Tree Diversity Alters Arthropod Trophic Groups and the Predation of Artificial Plasticine Larvae in Mango Agroecosystems

ABSTRACT Understanding the factors governing biodiversity in agroecosystems is essential for assessing and enhancing ecosystem services. Increased tree diversity in agroforestry systems can promote arthropod diversity, strengthen trophic interactions and improve natural pest control. However, the effects of tree diversity and abundance on the stability of arthropod food webs remain insufficiently understood. We investigated the role of tree diversity and abundance in mango orchards on the stability of arthropod food webs and their potential for pest control. We studied 20 mango orchards across two departments in northern Benin, known for their high mango production. Arthropods were sampled using pitfall traps half‐filled with soapy water buried flush with the ground within a clearly defined 20 m × 20 m plot within each orchard. In addition, we censused trees associated with the orchards in these same plots. Predation rates were assessed using the sentinel prey method with artificial caterpillars made of modelling clay. We found that arthropods were mainly composed of Hymenoptera, with 70% of ants, and five other arthropod orders, namely Orthoptera, Araneae, Coleoptera, Diptera and Dictyoptera. Tree diversity and abundance associated with mango orchards and arthropod diversity had significant effects on the abundance of all arthropod functional groups (predators, omnivore‐predators, pollinators and herbivores). Tree diversity and abundance increased the abundances of arthropod predators and pollinators. Pollinator abundance was positively associated with predator abundance, suggesting that both guilds are responding to the same cues. In contrast, omnivore‐predator abundance was negatively associated with herbivore abundance, which may indicate predator–prey dynamics. Our study highlights the importance of plant diversity and agricultural practices for the agroecological control of pests.