SAMPLING PROCEDURES FOR WITHIN-TREE ATTACKING ADULT POPULATIONS OF THE SOUTHERN PINE BEETLE, <i>DENDROCTONUS FRONTALIS</i> (COLEOPTERA: SCOLYTIDAE)

Abstract

Abstract Quantitative sampling schemes for estimating within-tree populations of attacking Dendroctonus frontalis Zimmerman were investigated. Accuracy and precision of five small sample procedures were affected by the number and location of the sample heights, the number of sample disks per sample height, and the techniques used for calculating infested surface area and average insect density. Best small sample estimates were obtained from samples near the middle of the infested bole. Unbiased, minimum variance combinatorials were derived. High precision estimates were obtained only by sampling the infested bole at frequent intervals.