The impact of boll weevil eradication on seasonal activity of bollworm, Helicoverpa zea (Boddie), tobacco budworm, Heliothis virescens (F.), and beet armyworm, Spodoptera exigua (Hübner), moths was evaluated in the Rolling Plains of Texas during 1996-1999. The central Rolling Plains eradication zone received several applications of ULV malathion during the fall of 1996 and 1997 and full-season applications in 1998 and 1999 based on predetermined threshold of two boll weevils per trap. The northern Rolling Plains was not under eradication program during the survey period. Moth activity was monitored weekly in both eradication and noneradication zones using sex pheromone traps; surveys were conducted from early April to mid-October every year. Average abundances of all moth species were similar between eradication and noneradication zones during preeradication (1996). Abundances of bollworm and tobacco budworm moths during the active eradication phase did not vary between eradication and noneradication zones, indicating no significant impact of boll weevil eradication on these moths. In contrast, boll weevil eradication significantly increased the beet armyworm moth activity. However, the influence of boll weevil eradication on beet armyworm moth activity was significant only during the first two years following the initiation of eradication. This suggests that the impact of boll weevil eradication on beet armyworms occurs during the active eradication phase and the impact tends to diminish during the posteradication maintenance phase.