Studies on the biology of A. ypsilon Rott. were conductedin laboratory at Peshawar. The first generation starting with moths caught at light in early April completed in May. The subsequent 3 generations completed in June, Augeust and September and the last hibernated during winter. The average duration of pre-oviposition, incubation, larvae and pupae were 2.3, 3.95, 3.6, 22.16, and 10.54 days, respectively. In usceptibility test of A. ypsilon and A. segetum to G. V. from Denmark conducted in laboratory, 100% mortality of both species was observed due to virus infection while 62% and 63% larvae of A. segetum and A. ypsilon. Pupated successfully in check treatment.