Banker plant systems are designed to decouple predator-prey interactions so natural enemies can reproduce and survive even when pest populations are low. Banker plant systems consist of three basic components: banker plant, alternative food or host, and a predator or parasitoid that are implemented in a particular crop and production system. Our objective is to determine how each of these factors influences trophic interactions to optimize biological control efficacy.
Banker plant systems for biological control of aphids
Banker plant systems to control aphids consist of a cereal plant, such as wheat, infested with bird cherry-oat aphids (BCOA), Rhopalsiphum padi L. (Hemiptera: Aphididae). BCOA only feed on grasses and thus will not be a pest of most ornamental crops. However, BCOA are attacked by the same parasitoid wasp, Aphidius colemani, that attacks many pest aphids such as green peach aphid (Myzus pericae) and cotton aphid (Aphis gossypii). In this banker plant system, A. colemani parasitizes BCOA which live on banker plants and pests that infest crop plants. Therefore, the parasitoid can reproduce and patrol the greenhouse even when no pests are present.
MS student Sara Prado is investigating A. colemani host choice when reared on banker plants vs. crop plants to determine if parasitoids emerging from banker plants will forage in the crop for pests or just return to alternative hosts on banker plants. She is also testing the efficacy of banker plants compared to augmentative releases of parasitoids in large greenhouse experiments.
Banker plant systems for biological control of thrips
A banker plant system for biological control of thrips used the ‘Black Pearl’ pepper plant to provide pollen for the minute pirate bug, Orius insidiosus. MS student Sarah Wong has found that pollen from ‘Black Pearl’ pepper increases O. insidiosus survival and abundance without reducing predation of thrips. This system show promise for increase O. insidiosus abundance in greenhouse to improve thrips management.