recent Ips typographus outbreak in Norway--experiences from a control program

During the period 1971-81 there were severe outbreaks of the bark beetle Ips typographus in southern Norway that damaged trees equivalent to 5 million cubic metres of timber. The outbreaks were caused partly by an extensive windblow and partly by drought. Trap trees were used until 1979, when pheromone-baited traps were introducted as part of an extensive control program. The various aspects of this program are outlined and problems of scientific, technological, economical-administrative and informative character are discussed. Possible explanation for the decline of the epidemic after 1980 is presented and the main conditions which must be fulfilled for achieving successful mass trapping of insect pests are listed.