Brood parasites and male mating strategy of Osmia pilicornis: 37 Female of the chrysidid wasp Chrysura hirsuta lurking near nest of O. pilicornis 38 Male resting on flexed grass blades lying on the ground 39 Male sucking nectar on flower of Pulmonaria mollis 40 Pair separating after copulation on the ground 41 Male with well visible hairs along the posterior margin of the antennae.