Insecticidal effects on cowpea aphids and their parasitoids, blue alfalfa aphids, and alfalfa weevils in 2002

Abstract

Twentynine insecticide treatments were applied on Feb. 7, 2002, to evaluate the effects of chemistry and rates on cowpea aphids and associated parasitic wasps. Data were also able to be collected on blue alfalfa aphids and alfalfa weevil larvae. At seven days post treatment fewest cowpea aphids were noted in plots treated with Furadan, the 3.84 oz./acre rate of WarriorT, and several of the higher rates of Lorsban 4E. Organophosphate insecticides had fewer cowpea aphids on the whole than did pyrethroid insecticides. All insecticide treatments had significantly fewer parasitic wasps than the untreated check, although these populations may correspond to aphid populations. All insecticide treatments had fewer blue alfalfa aphids early in the study, with very good control noted from the 3.84 oz./acre rate of WarriorT and the combination of 8 oz. of Lorsban 4E + 2 oz./acre of Baythroid 2. Treatments containing Baythroid 2 had the fewest blue alfalfa aphids at 44 days post treatment. Treatments which had at least 70% fewer weevils than the untreated check at 12 days post treatment included Furadan, all treatments that included any formulation of Baythroid, and the high rates of WarriorT and Pounce 3.2 EC, and the 0.088 rate of F1785 50DF.