Sexual Sterilization of Tobacco Budworms with Combinations of Oral Chemosterilants and Gamma Irradiation12

Abstract

When the antimetabolites sulphanilamide, dicumarol [3,3'-methylenebis(4-hydroxycoumarin)], 2-imidazolidinethione and imidazole and the plant hormone beta -sitosterol were incorporated separately into the larval diet of Heliothis virescens (F.) to give substerile concentrations of 0.01-0.1%, and resultant pupae were exposed to gamma -radiation from radioactive cobalt (60Co) at doses of 7.5 and 15 krad in laboratory tests in Texas, no chemical or radiation treatment alone was as effective as any of the combinations in producing sterile adults, and none of the combinations affected larval development, adult emergence, or adult life span. Although the fecundity of treated females was reduced, the number of matings per female was lower only when the male was the treated member of a mating pair