Bondareva L. Biological substantiation of the apple protection the European apple sawfly (Hoplocampa testudinea Klug.) in the Northern Forest-steppe of Ukraine

Object of research - European apple sawfly. The purpose of the investigations: is a substantiation and improvement of the system of intense orchards protection from the European apple sawfly on the basis of prognosing its propagation and harmfulness limit on various apple cultivars. Methods: field, laboratory, statistical. The scientific novelty: For the first time under the conditions of the Ukraine's Northern Forest-steppe the author has established that the European apple sawfly harmfulness shows itself when its larva's affect 32 and more percent of ovary. The phytophagne harmfulness limit has been determined depending on a cultivar's yield and thickness of trees planting. Three varieties have been detected which are relatively resistant to the apple sawfly. In thick orchards with the planting plans 4 ґ 2; 3 ґ 1, 2,5 ґ 1 м the phytophagne harmfulness appeared to increase by 2 or 3 as compared to the orchards with the traditional plans. The mathematical models of the season prognosing of the pest amount have been elaborated which are based on the indexes of the soil temperature, precipitations, air relative humidity and hydrothermal coefficient. The author has proved that the soil tillage with the rotary tiller FA-076 during the period of the European apple sawfly mass pupation does not influence considerably its amount. The efficiency of the modern pesticides (73.8-93.1%) against the phytophagne has been determined. The purposefulness of but one treatment using them after flowering has been substantiated. The improved system of the apple protection against the pest has been proposed.