Parasitic wasps and flies or specialized predators such as hoverflies, ladybirds or pirate bugs are closely intertwined with the population dynamics of their host and prey species and have therefore a prominent function in food webs. They are important indicators for the ecosystem service "pest control" and also indicate the presence of certain host species. The aim of such trend monitoring is to provide a data basis on long-term population changes of these beneficial insects as a function of land use and other exogenous factors (e.g. climate changes). Methods for monitoring selected target groups will first be established at selected sites and their suitability for long-term trend monitoring will be tested. In addition, parameters are recorded that can be used to assess the fitness status of these species depending on the food resources available in the agricultural landscape using biochemical and physiological methods. The aim is to model the sampled land use systems on the species spectrum, frequency and fitness status of various beneficial insects.
The system for trend monitoring will initially be developed at several locations in southwest Germany. This region is climatically favoured and shows a diverse cultivation of crop plants and a highly structured agricultural landscape. In the model phase, monitoring will take place in refuge habitats (hedges, possibly permanent fallow land) in the agricultural landscape, in permanent grassland and in orchard meadows. Long-term supervision by the Institute of Biological Plant Protection should be possible or extended to other regions in cooperation with other institutions. In addition, the Institute for Plant Protection in Fruit Crops and Viticulture will also establish a system for trend monitoring of parasitic wasps, but also wild bees and grave wasps relevant to nature conservation in differently managed vineyards.
Dr. Annette Herz