A method for the protection of spruce stands against Ips typographus by the use of barriers of pheromone traps in north-eastern Slovakia

A method and layout of various systems of barriers of pheromone traps is described. The rationale of the method is based on the stress of spruce and the chemical communication of Ips typographus. Various systems of pheromone trap barriers were used according to the required level of protection. The method was used in two areas affected by air pollution and bark beetle outbreak. The first area was in an unnatural spruce monoculture region while the second was in a National Park. The described method led to a significant reduction of bark beetle attacks on trees along forest edges and subsequently to the stopping of movement of the zone of attacked trees due to bark beetle damage. In the case of forest stands with no reduced canopy closure, the reduction of attacks led to a dramatic decline of bark beetle outbreak. On the other hand, this method was not able to reduce the level of bark beetle attack in the interior of forest stands with a decreased level of canopy closure. This method as part of differentiated pest management measures in one forest district, was successful without any other protection measures in the condition of natural reserves in a spruce vegetation zone.