Hyleus

Hyleus is a genus of bees belonging to the family Colletidae, commonly known as masked bees or yellow-faced bees. They are a diverse group, found worldwide, and are characterized by their slender, almost hairless bodies and the presence of yellow or white markings on their face.

Description: Hyleus bees are typically small to medium in size, often measuring less than 10mm in length. Unlike many other bee species, they lack a pollen basket (scopa) on their legs or abdomen. Instead, the female bees carry pollen internally in their crop (a specialized sac in the digestive system). Their bodies are generally black, with distinctive yellow or white facial markings that vary between species and sexes. The males often have more extensive facial markings than the females.

Habitat and Distribution: Hyleus bees can be found in a wide variety of habitats, including forests, grasslands, and urban environments. Their global distribution encompasses most continents, reflecting their adaptability.

Nesting Behavior: Hyleus bees are solitary nesters. Females construct nests in pre-existing cavities, such as hollow stems, beetle burrows in wood, or cracks in walls. They line the nest cells with a cellophane-like secretion produced from Dufour's gland, a characteristic trait of Colletidae bees. This cellophane-like lining serves to protect the developing larvae. Each cell is provisioned with a mixture of nectar and pollen, upon which a single egg is laid.

Diet: Adult Hyleus bees feed on nectar from a variety of flowering plants. The larvae are fed with a mixture of nectar and pollen collected by the female bee.

Role in Pollination: While they do not possess the typical pollen-collecting structures of other bee species, Hyleus bees contribute to pollination as they inadvertently transfer pollen while foraging for nectar. However, due to the internal transport of pollen, their efficiency as pollinators compared to bees with external pollen-carrying mechanisms is a subject of ongoing research.

Classification: The genus Hyleus is classified within the family Colletidae and is further subdivided into numerous species. Taxonomic classification can be complex and subject to revision based on ongoing research.