Methoden zur Untersuchung der Populationsdynamik in Obstanlagen

Summary

Research on the dynamics of insect- and spidermite populations in orchards should reveal the effects of the application of plant protecting materials on the total fauna of the orchard. In addition to the research methods hitherto used a simple and time saving method is described, which makes it possible to evaluate the pesticides by collecting random samples of the fauna before and after the treatment. The samples are collected by holding a funnel under the branch and tapping the branch or, after the treatment, with funnels hung under the tree; the best is a combination of both.

In investigations on apple trees during the last years more than 800 species of insects and spiders were caught by using the described “tapping-funnel”. Some samples of groups of insects and spiders, rich in species, however, have not yet been identified. It would be worth while to attempt to calculate the number of Arthropods living in a certain unit of space- f.e. in a cubic meter- of the crown of the apple tree and also the number in the same unit killed by the treatment. If this would be possible the results of experiments carried out under different conditions in different regions would be comparable.