Sladen states that a queen belonging to the virginalis form of Bombus terrestris often invades a nest belonging to the lucorum form, kills the rightful queen, andtakespossession of the nest, getting the lucorum workers to rear her young.
The colonies of Bombus illustrate the rise of the inquiline habit.
Kronfeld has shown that aconites are dependent for this on the visits of a Bombus and cannot exist outside the area where it occurs.
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.
Von Jhering, who points out that their wax glands are dorsal in position, not ventral as in Bombus and Apis.