Long-term evolution of the prominence spicules that exhibit quasi-periodic propagating intensity disturbances in a diffused prominence. Plotted for the observations obtained on 2016 May 30 (see Fig. A.1a). Top panel: AIA 171 Å light curves averaged along the sections of the same colored slits as in Fig. A.1a. Bottom panel: space-time map displaying propagating disturbances along slit a–b. See Appendices B.2 and D.