The impacts of climatic factors are the differences in temperature, humidity and precipitations, especially in spring and autumn season. They are creating deviations in the preferable host species of H. armigera. These variations can modify a ethology of this pest, whose development is associated with choosing habitats for larval nutrition. Climatic factors of the vegetation period in 2016 in Moldova were characterized by a variety of precipitation and average temperature of the season. Exceeding the average air temperature by 1,5-2,4°C above the norm (20,8-23,0°C) is noted once in 10 years, in the whole period of observations. The revaluation of ethological peculiarities of pest H. armigera in the conditions of changing climate factors demonstrated that there is an extension of the period of activity. The beginning of the first generation activity started 15 days earlier and the third generation flight extended by 30 days.