SPECIES DIVERSITY OF HARMFUL BARK BEETLES IN SPRUCE FORESTS OF ADJARA REGION (GEORGIA)

Several species of Bark beetles (Coleoptera: Scolytinae) are capable of causing significant amounts of tree mortality in conifer forests throughout much of the world and in the South Caucasian Mountain as well. In the paper, is discussed about species diversity of harmful bark beetles, which are damage and cause the decline of the Picea orientalis, in the conifer forest of Shuakhevi and Khulo municipalities of Adjara (Western Georgia), at an altitude of 700-1500 m a.s.l. This is one of the current problems in spruce forests of mentioned region. Field studies were carried out in Shuakhevi municipality at 700-900 m a.s.l. and in Khulo municipality 1200-1500 m a.s.l. The route expedition, planning of the research area, insect identification, bioecology-phenology, using pheromon traps were used for the accepted methods. The statistical processing of the data was carried out mathematically modeling through the IMB-SPSS23 program. As a result of the research, it was revealed that in the coniferous forest of Shuakhevi and Khulo, where represented Picea orientalis , damage to the bark and the drying of the plant are caused by the most important three species of bark beetle: Ips typographus L., Ips sexdentatus Boern. and Dendroctonus micans Kugelann. Also, were found that all three species live together under the bark. The optimal limit of their distribution was established. It should be noted that all three species gives only one generation in a year in spruce forests of Adjara. Compared to spruce forests damages by bark beetles of Khulo municipality, to Shuakhevi municipality is 30% higher. The optimal limit of their distribution is 700-1000 m. a.s.l.