Excavator: Ground. Nests of this species seem to be well scattered, although several may occur in a relatively small area. For example, C.R. Vardy (pers. comm.) located a small, loose nesting aggregation in a level lawn at Harefield, Greater London, in July 1987. There, about nine nests were found in approximately 5.5 square metres of lawn, the burrow entrances being well concealed amongst the grass blades; each burrow was surrounded by a tumulus of excavated spoil. M. Edwards (pers. comm.) found a large nesting aggregation of this species at Porth Oer, a coastal cliff site in Gwynedd. This aggregation was estimated to occupy an area approximately 5 m long by 2 m wide on both level and steeply inclined, sparsely vegetated soil. There were at least 20 nest burrows per square metre. On St. Mary's, Isles of Scilly, G.M. Spooner (pers. comm.) observed many females burrowing into the soil on a cliff edge.
On the continent, the nesting habits have been described, and a cell figured by Malyshev (1923a); his nests contained 2-7 cells. Tirgari (1968) described artificial nest sites established under laboratory conditions. The prepupa and pupa have been described and figured by Rozen & McGinley (1974).
Parasites and predators: Nomada flavopicta is a probable cleptoparasite (see Yarrow, 1941; and Tengö & Bergström, 1976). Specimens of this Nomada were also observed inspecting burrows of the Melitta in the Harefield and Port Oer nesting aggregations described above. D.B. Baker (pers. comm.) has repeatedly found this Nomada with M. leporina on Oxshott Heath, Surrey.