A Comparison of Radiograph Analysis and Bark Dissection in Estimating Numbers of Western Pine Beetle

Abstract

Estimates of the numbers of the western pine beetle, Dendroctonus brevicomis LeConte, in Pinus ponderosa Laws, bark samples were made by radiographs of 25 bark samples and by dissection counts of the bark. High correlations (r = >.9) between the two methods were found for (a) live larvae, (b) live plus dead larvae, (c) live of all stages combined, and (d) live plus dead of all stages combined. The bark dissection method took eight times as long and was 4⅓ times as expensive as the radiographic interpretation method of estimating bark beetle numbers.