Exploring multitrophic interactions in oilseed rape fields reveals the prevailing role of Carabidae

In cropped fields, birds are often at the highest position in the food chain, feeding on pest arthropods and their intermediate predators in a process known as intraguild predation. The net effects of bird predation on phytophagous insect populations (feeding on plants) are difficult to predict without comprehensively describing prey-predator communities and their complex interplay. We sampled bird and arthropod communities in 30 oilseed rape fields in the spring of 2019 and 2020 in France. To assess the top-down control of arthropods by birds, we used a vertebrate exclusion experiment. Using a taxonomic and functional trait-based approach, we determined the direct and indirect influences of birds on arthropod predators and phytophagous insect populations in arable crops. We observed a negative relationship between the abundance of Carabidae and phytophagous insects but not with the other predator group suggesting the key role of Carabidae on phytophagous insects in agroecosystem. We fo...

在农田中，鸟类通常处于食物链的最高营养级，以害虫节肢动物及其中间捕食者为食，这一过程被称为集团内捕食（intraguild predation）。若未全面阐明猎物-捕食者群落及其复杂互作关系，便难以预测鸟类捕食对植食性昆虫（以植物为食）种群的净效应。我们于2019年与2020年春季在法国的30块油菜田中开展了鸟类与节肢动物群落采样工作。为评估鸟类对节肢动物的下行调控作用，我们采用了脊椎动物排除实验。通过基于分类学与功能性状的研究方法，我们明确了农田作物中鸟类对节肢动物捕食者以及植食性昆虫种群的直接与间接影响。我们观测到步甲科（Carabidae）的丰度与植食性昆虫种群呈负相关关系，而其他捕食类群则无此关联，这表明步甲科在农业生态系统中对植食性昆虫发挥着关键调控作用。我们发现