Yellow Loosestrife Bee
Macropis europaea
The Yellow Loosestrife Bee is a medium-sized solitary wild bee closely associated with wetlands and floodplain landscapes. It is a highly specialized species that collects pollen and floral oils almost exclusively from Yellow Loosestrife (Lysimachia) species. Females use the collected oil to line their underground nests and mix it with pollen to provide food for their larvae.
Details
Identification
Females with white-haired hind tibiae; males with conspicuously club-like thickened hind femora and a yellow facial mask.
Social behavior
Solitary lifestyle; females construct their nests independently in the ground, often in small aggregations.
Diet
Oligolectic specialist on Yellow Loosestrife (Lysimachia vulgaris and L. punctata); collects oil instead of nectar for larval rearing.
Spawning substrate
Self-dug tunnels in mineral soil, often on sparsely vegetated embankments or under herb layers.
Overwintering
Overwintering as a resting larva (prepupa) within a cocoon inside the nest cell.
Ecology
Ecological role
Important pollinator for Yellow Loosestrife species and host for the rare cuckoo bee (Epeoloides coecutiens).
Natural predators
Cuckoo bees (Epeoloides coecutiens), insectivorous birds, and spiders.
Competitor species
Other Macropis species such as the Wood Loosestrife Bee (Macropis fulvipes).
Ecosystem service
Pollination of wild plants in wetland ecosystems.
Threats
Destruction of wetlands, lowering of the water table, and loss of Yellow Loosestrife populations due to intensive mowing.
Scientific profile
Profile
Distinguishing features
Specialized oil-collecting bee. Females possess significantly widened hind legs with dense white hairs for transporting floral oil and pollen. Males have characteristically shaped hind legs and yellow facial markings. Distinguished from M. fulvipes by the white (not yellowish) hairs on the hind tibiae in females and genital characteristics in males.
Habitat
Wetlands, floodplains, river and stream banks, moist forest edges, fens, and gardens with stands of loosestrife.
Protection & threats
Main threats
Loss of wetland habitats due to drainage, intensive mowing of riparian zones (removal of host plants), and habitat fragmentation.
Population trend
Widespread and mostly stable in Germany, but regionally threatened by the decline of wet meadows and near-natural banks (Red List Germany: V - Near Threatened).
Conservation measures
Preservation and restoration of wetlands, protection of Lysimachia stands, avoidance of mowing during the flowering period along ditches and banks.