Evaluation of the possibility of using banker plant to increase parasitism of Aphis gossypii by a parasitoid wasp, Lysiphlebus fabarum

In parasitoids, host recognition and host preference strongly affect offspring fitness. These behavioral features are important in biological control when using the banker plant method. The use of banker plants (Vicia faba infected by Aphis fabae) in the presence of Lysiphlebus fabarum (Braconidae: Aphidiinae) was investigated as a way to control Aphis gossypii on cucumber plants. Synchronous wasp cohorts were produced on A. fabae or A. gossypii, then the mated females emerging from each aphid species were individually released into a petri dish containing 15 A. fabae and 15 A. gossypii (second-instar), to determine the impact of the host species of the parents on the fitness of the emerging adult parasitoids. The female wasps parasitized a larger percentage of available A. gossypii than A. fabae, and in addition, the females reared on A. gossypii were significantly larger than females reared on A. fabae. The results revealed that reducing the preference of A. fabae as an alternative host by L. fabarum led to an increase in parasitism of the pest aphid A. gossypii.