© Marcel Burkhardt
Grüebler, M.U., Morand, M. & B. Naef-Daenzer (2008)
Agricult. Ecosyst. & Environment 123: 75–80
This paper presents a model to predict the daily spatio-temporal variation in the abundance of airborne insects in agricultural landscapes on the basis of publicly available environmental data. Data on the abundance of insects flying near ground level were collected by a robust and effective point-count method. The validation of the model using extra data revealed a high correspondence between predicted and observed insect density. The final model showed that the abundance of airborne insects depended largely on the daily weather conditions. Agricultural habitats differed in the abundance of airborne insects, with peak insect numbers found along hedgerows and trees. This accumulation pattern was most pronounced at low temperatures and in windy conditions. Efforts to enhance insect abundance in agricultural landscapes therefore need to increase the number of structural elements such as hedgerows, single trees and orchards. This study highlights how weather conditions and agricultural land-use affect aerial food webs in agri-environments, including the dynamics of food patches for all kinds of aerial foragers.
Keywords: Above-ground arthropods; Insect abundance estimation; Aerial food supply; Landscape heterogeneity