[eng] We experimentally demonstrate that optical pulses emitted by a semiconductor-based polarization-maintaining figure-of-eight fiber laser are temporal localized structures that can be individually switched on and off by means of optical reinjection of single pulses at different delay times. We also explore the formation of an equispaced cluster of localized structures that can be interpreted as a portion of an underlying periodic pattern¿the harmonic state¿and we provide a basic theoretical scenario for explaining the observations.