The present work aimed to evaluate the efficiency of three insecticides [indoxacarb (Avaunt 15% EC), lufenuron (Match 5% EC) and methoxyfenozide (Runner 24% SC)] at their recommended rates at two different spray times of 10 or 15 days after the first spray against potato tuber moth (PTM), Phthorimaea operculella (Zeller) larvae on two potato varieties (Spunta and Mondial) during two successive summer seasons 2014 and 2015 at Appig village, Kafer El-zyaat center, Gharbia Governorate, Egypt. A randomized complete block design was applied for treatments including untreated check. The results showed that for 10 days experiments at season 2014, all treatments achieved reduction of PTM population in the foliage infestation when the highest values were recorded with Avaunt (46.29% & 41.97%) followed by Runner (34.84 % & 28.10 %) and Match (33.04% & 26.53%), for Spunta and Mondial varieties, respectively. The same trend was also recorded during the season of 2015. However, for 15 days experiments during season 2014, all treatments showed reduction of PTM population in the foliage infestation when the highest values were recorded with Avaunt (54.46% & 61.41%) followed by Runner (47.01 % & 47.47 %) and Match (41.18% & 44.51%), for Spunta and Mondial varieties, respectively. The same trend was also recorded at season 2015. Generally, all treatments achieved reduction of PTM population in the foliage infestation and resulted in increasing the potato yield of two varieties compared with untreated check. Fifteen days experiments were more appropriate than ten days where, Spunta variety was more susceptible to foliage infestation than Mondial variety.