  We have studied spectral diffusion of the photoluminescence of a single CdSe
quantum dot inserted in a ZnSe nanowire. We have measured the characteristic
diffusion time as a function of pumping power and temperature using a recently
developed technique [G. Sallen et al, Nature Photon. \textbf{4}, 696 (2010)]
that offers subnanosecond resolution. These data are consistent with a model
where only a \emph{single} carrier wanders around in traps located in the
vicinity of the quantum dot.
