Pesticides threaten biodiversity, but we know little about how they permeate food webs. Few studies have investigated the number, concentration, and composition of pesticides in agroecosystem food webs even though agroecosystems cover one-third of Earth’s land area. We conducted a pioneering study on the distribution of pesticides across local (i.e., on farm) and meta food webs (i.e., regional pool of local food webs) within both perennial (N = 8) and annual crops (N = 11), examining four trophic groups—soil (primary resource), plants (primary producers), rodents (herbivores), and spiders (predators)—for the presence of multiple residues, and comparing these findings to pesticides applied by farmers in recent years. We also undertook interviews with farmers to obtain the most precise information about pesticide applications in their fields. We detected a wide spectrum of pesticides in both annual and perennial crop types. Pesticides applied by farmers represented only a small proportion of all detected pesticides, indicating that pesticides entered local food webs from surrounding landscapes. Some detected pesticides had been banned by the European Union several years ago, which is highly alarming. Trophic group mobility and crop type drove pesticides number at local scale, as mobile groups contained larger numbers of pesticides (probably from encountering wider spectra of pesticides). At a meta scale, spiders contained the highest number of detected pesticides in perennial crops but lowest diversity in annual crops. This might be explained by how spiders’ functional traits are selected in different crops. Insecticides and fungicides concentrations mostly increased with trophic level, indicating bioaccumulation. Herbicides concentration were highest in plants suggesting (bio)degradation. As bioaccumulation outweighed (bio)degradation, pesticides increased overall with trophic level. Therefore, the distribution of pesticides in agroecosystem food webs was affected simultaneously by several mechanisms and depended upon trophic group, crop type, and, probably, surrounding landscape.

农药威胁着生物多样性，但我们对它们如何渗透到食物网知之甚少。尽管农业生态系统覆盖了地球陆地面积的三分之一，但很少有研究调查农业生态系统食物网中农药的数量、浓度和组成。我们对多年生作物 ( N = 8) 和一年生作物 ( N = 11)中农药在当地（即农场）和元食物网（即当地食物网的区域池）的分布进行了开创性研究，研究了四个营养组——土壤（主要资源）、植物（主要生产者）、啮齿动物（食草动物）和蜘蛛（捕食者）——是否存在多种残留，并将这些发现与农民近年来使用的农药进行比较。我们还采访了农民，以获取有关他们田间农药施用的最准确信息。我们在一年生和多年生作物中检测到了多种农药。农民使用的农药仅占所有检测到的农药的一小部分，这表明农药从周围景观进入当地食物网。一些检测到的农药几年前就已被欧盟禁止，这令人高度警惕。营养群体的流动性和作物类型推动了局部范围内的农药数量，因为流动群体含有更多的农药（可能是因为遇到了更广谱的农药）。在元尺度上，蜘蛛在多年生作物中检测到的农药数量最多，但在一年生作物中多样性最低。这可能是通过蜘蛛的功能性状在不同作物中如何选择来解释的。杀虫剂和杀菌剂的浓度大多随着营养水平的增加而增加，表明存在生物累积性。除草剂在植物中的浓度最高，表明存在（生物）降解。由于生物累积超过（生物）降解，农药总体上随着营养水平的增加而增加。因此，农药在农业生态系统食物网中的分布同时受到多种机制的影响，并取决于营养组、作物类型，可能还取决于周围的景观。