In the scope of preventive strategy the method of Theysohn's control - catch traps used for controlling and reduction of Ips typographus population was used in the lowlands spruce forest GGE Vrbovec, Kočevska in 2004. For this purpose there were 107 traps on 54 locations, monitoring the number of trappedbark beetles during the entire season (from April to September). On thebasis of the catch we tried to establish the distribution of the populationand compared it with the damages on standing spruce trees caused by the Ips typographus. The analysis of the damages on the standing spruce trees caused by the insect in forest management area of Kočevje (GGO Kočevje) and forest management unit Vrbovec (GGE Vrbovec) is also included in this thesis. By observing focal points we tried to establish spatial patterns of the spreadof Ips typographus. We found out that the catch decrease corresponds with the catch duration. The largest catch of Ips typographus was in the 3rd decade of April and in the 1st decade of May. The maxima of the catch represent swarming of generations. In 2004 two generations developed. Sister generations were not observed on the catch basis. For the short - termed prognosis we tried to establish correlations between the trap - catches by individual focal points in the spring time and the amount of infected spruce trees cut. The spring catch (from April to June) presents 82 % of whole catch (from April to September). The catch cumulations in traps by individual focal points in the spring time is in correlation with the amount of trees cut for sanitary purpose in area of traps. From this correlation we also established the regression between the average catch per trap (number of subjects per trap) during spring time and the relative amount of spruce tree cut in the focal points. The acquired results are not comparable with the similar research projects of other authors, because of a one - year observation of thecatch and the amount of trees cut for sanitary purpose and also the methodology of work, in our case used with an operational aim for the reduction of species (Ips typographus) population.