Long-term insect censuses capture progressive loss of ecosystem functioning in East Asia

Abstract

Insects provide critical ecosystem services such as biological pest control, in which natural enemies (NE) regulate the populations of crop-feeding herbivores (H). While H-NE dynamics are routinely studied at small spatiotemporal scales, multiyear assessments over entire agrolandscapes are rare. Here, we draw on 18-year radar and searchlight trapping datasets (2003–2020) from eastern Asia to (i) assess temporal population trends of 98 airborne insect species and (ii) characterize the associated H-NE interplay. Although NE consistently constrain interseasonal H population growth, their summer abundance declined by 19.3% over time and prominent agricultural pests abandoned their equilibrium state. Within food webs composed of 124 bitrophic couplets, NE abundance annually fell by 0.7% and network connectance dropped markedly. Our research unveils how a progressive decline in insect numbers debilitates H trophic regulation and ecosystem stability at a macroscale, carrying implications for food security and (agro)ecological resilience during times of global environmental change.

Rising minimum temperatures contribute to 50 years of occupancy decline among cold‐adapted Arctic and boreal butterflies in North America

“…Multiple lines of scientific evidence point to the potential for an alarming recent decline in insect biodiversity across the planet (Cardoso et al., 2020; Wagner, Grames, et al., 2021; Wagner, Salcido, et al., 2021). Major changes in the abundance and composition of insect populations increase the risk of losing vital insect‐mediated ecosystem services, including their role as a food base, and in pollination, decomposition, and pest control (Kremen et al., 2007; Zhou et al., 2023). Consequently, insect declines may even spell the potential for the collapse of some ecological networks (Dunne et al., 2002; Grames et al., 2023; Memmott et al., 2004).…”

“…Major changes in the abundance and composition of insect populations increase the risk of losing vital insect-mediated ecosystem services, including their role as a food base, and in pollination, decomposition, and pest control (Kremen et al, 2007;Zhou et al, 2023). Consequently, insect declines may even spell the potential for the collapse of some ecological networks (Dunne et al, 2002;Grames et al, 2023;Memmott et al, 2004).…”

From Water to Water: Insight into the Translocation of Pesticides from Plant Rhizosphere Solution to Leaf Guttation and the Associated Ecological Risks

“…In the last two decades, increasing evidence indicates a significant decline in populations of beneficial insects, such as wasps, bees, and lacewings, raising global concerns about the loss of biodiversity, agricultural production, and food security (e.g., pollination and biological control). − While beneficial insect population declines are suggested to be caused by numerous environmental stressors such as loss of natural habitats and climate change, continuous pesticide use is clearly an important driver of these declines. − …”

Breakdown in seasonal dynamics of subtropical ant communities with land-cover change

“…Insects comprise 95% of described terrestrial animal species on Earth and are key drivers of a multitude of ecosystem functions and services, including pollination, food provisioning, pest control, water filtration, carbon sequestration and decomposition [1]. Mounting concern about global insect declines due to human-induced environmental change presents a serious threat to a sustainable future for humanity [2][3][4]. However, less is known about how anthropogenic stressors change intra-annual patterns of variability and seasonality, which are also crucial for ecosystem functioning and services.…”