INVESTIGATIONS ON THE EXISTENCE OF BENEFICIAL ORGANISMS ON URBAN TREES IN BERLIN

Investigations in Berlin showed that many beneficial organisms are present on urban trees.
Predatory mites (Seiulus aceri, Kampimodromus aberranc), predatory bugs (Anthocoidae, Miridae), Coccinellidae, Chrysopidae and Syrphidae were found, but their presence is dependent from the local situation.
For example spidermites (Tetranychus urticae, Eotetranychus tiliarum) damages more lime-trees (Tilia spec.) on broad streets than on small streets or in parks.
Predatory mites were present in all areas, but on the trees of broad streets the lowest.
Furthermore the presence of predatory mites is dependent of the climatic conditions of the year, therefore the population is higher in years with lower temperatures and more rain.
In this case they are able to control the spidermites on all tree stands.
The results show that many predators are present in urban areas and that the local architecture influences their population and activity.
Investigations are necessary to understand the living space of main predators to optimize the landscape and the tree care in such a way, that beneficial organisms will find good conditions.

International Symposium on Urban Tree Health

H. Balder, B. Jäckel, B. Pradel

Beneficial organisms, integrated pest control, predatory mites, spidermites, lime-tree

https://doi.org/10.17660/ActaHortic.1999.496.24