Other bees, the species of Osmia for example, choose the hollow stem of a bramble or other shrub, the female forming a linear series of cells in each of which an egg is laid and a supply of food stored up. J.
Fabre has found that in the nests of some species of Osmia the young bee developed in the first-formed cell, if (as often happens) she emerges from her cocoon before the inmates of the later cells, will try to work her way round these or to bite a lateral hole through the bramble shoot; should she fail to do this, she will wait for the emergence of her sisters and not make her escape at the price of injury to them.
But when Fabre substituted dead individuals of her own species or live larvae of another genus, the Osmia had no scruple in destroying them, so as to bite her way out to air and liberty.
The leaf-cutter bees (Megachile) - which differ from Andrena and Halictus and agree with Osmia, Apis and Bombus in having elongate tongues - cut neat circular disks from leaves, using them for lining the cells of their underground nests.
More violent in its methods is the larva of a Stelis, whose operations in the nest of Osmia leucomelana have been studied by Verhoeff.
The female Stelis lays her eggs earlier than the Osmia, and towards the bottom of the food-mass; the egg of the Osmia is laid later, and on the surface of the food.
Finally the parasitic larva attacks the Osmia, and digging its mandibles into its victim's head kills and eats it, taking from one to two days for the completion of the repast.