Repression of Ips typographus Infestations in Stored Logs by Semiochemicals

Logs of fresh‐felled Norway spruce were stored close to the south‐facing edges of clear‐cuts from the previous winter and treated with controlled release formulation of: 1. The pheromone components verbenone and ipsenol, which act as antiaggregative pheromone in Ips typographus. 2. Turpentine, a by‐product derived from pulp mills. The experiments were conducted in 3 locations in South‐Norway during a 3‐year period. All experiments show that treatments with a combination of verbenone and ipsenol released from laminated structure dispensers significantly reduced the attack density of I. typographus, whereas turpentine treatment had no effect on the rate of beetle infestations.