Individually recognizable scent marks on flowers made by a solitary bee

The marking of flowers with ephemeral scent is an underappreciated but vita l element in the foraging behaviour of social bees. Using observational and experimental data, we tested whether a solitary bee (female Anthophora plu mipes) uses scent marking while foraging on flowers of Cerinthe major in Po rtugal. Females used scent marks with at least two components that differed in their volatility and, furthermore, recognized the marks of different in dividuals. A very short-term component (<3 min) was attractive, resulting i n the observed high level of immediate revisits: this component appeared to be adjusted according to the foraging needs of the moment. A longer-term c omponent (<30 min) was initially repellent and matched the rate of nectar r enewal; it, or the response to it, also appeared to be adjusted to the perc eived level of nectar reward. There may be even longer-term effects associa ted with the specific foraging areas of individual bees. Observed differenc es in the way in which individuals responded to scent marks indicate that t hey may play a role as part of a dominance or exclusion mechanism among fem ales. (C) 2001 The Association for the Study of Animal Behaviour.