Effects of intensive versus no management strategies during an outbreak of the bark beetle Ips typographus (L.) (Col.: Curculionidae, Scolytinae) in the Tatra Mts. in Poland and Slovakia

An intensive bark beetle outbreak occurred in 199319941995199619971998 in the Tatra mountains between Slovakia and Poland. In the Slovak part of the outbreak practices consisted of: no action prior to 1994, intensive pest control management (trap trees, insecticides, salvage cutting) from 1995-1996, active differentiated approach (control measures according to the zonation of attacked stands) combined with intensive use of pheromone traps from 1997-1998. In Poland, the outbreak was mostly located in reserve areas where pest management or other activities were prohibited. Despite the use of intensive pest management measures, tree mortality was not significantly decreased in the Slovak region during the peak outbreak years of 1995 and 1996. Classical forest protection led to an increase in attractiveness of forest edges to bark beetles which could disperse to these areas from locations where no control measures were practiced. Unfavourable weather for bark beetles led to a rapid decrease in tree mortality in both parts of the study area.