| Title: | Derivation of Pheromone-Based Larval Thresholds in Spruce Budworm Accounting for Distance to Defoliated Forest Stands |
| Author(s): | Rhainds M; DeMerchant I; Therrien P; |
| Address: | "Natural Resources Canada, Canadian Forest Service - Atlantic Forestry Centre, Fredericton, New Brunswick, Canada. Ministere des Forets, de la Faune, et des Parcs, Direction de la Protection des Forets, Service de la Gestion des Ravageurs Forestiers, Quebec, Canada" |
| ISSN/ISBN: | 1938-291X (Electronic) 0022-0493 (Linking) |
| Abstract: | "Spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is the most severe defoliator of Pinaceae in Nearctic boreal forests. Three tools widely used to guide large-scale management decisions (year-to-year defoliation maps; density of overwintering second instars [L2]; number of males at pheromone traps) were integrated to derive pheromone-based thresholds corresponding to specific intergenerational transitions in larval densities (L2i --> L2i+1), taking into account the novel finding that threshold estimates decline with distance to defoliated forest stands (DIST). Estimates of thresholds were highly variable between years, both numerically and in terms of interactive effects of L2i and DIST, which limit their heuristic value. In the context of early intervention strategy (L2i+1 > 6.5 individuals per branch), however, thresholds fluctuated within relatively narrow intervals across wide ranges of L2i and DIST, and values of 40-200 males per trap may thus be used as general guideline" |
| Keywords: | Animals Forests Larva *Moths *Pheromones boreal forest disturbance eruptive population dynamics large-scale forest pest management program monitoring of forest defoliator sink-hole population dynamics; |
| Notes: | "MedlineRhainds, Marc DeMerchant, Ian Therrien, Pierre eng England 2021/02/04 J Econ Entomol. 2021 Apr 13; 114(2):769-775. doi: 10.1093/jee/toaa275" |
