Advances in ecotoxicological effects of trace metal elements and pesticide pollution on predatory spiders in agroecosystems

Spiders are widely distributed arthropods in agroforestry ecosystems, serving as key biological control agents against field pests. However, trace metal elements (TMEs) and pesticide contamination pose significant threats to ecosystems and organisms, attracting global attention. This review delineates the ecotoxicological mechanisms underlying spider responses to TME and pesticides, focusing on their roles as biological control agents. It summarizes the impacts of TME and pesticides on genetic traits and physiological mechanisms in spiders, including development, reproduction, detoxification, immunity, metabolism, and neurology. Additionally, it explores the potential of spiders as bioindicators. Multi-Omics analyses reveal changes in ecdysteroids, oocyte meiotic pathways, germ cell adhesion, metallothioneins, detoxification enzyme activities, Toll-like receptor signaling, and oxidative phosphorylation under TME stress. Mechanistically, TME and pesticides induce differential gene expression, DNA damage, disrupted metabolic pathways, and oxidative stress. Sublethal pesticide doses alter spider physiology, biochemistry, and behavior by affecting neurotransmitters, DNA integrity, chitin synthase, photoreceptors, and biological clocks. Despite growing interest in spider ecotoxicology, the adverse effects of TME and pesticide exposure on their digestive, respiratory, and immune systems remain poorly understood. Elucidating these mechanisms could enhance spider-mediated biological control, ultimately improving crop yields.