Demographic Evaluation of the Control Potential of Orius minutus (Hemiptera: Anthocoridae) Preying on Dendrothrips minowai Priesner (Thysanoptera: Thripidae) at Different Temperatures

Simple Summary Orius minutus (Hemiptera: Anthocoridae) has been used as an effective biological control agent (BCA) for many thrips pest in different crops. However, its predating ability on tea thrips, a major pest in tea garden, has not yet been discerned. Meanwhile the effect of temperature on their biology and interaction is unknown. We here first evaluated the population development of this predator interaction with pests by using age-stage, two-sex life tables analysis under a range of constant environmental conditions. We proved that the minute pirate bug could effectively control the population development of tea thrips under intermediate temperatures (20-25 degrees C). Both predator and pest were extremely vulnerable at 35 degrees C. The present result might be used to predicate the population dynamics and downstream applications for O. minutus as BCA against tea thrips in tea plantation. Tea thrips (Dendrothrips minowai Priesner) are the main pests that seriously affect the yield and quality of tea, resulting in huge economic losses. The Orius minutus is one of the most important natural enemies or BCA of thrips. However, we are not concerned with its predation ability on tea thrips, nor thermal influence on this pattern and their interaction. Therefore, this study recorded life table data of O. minutus and tea thrips combined with predation rate data to assess the ability of O. minutus to control tea thrips using age-stage, two-sex life tables at five constant temperatures. The results showed that at 25 degrees C, O. minutus had the highest predation rate on tea thrips, with an average generation time (T) of 22 d, intrinsic rate of increase (r) of 0.12 d-1, fecundity of 64.17, net reproduction rate (R-0) of 12.76 offspring, and net predation rate (c(0)) of 310.92. In addition, around 410,000 adults and 1.98 million eggs were produced within 120 days. While the temperature change was straightforward, temperature effects on insects are not linear. The population size of the O. minutus and tea thrip trended similarly at 15-30 degrees C and would eliminate dramatically at 35 degrees C. Meanwhile, the results indicated that O. minutus could effectively inhibit the population growth of tea thrips at 15-30 degrees C, within 5-19 days at an intervention ratio of 10 adult O. minutus and 200 thrips individuals. The simulations under different mediated temperatures demonstrated that O. minutus is effective against tea thrips over a wide temperature range expected to be potential for biocontrol of tea thrips in tea gardens.