EFFECTS OF SUBLETHAL DOSES OF 2 INSECT GROWTH-REGULATORS ON HELICOVERPA-ZEA (LEPIDOPTERA, NOCTUIDAE) REPRODUCTION

The effects of sublethal doses of two insect growth regulators on Heli coverpa zea (Boddie) reproduction were investigated. Adults which deve loped from larvae that fed on a pinto bean diet containing diflubenzur on (Dimilin) or an ecdysone agonist (RH 5992) were inbred and outcross ed with adults which developed from larvae that were fed on a normal p into bean diet. Data were collected on fecundity, fertility, and sperm transfer. Sublethal doses of both compounds administered to H. zea la rvae caused reduced fertility in surviving male imagos but had no effe ct on fecundity or fertility of the female imagos. Reduced fertility i n treated males was largely caused by a lower incidence of sperm trans fer. Implications of our results for H. zea population management are discussed.