Observer bias and the detection of low-density infestations: a case study with the hemlock woolly adelgid
| Authors: | Matthew C. Fitzpatrick, Evan L. Preisser, Aaron M. Ellison, Joseph S. Elkinton |
| Year: | 2009 |
| Type: | Other |
| Station: | Northern Research Station |
| Source: | In: McManus, Katherine A; Gottschalk, Kurt W., eds. Proceedings. 20th U.S. Department of Agriculture interagency research forum on invasive species 2009; 2009 January 13-16; Annapolis, MD. Gen. Tech. Rep. NRS-P-51. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 21-23. |
Abstract
Monitoring programs, often comprised of volunteers, increasingly are used to document the spread of forest pests in the hope of detecting and eradicating low-density infestations before they become established. However, interobserver variation in the detection and correct identification of low-density populations of forest pests remains largely unexplored. In this study, we compared the abilities of novice observers and experienced individuals to detect low-density populations of the hemlock woolly adelgid (HWA) and we explore how interobserver variation can bias estimates of the proportion of site infested derived from models.
Parent Publication
- Proceedings. 20th U.S. Department of Agriculture interagency research forum on invasive species 2009