It was organized by the Federal Forest Research Institute in Vienna and the International Society of Arboriculture. The workshop was attended by more than 100 people. The meeting started with presentations describing the pest biology and the situation in Austria and the neigh-bouring countries. Cameraria ohridella was first observed in Macedonia in 1983 and described in 1986. It was accidentally introduced into Austria in 1989 and has since extended its distribution to Italy, Germany, the Czech Republic, Slovakia and Hungary.
Damage is severe, especially in Austria where total defoliation is often observed.
Cameraria ohridella damage attains great public attention, especially in Austria because horse chestnut is a very common ornamental tree, frequently planted in gardens, parks and along roads. The origin of the pest is unknown. It was first suggested that it originates from the Balkans, the area of origin of its main host, Aesculus hippocastanum , but there are several arguments suggesting that it may originate from other regions where native Aesculus spp. The second part of the workshop consisted of presentations on potential control methods. Other control methods included aerial application of Dimilin and closely related substances, cultural practices such as the removal or composting of dead leaves, systemic insecticides by stem injection or infusion, or a less conventional electrotechnic method using cosmic energy.