Quantity of components of the labial gland secretion of bumblebees changes significantly during the lifetime of males. Six compounds in B. terrestris and 9 components in B. lucorum elicited antennal responses of virgin queens.
In both species, concentrations of active compounds reached their maximum (milligrams) on seventh day after eclosion. Subsequently, a rapid decrease in the amounts of active compounds occurred in B. terrestris, whereas in B. lucorum the amounts stayed approximately constant or decreased at a slow rate.