Planted in many places in human space wonderful trees of horse chestnut (Aesculus hippocastanum) are in danger in Poland because of attack of tiny butterfly horse-chestnut leaf miner (Cameraria ohridella). It came from southern Europe and found new habitats in Central and Western Europe. The method of control to protect against leaf necrosis was injection of insecticides to tree trunk but this application of this method led in many places to trunk necrosis and sometimes died-out of tree was observed,
To avoid such situations in Poland this insecticide was not registered and it happened because of campaign made by environmentalists and among them was Professor Tadeusz Baranowski from Poznań.
To control this pest in a sustainable way in 2006 first experiments were perfomed with artificial mycorrhization using one of our inocula prepared only for trees. To produce such inoculum we had to find chestnut trees which live with symbiosis with mycorrhizas and do not suffer from horse-chestnut leaf miner. We found such trees and mycorrhizal isolates were used to prepare inoculum which was applied in first experiments.