Colletes

Colletes is a genus of bees in the family Colletidae, commonly known as plasterer bees or cellophane bees. There are more than 100 described species worldwide, occurring in temperate regions across Europe, Asia, and the Americas.

Colletes are medium-sized, solitary bees. Each female constructs and provisions her own underground nest. Nests are typically dug in sandy or loose soil, though some species nest in debris or exposed crevices. A single nest contains a series of brood cells along an elongate tunnel. Each cell is provisioned with a paste-like mass of pollen and nectar, then sealed with a thin, glossy lining produced by the bee, giving the walls a cellophane-like appearance. After provisioning and egg-laying, the cell is closed and a new cell is added further along the tunnel.

Life cycle and development: Colletes are usually univoltine, producing one generation per year. Eggs hatch into larvae that consume the provisions, then enter a pupal stage inside the cell and overwinter as cocoons or prepupae. Adults typically emerge in spring, mate, and females begin new nests.

Ecology and behavior: They are generally polylectic, foraging on a wide range of flowering plants. As early-season nesters, plasterer bees are important pollinators in many temperate ecosystems. Their nesting and foraging activities can be influenced by soil conditions and habitat availability. Some nests may face pressure from land development and pesticide exposure.

Distribution and conservation: Colletes has a broad distribution in the Northern Hemisphere, with many species in Europe, North America, and Asia. While several species are common, others are rare or localized. Conservation concerns center on habitat loss, soil disturbance, and agricultural practices that affect nesting sites and floral resources.