Suppression of Feral Helicoverpa zea (Lepidoptera: Noctuidae) Populations Following the Infusion of Inherited Sterility from Released Substerile Males

A pilot test was conducted in small mountain valleys from 1986 through 1990 in western North Carolina to assess the influence of released, substerilized males on wild populations of Helicoverpa zea (Boddie), and to measure the level of inherited sterility in wild populations. The number of wild males captured per ha was positively correlated with the distance from the release site of irradiated males. Analyses of seasonal population curves of wild H. zea males calculated from mark-recapture data suggest that seasonal increases of wild H. zea males were significantly delayed or reduced (or both) in mountain valleys where irradiated males were released. The incidence of larvae with chromosomal aberrations (progeny of irradiated, released males) collected from the testsites during the growing seasons indicated that irradiated males were competitive with wild males in mating with wild females, and were successful in producing F 1 progeny which further reduced the wild population.