Kolenkina M. Spread of foci of pine sawflies in the East Ukraine and their influence on forest condition

Object - dynamics of defoliation, sanitary condition and growth of pine stands in the foci of pine sawflies; Aim - revealing the regularities of spread of foci of pine sawflies in the Eastern Ukraine and their influence on condition of pine stands; methods - silvicultural, taxation, dendrochronological, entomological, statistical; novelty - increase of severity, frequency, duration of outbreaks of pine sawflies in 2001-2010 was proved; the threat of their foci forming in the stands of Luhansk region was predicted; reasonability of defoliation prediction by larvae nests' density was proved; relations between crown damage by pine sawflies and sanitary condition of the stands are evaluated; extreme level of crown damage was defined, which brings to tree mortality; dynamics of radial increment in the foci of pine sawflies were evaluated; results - forest plots with the highest threat of outbreaks of pine sawflies were determined using numerical score; an algorhythm was developed for prediction of stand damage by pine sawflies, the dates of survey of population density and treatment by insecticides; probability of pine trees' mortality in the foci of pine sawflies was evaluated; sphere of application - forestry.