Both the homogenisation of agricultural landscapes and the associated loss of suitable habitats and resources as well as the intensified use of synthetic chemical pesticides are considered to be key drivers of the long-term decline in the abundance and diversity of insects (Sánchez-Bayo and Wyckhuys 2019).

Reducing the local pesticide load through NocsPS cultivation systems is therefore a promising approach to promoting insect biodiversity and associated ecosystem services, e.g. natural pest control (Zimmermann et al. 2021).

The aim of the research project is to understand the effects of cropping systems, the associated pesticide load and the structuring of agricultural landscapes on the occurrence and distribution of insects and their ecosystem services. The work includes studies on plant biodiversity, vegetation structure and the abundance of beneficial insects at different spatial scales (plot, field, field margins, landscape).

The following hypotheses will be tested in detail:

• The abundance of beneficial insects can be explained by spatiotemporal variation in the availability of suitable habitats and resources both in the field (e.g. field wild herbs) and in field margins (e.g. flowering strips) and at the landscape scale.
• UAV-based and remote sensing data on land use and vegetation structure allow conclusions to be drawn about the habitat quality for beneficial insects.
• Abundance of beneficial insects and the potential for natural pest control are higher in agricultural landscapes with high land-use diversity and low pesticide contamination.
• Lower pesticide use at the landscape scale promotes insect biodiversity and yield-relevant ecosystem services (in addition to local effects of pesticide avoidance at the impact scale).

The investigations are carried out in close coordination and cooperation with the other ecological joint projects (VP8, 9, 11) in a joint study design of the Biodiversity Cluster in 20 study landscapes of 1 km × 1 km each with contrasting csPPP contamination. In these landscapes, vegetation surveys and sampling of arthropod occurrence within the selected winter wheat fields and in arable field habitats will be carried out in the 2026 field season. The sampling of arthropods on vegetation and soil surface will be carried out according to the protocol established in the previous project phase using an insect vacuum cleaner, and the frozen samples will be analysed with regard to abundance, biomass and diversity of the target groups (aphids, cereal bugs and their antagonists) as well as general biodiversity.

The ecosystem services provided (in particular predation pressure on insect pests) are also directly quantified in the field using rapid ecosystem service assessment methods. In addition, UAV-based multispectral camera systems are used to create high-resolution and area-wide images of various landscape sections in order to quantify the vegetation structure and the availability of resources for beneficial insects (e.g. flower cover).