Statystyczna metoda oceny zagęszczenia populacji rytownika pospolitego Pityogenes chalcographus L. na wiatrowałach świerka Picea abies (L.) Karst.

Pityogenes chalcographus L. (Col., Curculionidae, Scolytinae) is a pest of Norway spruce Picea abies (L.) Karst. characterized by large fluctuations in population size. Despite many publications devoted to P. chalcographus, no accurate method of estimating the population density of this species has been developed. The aim of this study was to develop a statistical method of estimating the total density of P. chalcographus colonising stems and branches of P. abies wind−fallen trees that enables calculation of estimation errors and does not require debarking of whole stems and branches. Linear functions were applied to calculate the total infestation density of stems and branches of P. abies windfalls. The mean relative errors of estimation for stems and branches were smaller than 35% and 45%, respectively.