The purpose of this exercise is to determine the population dynamics of eight-toothed spruce bark beetle (Ips typographus (L.)) and six-toothed spruce bark beetle (Pityogenes chalcographus (L.)) in the Vodice district, Ljubljana forest management unit. Catches were monitored at nine locations with three control-hunting traps of type Theysohn at each location, which were equipped with standard population pheromone baits Pheroprax and Chalcoprax. The purpose of this exercise is also to determine the impact of pheromone baits on treated spruce bark beetles and to determine the dependence of the catch according to ecological factors. Analysis has shown that the number of individuals varies according to the type of the pheromone bait, altitude, position, air temperature, rainfall, and relative air humidity. Samples have been taken from the end of April 2008 until mid October 2008. Additional catch of non-target species of arthropods (Arthropoda) has also been regularly observed, for which the order has been determined. Additionally the families have been determined for the representatives of the order beetles (Coleoptera), class insects (Insecta).