Supporting non-target arthropods in agroecosystems: Modelling effects of insecticides and landscape structure on carabids in agricultural landscapes

Intensification of agricultural practices is one the most important drivers dramatic decline arthropod species. We do not know, however, relative contribution to different anthropogenic stressors that are part this process. used high-resolution dynamic landscape models and advanced spatially-explicit population modelling estimate importance insecticide use structure for dynamics a widespread carabid beetle Bembidion lampros. The effects in-crop mitigation measures through application insecticides with reduced lethality, off-crop by increasing abundance grassy field margins, were evaluated along gradient heterogeneity. Reducing insecticide-driven lethality (from 90 10%) had larger positive impacts on density occupancy than margins in landscape. depended their width overall landscape, but only 4 m wide, applied at least 40% fields, resulted an increase comparable scenario smallest reduction we considered. Our findings suggest rather as supporting stand-alone measure, they generally improved lethality. Therefore, adding sufficiently broad off-field habitats should help maintain viable populations landscapes even moderate insecticides. In general, less persistent environment, found. also showed effectiveness strongly depends farmland Thus, achieve same management or target might require strategies.