Establishment of a Faba Bean Banker Plant System with Predator Orius strigicollis for the Control of Thrips Dendrothrips minowai on Tea Plants under Laboratory Conditions

SIMPLE SUMMARY: The banker plant system may provide an effective and economical method for long-term suppression of insect pests. We developed a non-crop banker plant system aiming to improve the control of stick tea thrips Dendrothrips minowai in tea plantations. In this system, we used the polyphagous predator Orius strigicollis (Poppius) as the biocontrol agent, the black bean aphid Aphis fabae (Scopoli) as an alternative food, and the faba bean Vicia faba L. as the banker plant to support the predator in controlling pest thrips. Laboratory tests revealed that the control efficacy of the banker plant system was higher than that of directly releasing O. strigicollis. These results indicate that this banker plant system may be used in the field to provide a more effective and economical way to control pest thrips in tea plantations compared with the direct release of O. strigicollis. ABSTRACT: The stick tea thrip Dendrothrips minowai (Priesner) (Thysanoptera: Thripidae) is a destructive pest in tea plantations in south and southwest China. To control this pest, a non-crop banker plant system was developed using a polyphagous predator Orius strigicollis (Poppius) (Heteroptera: Anthocoridae) with the black bean aphid Aphis fabae (Scopoli) (Hemiptera: Aphididae) as an alternative prey and the faba bean Vicia faba as the banker plant to support the predator in targeting the pest. The fitness of A. fabae on tea plants and faba bean was evaluated to determine its host specificity. Moreover, the control efficacy of the banker plant system on D. minowai on tea plants was tested in the laboratory and compared with that of direct release of O. strigicollis. The experiments showed that faba bean was an excellent non-crop host for A. fabae because, while the aphid population increased quickly on faba bean, it could only survive for up to 9 days on tea plants. Compared with direct release of O. strigicollis, lower densities of pest were observed when introducing the banker plant system. Our results indicate that this banker plant system has the potential to be implemented in the field to improve the control of the pest thrips.