Effect of native natural enemies and augmentative releases ofChrysoperla rufilabrisBurmeister andAphidoletes aphidimyza(Rondani) on the population dynamics of the green apple aphid,Aphis poMiDe Geer

Abstract

Abstract The impact of native natural enemies, supplemented by augmentative releases of the green lacewing, Chrysoperia rufilabris Burmeister (Neuroptera: Chrysopidae), and/or the cecidomyiid, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), on the population dynamics of the green apple aphid, Aphis pomi De Geer (Homoptera: Aphididae), was assessed in a series of experiments conducted in north central Washington State, USA. In one trial, C. rufiabris alone was released at a rate of 200 eggs or first instar larvae per tree per week for 6 weeks; in a second experiment, it was released in combination with A. aphidimyza at rates of 400 eggs and 250 pupae respectively per tree per week. In a final trial, A. aphidimyza alone was released at a rate of 200 pupae per tree per week for the duration of the growing season. The dominant native natural enemies in the study area were Chrysopa nigricornis Burmeister, A. aphidimyza. Onus sp. (Hemiptera: Anthocoridae), and various species of Syrphidae, Chamaemyii...