Collaborative Research: An Experimental and Theoretical Study of the Ecology of the Control of Red Scale by Aphytis

利用柑橘天牛寄生蜂防治柑橘树上的赤眼病是生物防治的一个典型例子，它能产生稳定的交互作用。我们已经测试并拒绝了八个试图解释此类系统稳定性的假设。我们已经证明，一种机制，即空间避难所，实际上会降低稳定性。我们将采用模拟和田间实验相结合的方法，研究其他三种潜在的稳定机制的作用：成虫处于不受伤害的成虫阶段，以及大小相关的性别分配和非植物种的寄主取食。使用同样的方法，我们还将探索空间避难所的动态影响，并将开始评估一种小型寄生蜂Encarsia的影响。我们的研究将为影响捕食-被捕食系统动力学的机制提供一般的生态学见解，将扩展一般的生态学理论和现实模型的开发和测试，并将有助于阐明成功的生物防治的特征。

Control of the insect pest, red scale, on citrus trees by the parasitoid Aphytis melinus is a classic example of biological control resulting in a stable interaction. We have tested and rejected eight hypotheses seeking to explain stability in such systems. We have demonstrated that one mechanism, a spatial refuge, actually decreases stability. Using a combination of modelling and field experimentation, we will investigate the role of three other potential stabilizing mechanisms: the presence of an invulnerable adult stage of scale, and size-dependent sex- allocation and host-feeding by Aphytis. Using the same approach we will also explore the dynamic effects of the spatial refuge and will begin evaluating the effects of a minor parasitoid, Encarsia. Our research will provide general ecological insight into the mechanisms influencing the dynamics of predator-prey systems, will extend both general ecological theory and the development and testing of realistic models, and will help elucidate the distinguishing features of successful biological control.