Abstract
Conventional paraffinic base oils were superior to naphthenic and alkylate isoparaffinic oil fractions for control of the corn earworm,Heliothis zea (Boddie), when combined with DDT and a Heliothis polyhedral virus. The greater rates of oil per acre and oils which had molecular weights of 280-360 and viscosities of 50-125 Saybolt increased earworm control. Oils alone did not appear to increase corn earwonn control. It is suggested that oils increase the effectiveness of DDT and a Heliothis polyhedral virus primarily as carriers of these control agents along the silk channel. DDT (1962-63) appears to be less effective than previous data (1950-61) indicate.