, Colletes often have a sweet lemon scent, unlike superficially similar Andrena. Also note subtle differences in the body shapes of these genera – Colletes have rounded, conical abdomens, while the abdomens of Andrena are more vertically compressed or flattened.

Regional Species List: