Abstract
The volatile chemicals, detectable by coupled capillary gas chromatography-mass spectrometry, in the nest cell linings of four species in the bee generaColletes, Andrena, andLasioglossum are identical with, and limited to, the volatile components present in the Dufour's gland of females, suggesting this source for some of their cell-lining constituents. The extractable material that lines the cells ofTrachusa byssina, in contrast, is derived fromPinus resin, to which it can be chemically traced.