Interspecific hybridization of Helicoverpa armigera and H-assulta (Lepidoptera: Noctuidae)

Reciprocal hybridization between Helicoverpa armigera (Hubner) and H. assulta Guenee followed by backcrossing of the hybrids (F-1) with H. armigera produced backcross (BC) lines consisting of fertile females and males. The Fl of H. armigera female and H. assulta male had only male, no female sex. In this case Haldane's rule applies, and therefore it is proved that the sex chromosomes of Helicoverpa species are of ZW type, and the female is the heterozygous sex. This hybrid also showed significant heterosis with the heaviest pupal weight, and when it was backcrossed with H. armigera female, the sex ratio of the BC offspring was distorted as 1 : 4. The potential utilization of this hybrid in genetic controlling H, armigera was finally discussed.