Windthrown Scots pines as brood material for Tomicus piniperda and T. minor.

In the 1980 and 1981, windthrown and felled Scots pine ( L.) were examined at 8 localities in Sweden. The number and length of egg galleries as well as the number of exit holes of (L.) and (Hart.) were recorded on sample sections (30 m in length) distributed at 3 m intervals on the 37 fallen pine stems, which were successfully colonized by the beetles. In addition, 78 uprooted pines were surveyed in 6 localities. Most trees were attacked by , but only a few by Successful colonization often resulted in the production of several thousand beetles per tree, the maximum being approximately 1,800. The attack density of seldom exceeded 200 egg galleries/m bark area, and the brood production usually remained below 1,000 beetles/m. Much higher figures were obtained or In the rate of reproduction (i.e. the number of exit holes /egg gallery) decreased rapidly with increasing attack density, whereas seemed to be less sensitive to intraspecific competition.Pinus sylvestrisTomicus piniperdaT. minorT. piniperdaT. minor.T. piniperda33T. minor.T. piniperda,T. minor