Yellow-spotted Masked Bee
Hylaeus signatus
The Yellow-spotted Masked Bee is a small, predominantly black wild bee with characteristic yellow markings on its face. It belongs to the family Colletidae and transports pollen in its crop rather than on its legs. This species is strictly specialized on Reseda plants and prefers sunny, dry habitats such as ruderal areas, fallow land, and gardens.
Details
Identification
Black body, yellow face mask, yellow spots on the pronotum and wing scales (calli), labrum is black.
Social behavior
Solitary lifestyle; females establish their nests without help from conspecifics.
Diet
Oligolectic specialist on the genus Reseda (mignonette), particularly Reseda lutea and Reseda luteola.
Spawning substrate
Nests in existing cavities such as pithy stems, dry stone walls, holes in wood, or steep banks.
Overwintering
Overwinters as a resting larva in a cocoon within the brood cell.
Ecology
Ecological role
Important pollinator for specialized plant species of the genus Reseda.
Natural predators
Cuckoo wasps (e.g., Gasteruption species), spiders, and insectivorous birds.
Competitor species
Other wild bee species that utilize Reseda pollen, such as certain sweat bees.
Ecosystem service
Pollination of wild plants to maintain biodiversity in open-land habitats.
Threats
Loss of ruderal areas due to construction or intensive maintenance, decline of food plants due to herbicide use.
Scientific profile
Profile
Distinguishing features
Relatively large Hylaeus species. The propodeum is characteristically coarsely rugose. The species is strictly oligolectic on Reseda. Females possess conspicuous yellow spots on the pronotum, which are often absent or differently shaped in similar species.
Habitat
Thermophilic sites with occurrences of host plants: quarries, gravel pits, ruderal areas, railway embankments, vineyards, dry grasslands, and near-natural gardens.
Protection & threats
Main threats
Loss of ruderal areas due to sealing or succession; decline of host plants due to excessive mowing or herbicide use in agriculture and urban areas.
Population trend
Regionally variable in Germany; often listed on the early warning list (V) or as threatened (3), as specialized habitats are becoming rarer.
Conservation measures
Protection and promotion of Reseda stands; preservation of fallow land and ruderal sites; provision of nesting structures such as dead wood and bramble canes.