The study set out to ascertain how the number of generations of Earias insulana (Boisd.) moths would be affected by rising temperatures in 2050, 2075, and 2100. The Sharkyia Governorate was the site of a four-year comparative field research conducted between 2019 and 2022 in order to achieve this goal. There were nine field generations recorded. The generations and peak-to-peak, general average durations were 39.0±17 and 36±11 days, respectively, with a coefficient variance CV of 43.0 and 30.4 days. The overall average for thermal heat units was 507± 6 and 520± 19 units, while the CV values were 1.2 and 3.6 days. The estimated average duration of a generation for the years 2050–2100 was 32–34 days, with 11–13 day standard deviation. Compared to the field study, the CV values were 34.9–37.2 days lower. Due to a shorter generation growth period in the anticipated years than in the field research, the generations will occur earlier. The thermal constant remained nearly constant throughout generations and from peak to peak, even though the year's thermal units increased from 4595 units in the average of four years of field study to 5207, 5418, and 5595 units in the anticipated years 2050, 2075, and 2100, respectively. Nine generations of E. insulana moths were recorded in 2019–2022, rising to ten in 2050, remaining at ten in 2075, and reaching eleven in 2100. The number of days required to complete the generation growth is clearly correlated with temperature; the generation period decreases with increasing temperature.