Release of Sterile Backcross Moths During 1993 in a Pilot Program to Control the Tobacco Budworm

M. L. Laster, D. D. Hardee, and J. C. Schneider


The second and final release in a pilot program was made in 1993 to test the feasibility of suppressing the tobacco budworm, Heliothis virescens (F.) (HV), in an agricultural production environment by releasing sterile backcross (BC) insects over a wide area. The control area for the 1992 release was used for the 1993 release area, and approximately 70,278 BC moths per day emerged from pupae placed in the field beginning 12 April to 25 May. The moths dispersed from 25 release points spaced about 3.2 km apart in a square area 16 km on each side. Moth captures in pheromone traps indicated that a 1.0:1.3 released:wild ratio was achieved during the release period. When wild BC (estimated from the testing of a subsample of trapped males for sterility) was combined with released BC, a 2.6:1.0 BC:HV ratio was indicated for the release period. This ratio decreased to 1.0:1.6, 1.0:3.6, and 1.0:4.0 during June, July, and August following the release. The ratio of BC:HV in the control area resulting from the 1992 release (with some possible early reproduction in 1993) was 1.0:2.2 during the release period. This ratio decreased to 1.0:5.2 BC:HV in June following the release and increased to 1.0:4.7 and 1.0:3.4 for July and August, respectively. High winter survival of the BC trait could be important to the success of suppressing HV populations by future area-wide releases of BC insects.

Reprinted from Proceedings of the 1994 Beltwide Cotton Conferences pp. 925 - 927
©National Cotton Council, Memphis TN

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Document last modified Sunday, Dec 6 1998