Evaluation of Eleven Plant Species as Potential Banker Plants to Support Predatory Orius sauteri in Tea Plant Systems.

Abstract

Simple SummaryThe tea plant is an economically significant beverage crop globally, especially in China. However, tea green leafhoppers and thrips are key pests in Asian tea production systems, causing serious damage to its yield and quality. With growing concerns about pesticide residues on tea and their adverse effects on natural enemies of tea pests, biological pest control is gaining more importance in tea plantations. Orius sauteri is a polyphagous predator used as a biological control agent. Here, we reported 11 plants as banker plants to support the predatory Orius sauteri in tea plant systems. Among them, white clover, red bean, mung bean, peanut, soybean, kidney bean, bush vetch, smooth vetch, and common vetch were found suitable; red bean performed relatively better than the others. Tea green leafhoppers and thrips are key pests in tea plantations and have widely invaded those of Asian origin. Pesticides are currently a favorable control method but not desirable for frequent use on tea plants. To meet Integrated Pest Management (IPM) demand, biological control with a natural enemy is viewed as the most promising way. Orius sauteri are slated to be a natural enemy to tea pests. However, more knowledge of rearing O. sauteri and selecting banker plant systems is strongly needed. The reproductive biology evaluation of the egg oviposition and population life parameters of O. sauteri under laboratory conditions were examined, and the supporting ability of 11 plant species—motherwort, white clover, red bean, mung bean, peanut, soybean, kidney bean, herba violae, bush vetch, smooth vetch, and common vetch—in a greenhouse was assessed. Most of the selected plants, except for herba violae, performed relatively well with high oviposition quantity and survival. The mean fecundity per female on red bean and motherwort was 148.75 eggs and 148.25 eggs, respectively, and 90.20 eggs for tea plants (the smallest); there also were significant differences. In an experiment to determine the life parameters of O. sauteri, all the tested plants, except herba violae, were found to be able to complete the growth and development of the life cycle; there also were significant differences. The intrinsic rate of increase of motherwort and red bean was 1.18 and 1.17, respectively, and higher compared to that of the other plants, including tea plants (1.13). This result of the O. sauteri population development index was also confirmed in a greenhouse with the number of motherwort and red beans being as high as 113.33 and 112.67. Since motherwort was found to be susceptible to aphids and powdery mildew in each trial, it cannot be used for intercropping in tea gardens. Among the 11 plants, red bean was found to be the most suitable to support O. sauteri in tea plantations.