Investigation of the occurrence dynamics of Evergestis extimalis

Key Words：Evergestis extimalis, occurrence dynamics, investigation

Abstract：     The investigation showed that the overwintering larvae Evergestis extimalis Scopoli pupated from early June in the rape fields of Qinghai. The pupation rate was 80% in midJune, and 100% in late June. Adults emerged from early July, and it reached the peak on 15th～20th of July. From late June to early July, females began laying eggs, and it reached the peak in midJuly. The average mortality of overwintering larvae was 96.63% result shown that in the rape planted fields via and study.