Root-Colonizing Insects Recovered from Douglas-Fir in Various Stages of Decline Due to Black-Stain Root Disease
- 1 January 1985
- journal article
- research article
- Published by Scientific Societies in Phytopathology®
- Vol. 75 (4) , 399-402
- https://doi.org/10.1094/phyto-75-399
Abstract
Douglas-fir (P. menziesii) trees infected with Verticicladiella wageneri was assigned to 1 of 5 symptom classes by crown color and terminal growth characteristics at 3 widely separated sites in the Coast Range of Oregon [USA]. Root systems of trees in each symptom class were excavated, and the insects beneath the bark were collected. Two weevils, Steremnius carinatus and Pissodes fasciatus, and the root bark beetle Hylastes nigrinus were commonly associated with diseased trees. Insects sequentially colonized roots of diseased trees as each root succumbed to infection; the colonization period generally lasted from 2-4 yr. The occurrence of these root-colonizing insects throughout the decline of the host suggests that S. carinatus, P. fasciatus and H. nigrinus may act as vectors of V. wageneri in this ecosystem.This publication has 0 references indexed in Scilit: