The causes and consequences of spatial heterogeneity in population dynamics are of both theoretical and practical interest. Previously, we described (Kummel et al., Oikos 122:896–906, 2013) a field system in which predation by ladybugs drives the development of strong spatial heterogeneity among aphid populations living on nearby plants. In this paper, we investigate the detailed mechanisms responsible for this phenomenon. We develop a detailed mathematical model of the system, parameterized by an extensive experimental work showing that ladybugs tend to remain on plants with high aphid numbers and are attracted to plants on which ladybugs are actively feeding. The model reproduces important aspects of the field system and allows us to explore how various behavioral features contribute to these dynamics. The results indicate that spatial heterogeneity results from the random aspect of ladybug foraging that causes some large aphid populations to be under-exploited. For parameter values that are unrealistic for our system, the model displays other types of complex dynamics, including predator swarming and chaos. Our study illustrates how a realistic, carefully parameterized model can connect individual behavior to larger scale spatiotemporal dynamics.

人口动力学中空间异质性的原因和后果在理论上和实践上都具有重大意义。之前，我们描述了（Kummel等人，Oikos 122：896-906，2013）一个田间系统，其中瓢虫的捕食推动了生活在附近植物上的蚜虫种群中强烈的空间异质性的发展。在本文中，我们研究了造成这种现象的详细机制。我们开发了一个详细的系统数学模型，并通过大量的实验工作进行了参数化表明，瓢虫倾向于留在蚜虫数量高的植物上，并被瓢虫正在积极觅食的植物所吸引。该模型再现了现场系统的重要方面，并使我们能够探索各种行为特征如何促进这些动态。结果表明，空间异质性是由瓢虫觅食的随机方面导致的，该随机方面导致一些大型蚜虫种群未被充分利用。对于对于我们的系统而言不切实际的参数值，模型将显示其他类型的复杂动力学，包括捕食者蜂拥而至和混乱。我们的研究说明了一个现实的，经过仔细参数化的模型如何将个体行为与更大的时空动力学联系起来。