Observations on the Nesting Habits of Some New World Carpenter Bees with Remarks on their Importance in the Problem of Species Formation (Hymenoptera: Apoidea)

The biological literature pertaining to the nesting habits of the New World carpenter bees belonging to the genus Xylocopa is organized and new biological information, particularly that relating to the nesting habits, is provided for eight American species. These are: Xylocopa augusti Lepeletier, X. brasilianorum varipuncta Patton, X. californica arizonensis Cresson, X. frontalis (Olivier), X. guatemalensis Cockerell ( X. peleni Cockerell is declared a synonym), X. micans Lepeletier, X. tabaniformis androleuca Michener, and X. virginica virginica (Linnaeus). The importance of nesting habits in determining the probable ancestry, origin, dispersal and species formation in the group is discussed and evaluated. The accidental introduction of carpenter bees and their occasional successful establishment in new geographic areas is explored with the conclusion that care should be taken so as to prevent accidental introductions of species known to attack structural timbers.