Arthropod food webs predicted from body length ratios are improved by incorporating prey defensive properties

This dataset was used to run for Van de Walle et al. (2023). Arthropod food webs predicted from body length ratios are improved by incorporating prey defensive properties. Journal of Animal Ecology, 92(4), 913-924. https://doi.org/10.1111/1365-2656.13905 "Arthropod_feeding_trials.csv" contains the results of the experimental feeding trials. Each row contains information on species taxonomy, body size and hunting strategy within a single trial. Abstract Trophic interactions are often deduced from body size differences between predators and potential prey, assuming predators prefer prey smaller than themselves because larger prey are more difficult to subdue. This hypothesis has mainly been confirmed in aquatic ecosystems, but rarely in terrestrial ecosystems, especially in arthropods. Our goal was to validate whether body size ratios can accurately predict trophic interactions in a terrestrial, plant-associated arthropod community. Additionally, we tested whether predator hunting strategy and prey taxonomy could explain possible deviations from this general rule. We collected arthropods from marram grass in coastal dunes and conducted pairwise feeding trials to explicitly test whether two individuals, of the same or different species, would predate each other. From the trial results, we constructed one of the most complete, empirically derived food webs for terrestrial arthropods associated with a single plant species. We contrasted this empirical food web with a theoretical web based on body size ratios, literature and expert knowledge. In our feeding trials, predator-prey interactions were indeed largely size-based. Moreover, the theoretical food web based on body size, activity period, microhabitat and expert knowledge converged quite well with the food web based on experimental feeding trials for both predator and prey species. However, predator hunting strategy, but mainly prey taxonomy improved predictions of predation events. Well-defended taxa, such as hard-bodied beetles, were less frequently consumed than expected based on their body size. Body size ratios predict trophic interactions among plant-associated arthropods fairly well. However, traits such as hunting strategy and anti-predator defences can explain why certain trophic interactions do not adhere to size-based rules. Feeding trials can generate insights into multiple traits underlying real-life trophic interactions among arthropods. Such insights are much needed as the dramatic global decline in arthropod species richness and abundance is knocking out many trophic interactions on which services such as pest control and nutrient cycling depend.本数据集用于Van de Walle等人（2023）的研究：《通过纳入猎物防御特性优化基于体长比预测的节肢动物食物网》，发表于《动物生态学杂志》（Journal of Animal Ecology）92卷第4期，页码913-924，DOI：10.1111/1365-2656.13905。 文件"Arthropod_feeding_trials.csv"包含实验摄食试验的结果，每一行对应单次试验中的物种分类学信息、个体体型以及捕食者的捕猎策略。 ## 摘要 营养级相互作用通常基于捕食者与潜在猎物间的体型差异推导得出，其默认前提为捕食者更偏好体型小于自身的猎物，因为制服更大的猎物难度更高。该假说主要在水生生态系统中得到验证，而在陆地生态系统中鲜有验证，针对节肢动物类群的相关研究更是匮乏。本研究旨在验证：体长比能否准确预测陆地生境中与植物关联的节肢动物群落内的营养级相互作用。此外，我们还检验了捕食者捕猎策略与猎物分类学特征是否能够解释该通用规律可能存在的偏离情况。 我们从海岸沙丘的滨麦草（marram grass）中采集节肢动物，并开展成对摄食试验，以明确检验同种或不同种的两个个体是否会发生捕食行为。基于试验结果，我们构建了目前最为完整的、基于实证的单植物物种关联陆地节肢动物食物网之一。我们将该实证食物网与基于体长比、文献资料及专家知识构建的理论食物网进行了对比。 在摄食试验中，捕食者-猎物间的相互作用确实主要基于体型关系。此外，基于体型、活动节律、微生境及专家知识构建的理论食物网，与基于实验摄食试验得到的捕食者与猎物物种食物网吻合度较高。不过，捕食者捕猎策略，尤其是猎物的分类学特征，能够提升捕食事件的预测精度。具备良好防御能力的类群（如硬鞘甲虫），其被取食的频率相较于基于体型的预期值更低。 体长比能够较好地预测植物关联节肢动物间的营养级相互作用。然而，诸如捕猎策略与反捕食防御等功能性状，可以解释为何部分营养级相互作用并不遵循基于体型的规律。摄食试验能够帮助我们深入理解节肢动物间真实营养级相互作用背后的多重性状机制。鉴于全球节肢动物物种丰富度与种群数量正发生急剧下降，诸多依赖于害虫防控、养分循环等生态系统服务的营养级相互作用正随之消失，这类研究洞察显得尤为必要。