Attack Density and Distribution of Dendroctonus micans (Kugelann) in Standing and Felled Oriental Spruce Trees

Abstract

The aim of this study is to investigate attack density and distribution of Dendroctonus micans (Kugelann) (Coleoptera: Curculionidae) in standing and felled oriental spruce, Picea orientalis (L.) Link., trees. For this purpose, a total of 179 standing and 38 felled trees were evaluated. D. micans attacks largely concentrated in the initial several meters of the boles and particularly in the initial 1 m part of both tree groups. 62.53% and 67.22% of EHs in the initial 2 m of boles of standing and felled trees, respectively were counted in the initial 1 meter. In felled trees, the ratios of entrance holes per meter up to the initial 9 m of boles were similar to each other (%7.02-9.24), other than the significant difference in the initial 1 meter (18.96%). Above nine meters, the ratio of entrance holes per meter of boles varied in the range of 0.54% to 3.64%. In the case of standing trees, unsuccessful entrances comprised 23.40% of the total entrances. In the case of felled trees, approximately one in every four entrance holes in the bole section up to the initial 8 m was unsuccessful, as similar to standing trees, whereas one in every three EHs in upper sections was unsuccessful.