Appearance
They are 8-9 mm long. The male has narrow light tergite bandages, yellow face and normally hairy middle legs clearly visible in the field. The females are Clypeus yellow, but at the base with 2 large black spots, tergite 4 and 5 gray-yellow tomentose hairs, tergias with light hair ties in the field clearly recognizable. Both genders have olive green complex eyes and one very high, clearly perceptible flight sound. Habitat is important for identification.Naming
From Latin bi- "=" two "and" maculata "=" speckled ".Habitat
In sandy areas in lower locations: inland dunes and fields of drifting sand, sand pits, sandy embankments and ruderal places, forest edges and forest clearings. Nests on vegetation-free, flat surfaces or in small trailing edges. Nests only in fine and medium sands.Nests in self-dug cavities in the earth. Nests are found both in early succession stages with only little vegetation cover as also in late stages with heavy coverage. Nests have been found in the root balls of silver grass clusters. A main tunnel is 4-5 cm long deep in the ground. Under favorable conditions in small to large aggregations.Polylectic species. Known pollen sources are: Asteraceae: "Centaurea scabiosa", "Centaurea stoebe", "Cirsium vulgare, Picris hieracioides, Hypochoeris radicata"; Boraginaceae: "Echium vulgare, Anchuso officinalis"; Campanulaceae: "Trifolium arvense"; Hypericaceae: "Hypericum perforatum"; Lamiaceae: "Teucrium scorodonia"; Lythraceae: "Lythrum salicaria"; Rosaceae: "Potentilla incana". Except for the "Hypericum" species, all of the above serve both sexes as sources of nectar. Within the pollen loads 3 or 4 different types of pollen can be found. The field observations also showed that the flower visits on a pollen-collecting flight are randomly strung together, depending on the offer.
Parasites: "Ammobates punctatus" and "Coelioxys rufescens" are known as cuckoo bees; in England "Coelioxys elongata" was also observed on the nests.
Phenology: Univoltin. Flight period from the beginning of July to the end of August. Wintering as a resting larva.
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