The diurnal and seasonal behavior of the depletions in the ionospheric electron content, associated with amplitude scintillations measured at Arequipa, Peru for about one year around the recent solar maximum period, are presented. The seasonal variation shows asymmetrical equinoctial maxima, the February--April period having marked higher occurrences. Amplitude scintillation measurements at 1.54 GHz and 257 MHz at the nearby magnetic equatorial station Huancayo, Peru also show a similar pattern. A comparison of the three sets of data indicates the simultaneous development of irregularities of different scale sizes and earlier erosion of the smaller scale irregularities.