The present invention relates to a device in the form of a container made of a polymer material, which container has one or more sealed chambers, each of which comprise a liquid pheromone comprising 2-ethyl-1,6-dioxaspiro[4,4]nonane, methyl 2,4-decadiene-carboxylate and at least one alcohol selected among 2-methylbut-3-en-2-ol and 2-methylbut-3-yn-2-ol, where at least 50% of the area of the walls forming the chambers have a wall thickness in the range of from 0.1 to 1 mm and the polymer material which forms the chamber is at least in those areas an uncoated vinyl acetate/ethylene copolymer with a vinyl acetate content in the range of from 10 to 17% by weight. The invention also relates to a method of combating and for monitoring the swarming behavior of the species Pityogenes chalcographus, generally also referred to as spruce wood engraver or six-dentated bark beetle.