Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.
Department of Entomology, Federal University of Viçosa, Minas Gerais, Brazil.
Ecol Lett. 2021 Sep;24(9):2010-2024. doi: 10.1111/ele.13819. Epub 2021 Jun 23.
Chemical pesticides remain the main agents for control of arthropod crop pests despite increased concern for their side effects. Although chemical pesticide applications generally result in short-term decreases of pest densities, densities can subsequently resurge to higher levels than before. Thus, pesticide effects on pest densities beyond a single pest generation may vary, but they have not been reviewed in a systematic manner. Using mathematical predator-prey models, we show that pest resurgence is expected when effective natural enemies are present, even when they are less sensitive to pesticides than the pest. Model simulations over multiple pest generations predict that pest resurgence due to pesticide applications will increase average pest densities throughout a growing season when effective natural enemies are present. We tested this prediction with a meta-analysis of published data of field experiments that compared effects of chemical control of arthropod plant pests in the presence and absence of natural enemies. This largely confirmed our prediction: overall, pesticide applications did not reduce pest densities significantly when natural enemies were present, which concerned the vast majority of cases. We also show that long-term pesticide effectiveness is underreported and suggest that pest control by natural enemies deserves more attention.
尽管人们越来越关注化学农药的副作用，但化学农药仍然是防治节肢动物作物害虫的主要手段。尽管化学农药的使用通常会导致短期内害虫密度降低，但随后害虫密度可能会回升到比以前更高的水平。因此，化学农药对单一害虫世代以外的害虫密度的影响可能会有所不同，但尚未以系统的方式进行审查。我们使用数学捕食者-猎物模型表明，即使有效天敌对农药的敏感度低于害虫，在存在有效天敌的情况下，也会预期害虫再次出现。对多个害虫世代的模型模拟预测，当存在有效天敌时，由于农药的使用，害虫在整个生长季节的平均密度将会增加。我们用对已发表的田间实验数据的荟萃分析来检验这一预测，这些实验比较了在有和没有天敌的情况下，对节肢动物植物害虫进行化学防治的效果。这在很大程度上证实了我们的预测：总体而言，当存在天敌时，农药的使用并不能显著降低害虫密度，而这种情况在绝大多数情况下都存在。我们还表明，长期的农药有效性被低估了，并建议应更多地关注利用天敌进行害虫防治。
