Large-scale Rearing of a Sterile Backcross of the Tobacco Budworm (Lepidoptera: Noctuidae)1

Abstract

From 1978 to 1982, 10,265,083 pupae were reared in support of the USDA-ARS pilot test “Management of tobacco budworm with hybrid sterility.” Most pupae were shipped to the test site (St. Croix, U.S. Virgin Islands), where the sterile backcross (BC), tobacco budworm (TBW) ( Heliothis virescens [F.]) male × BC female from the intercross TBW male × H. subflexa (Guenee) female was released for suppression of the TBW population. During a span of 117 consecutive days in late 1980, 5,713,245 BC pupae were shipped to St. Croix at the rate of 48,831 pupae per day. Moth emergence from pupae after shipment was 88 ± 5%; 7 ± 7% of the adults were deformed. Interaction of laboratory-reared moths with the feral population was verified by increase of sterility in feral TBW females, increase in percentage of feral males transferring only apyrene sperm, and consequent population suppression. Facilities at Stoneville were modified for maintaining BC and TBW brood colonies as well as large-scale rearing of the BC. Consistent production of high-quality insects required implementation of rigid protocols for larval rearing, moth holding, and egg collection and infesting of diet, pupal harvesting and shipment, and sanitation. Mass production of Heliothis spp., and the TBW sterile BC, specifically, requires automated rearing procedures as well as expanded facilities if areawide population suppression of TBW on the United States mainland is attempted.