Insecticide Resistance in Heliothis Armigera (Hübner) (Lepidoptera: Noctuidae) in Areas of Queensland, Australia

Testing of Heliothis armigera larvae by topical application during 1973‐74 and 1974‐75 showed high levels of resistance to DDT in strains from Brookstead (>100‐fold), Bowen (>100‐fold), St. George (97‐fold) and Capella (66‐fold). Lower levels of resistance were shown in strains from Mareeba (37‐fold), Bundaberg (22‐fold), Redland Bay (30‐fold) and Cambooya (15‐fold). The Capella and St. George strains were less susceptible to DDT + camphechlor than the Brookstead strain, but resistance to this insecticide mixture was not considered to have been proven. The St. George strain was 21 times more resistant to endosulfan than the Brookstead strain. No evidence of resistance to parathion‐methyl was demonstrated. Two strains of H. punctigera showed no resistance to DDT.