THE STRUCTURE OF LEAF DAMAGE BY TREE PESTS IN ROADSIDE PROTECTIVE SHELTERBELTS
The condition of protective forest plantings along highways is an understudied issue. The shelterbelts were planted more than 50 years ago and there is practically no maintenance. The research goal was a quantitative accounting and the analysis of the structure of leaf damage types in the trees of roadside shelterbelts. The research target was a segment of the highway Dnepropetrovsk - Donetsk (32 km). This part of the highway is characterized by heavy traffic and is situated in a zone of insufficient moisture supply. It has been found that the proportion of different types of leaf damage of the studied tree species differs. Most damage types are marginal and rough nibbling and holes in leaves. Leaf skeletonization was found only on Quercus robur, Ulmus laevis and Ulmus glabra. Marginal leaf damage was found on significant number of species particularly on Acer platanoides, Tilia cordata, Betula pendula, Quercus robur and Populus nigra. Galls were found on the leaves of Quercus robur, Salix alba, Juglans regia and Tilia cordata. The plants of Aesculus hippocastanum were mostly weakened; all plants were affected by the horse chestnut leaf miner. There were many leaves with marginal and perforated damages on Acer platanoides, Armeniaca vulgaris and Juglans regia. Marginal and rough nibbling is more common on Quercus robur and Populus nigra. All damage types were found on Tilia cordata, Quercus robur and Ulmus laevis. The leaves of Aser negundo, Robinia pseudoacacia and Gleditsia triacanthos are slightly damaged by phytophages. These resistant species form the basis of the structure of the studied roadside protective shelterbelts.