VISITATION FREQUENCIES OF SOME INSECT SPECIES ON CERATOCYSTIS WAGENERI INFECTED AND APPARENTLY HEALTHY PONDEROSA PINES

Abstract

AbstractTo test the hypothesis that bark beetles and some associated insect species are attracted to ponderosa pines infected by Ceratocystis wageneri, insect visitations on 11 severely diseased, 9 moderately diseased, and 10 apparently healthy trees were monitored from 1 August to 15 October 1972. Larger numbers of Dendroctonus brevicomis, D. ponderosae, Temnochila chlorodia, and buprestids were captured on diseased trees uninfested by bark beetles than on apparently healthy ones, thus possibly indicating attraction to diseased trees. There was strong evidence that D. valens and Spondylis upiformis were attracted more frequently to wounds on diseased than on healthy trees. Arrival patterns of beetles were recorded for trees that became infested during the study. Predators became abundant on traps as bark beetle catches increased.