STUDY ON THE INFESTATION BY CAMERARIA OHRIDELLA ON AESCULUS HIPPOCASTANUM FOLIAGE FROM TIMI OARA, ROMANIA

Cameraria ohridella is the most important pest on the horse chestnut trees (Aesculus hippocastanum) in Timi oara. Aesthetic damage is severe. In all cases regular and high infestation with the moth was recorded. Infestation levels increased after the fruiting phenophase. The dangerous and frequent fungus, disturbing horse chestnut leaves – Guignardia aesculi – was recorded. Aesculus x carnea sometimes shows infestation, if it is planted near heavily infested horse chestnut trees. We determined the histoanatomical and ecophysiological parameters: leaf thickness (LT), leaf thickness lost (LTL), leaf relative water content (LRWC), leaf ash content (LAC), succulence(S) and specific leaf aria (SLA). The development of galleries by Cameraria ochridella is achieved on leaf maturity, when their thickness exceeds 135μm. It is assumed that larvae did not show a preference for leaves of an urban area or green area. Our data indicate that stress resulting in simultaneous attacks carried out by Cameraria ochridella and Guignardia aesculi on Aesculus hippocastanum leaf is combined with stress given by intense traffic. In the second and third decade of July increased level of infestation, more severe in urban areas with heavy traffic.