How does increased crop diversity lead to higher arthropod biodiversity and enhanced ecosystem services?

Insect biodiversity is declining at an unprecedented rate, for which intensified agriculture and pesticide use are the two main reasons. Also, the loss of insect biodiversity will likely lead to losses in biodiversity of higher trophic levels dependent on insects, such as birds and mammals. This decline is expected to have major effects on crop yield through increased pest pressure. Currently, most agricultural crops are grown in large-scale monocultures. These monocultures have the benefit of being easily managed, but from an ecological perspective these homogenous landscapes only benefit certain insect species. These species tend to become pests on these crops and are mainly controlled with chemical pesticides. An ecological alternative to monocultures would be intercropping practices, in which two or more crops are grown in close association within a field. These systems benefit from an increased biodiversity, which in turn would increase crop health and productivity, and reduce the need for pesticides. Recent technological advances have already made some practices of intercropping on a large-scale possible. The proposed research aims to further optimize intercropping practices for large-scale use. We will unravel how crop diversity can enhance predator and parasitoid abundance, and how this can decrease pest pressure and increase crop productivity. This knowledge is vital to the acceptance of these practices by farmers and policy makers, and for further optimization of intercropping practices. The use of intercropping as the main farming practice will aid ecological resilience and help conserve our biodiversity.