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.
science advances, if="14.957
https://pubmed.ncbi.nlm.nih.gov/36735783/
