Department of Mathematics and Biomathematics Graduate Program, North Carolina State University, Raleigh, 27695, USA.
J Med Entomol. 2012 Nov;49(6):1177-88. doi: 10.1603/me11205.
We demonstrate the utility of models as aids in the design and development of experiments aimed at measuring the effects of proposed vector population control strategies. We describe the exploration of a stochastic, age-structured model that simulates field cage experiments that test the ability of a female-killing strain of the mosquito Aedes aegypti (L.) to suppress a wild-type population. Model output predicts that choices of release ratio and population size can impact mean extinction time and variability in extinction time among experiments. We find that unless fitness costs are >80% they will not be detectable in experiments with high release ratios. At lower release ratios, the predicted length of the experiment increases significantly for fitness costs >20%. Experiments with small populations may more accurately reflect field conditions, but extinction can occur even in the absence of a functional female-killing construct because of stochastic effects. We illustrate how the model can be used to explore experimental designs that aim to study the impact of density dependence and immigration; predictions indicate that cage population eradication may not always be obtainable in an operationally realistic time frame. We propose a method to predict the extinction time of a cage population based on the rate of population reduction with the goal of shortening the duration of the experiment. We discuss the model as a tool for exploring and assessing the utility of a wider range of scenarios than would be feasible to test experimentally because of financial and temporal restraints.
我们展示了模型在设计和开发旨在测量拟议的向量种群控制策略的效果的实验中的辅助作用。我们描述了对随机、年龄结构模型的探索,该模型模拟了野外笼式实验,以测试埃及伊蚊(Aedes aegypti(L.))雌性致死品系控制野生种群的能力。模型输出预测,释放比例和种群大小的选择会影响实验中平均灭绝时间和灭绝时间的可变性。我们发现,除非适应度成本超过 80%,否则在高释放比例的实验中无法检测到这些成本。在较低的释放比例下,对于适应度成本超过 20%的情况,预测的实验长度会显著增加。种群较小的实验可能更能反映野外条件,但由于随机效应,即使没有功能性雌性致死构建体,灭绝也可能发生。我们说明了如何使用模型来探索旨在研究密度依赖和移民影响的实验设计;预测表明,在操作上可行的时间框架内,笼式种群根除可能并不总是可行的。我们提出了一种基于种群减少率来预测笼式种群灭绝时间的方法,旨在缩短实验的持续时间。我们讨论了该模型作为一种工具,用于探索和评估比由于财务和时间限制而在实验中可行的范围更广泛的情景的效用。