Identification of Sterile Backcross Heliothis Males in Field Collections

Hybridization of Heliothis virescens (F.) males with Heliothis subflexa (Cuennée) females followed by back crossing of the female progeny to H. virescens males produces a backcross (BC) line consisting of fertile females and sterile males each generation. A rapid cytological method for distinguishing between sterile BC Heliothis males and fertile native males is presented. The method requires no fixing or staining of tissues. Application of this technique in future Heliothis suppression programs involving release of sterile BC insects is discussed.