Environmental Entomology (1986) 15, 1090-1095
Jeffrey J. Witcosky, Timothy D. Schowalter and Everett M. Hansen (1986)
Hylastes nigrinus (Coleoptera: Scolytidae), Pissodes fasciatus, and Steremnius carinatus (Coleoptera: Curculionidae) as vectors of black-stain root disease of Douglas-fir
Environmental Entomology 15 (5), 1090-1095
Abstract: This study demonstrates that Hylastes nigrinus (Mannerheim), Pissodes fasciatus LeConte, and Steremnius carinatus (Boheman) are vectors of Verticicladiella wageneri Kendrick, the causal agent of black-stain root disease of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco. These insects, known associates of diseased hosts, wound and create suitable infection courts in susceptible hosts, carry inoculum in the field, and transmit the pathogen to hosts under laboratory conditions. Root systems of 12-year-old Douglas-fir, cut during precommercial thinning, were infested by these insects and were susceptible to V. wageneri infection for at least 7 months, confirming that V. wageneri may be introduced to thinned stands via these hosts. Male and female H. nigrinus created wounds suitable as infection courts on roots and root collars of crop trees for 1-2 years after precommercial thinning and may, therefore, introduce V. wageneri to thinned stands via these hosts. Insectmediated transmission of V. wageneri to Douglas-fir by H. nigrinus in the field is documented.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Timothy D. Schowalter, Everett M. Hansen
Research topic(s) for pests/diseases/weeds:
transmission/dispersal of plant diseases
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Leptographium wageneri | Douglas fir (Pseudotsuga menziesii) | U.S.A. (NW) | ||
| Pissodes fasciatus | Douglas fir (Pseudotsuga menziesii) | U.S.A. (NW) | ||
| Hylastes nigrinus | Douglas fir (Pseudotsuga menziesii) | U.S.A. (NW) | ||
| Steremnius carinatus | Douglas fir (Pseudotsuga menziesii) | U.S.A. (NW) |
