Comparative pattern of emergence of Heliothis zea and H. virescens (Lepidoptera: Noctuidae) from overwintering pupae

Mean Julian day for emergence from overwintering of tobacco budworms (TBW), H. virescen (F.), was ca. 9 days earlier than that for bollworms (BW), H. zea (Boddie), in a plot of pigeon peas, Cajanus cajan L., in central Texas in 1980-1981. Females of both species emerged 4 or 5 days earlier than males. Synchrony between the spring emergence of male TBW and their capture in pheromone traps demonstrated the feasibility of using pheromone traps to monitor overwintering emergence. On the other hand, asynchrony between the capture and emergence of BW males indicated that movement of the species into the area may occur before emergence from overwintering.