Dendroctonus pseudotsugae (Coleoptera: Curculionidae: Scolytinae) sequential sampling data

The Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, attacks Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco (Pinaceae), throughout western North America. Periodic outbreaks cause increased mortality of its host. Bark samples were obtained from 326 trees distributed over 21 stands during a 2-year period in the late winter to early spring of 1997 and 1998 in the Colorado Front Range. Data include tree size, brood and gallery counts, as well as length and placement of each gallery. Land managers and forest health specialists often need to determine population trends of this insect. In this study, we developed a fixed-precision sequential sampling plan that resource managers and forest health specialists could use to sample Douglas-fir beetle brood adults and determine their density per unit area.