Management of the hemlock looper (HL) in a changing environment


Historically, HL has defoliated >1 million ha of forest thereby causing millions of m3 in wood lost, at both ends of Canada. HL is also the first of our indigenous forest pests to show a real northern extension of its range, at least, in eastern Canada. This component will provide the basic knowledge required to generate forest management tools aimed to improve the timing of suppressive pest control tactics against HL, including natural enemies, under different climate scenarios.


  1. Assessment of HL growth under different climate scenarios (insect phenology). Effective insect control strategies aim to synchronize the timing of suppressive tactics with the most susceptible developmental stage of pest targets. Findings on HL growth will serve to generate a phenology model, providing forest managers with a tool to best time application of any control agents.
  2. Assessment of reproduction under different climate scenarios (population dynamics). Population dynamics model is an effective tool to predict when outbreak density will occur within insect cycle. Estimates of the potential increase of HL populations, through reproduction, is a major component of population model, which provides managers lead time to plan operational control program.
  3. Assessment of mortality under different climate scenarios (population dynamics). Assessment of mortality rates is another critical component for modelling HL population dynamics. Impacts of several ecological factors (parasitoids, temperature) on HL mortality will be assessed to provide estimates of future risk of damage by HL in response to climate.
  4. Guide of parasitoids complex of hemlock looper. To synthesize the knowledge acquired on the natural enemy complex of HL populations in Canada, a document illustrating the most common parasitoids of this species will be produced. This practical guide will serve both forest managers and scientists.


  • Department of Natural Resources (DNR) of Nova Scotia
  • DNR Newfoundland and Labrador
  • Ministère des Ressources naturelles et de la Faune du Québec (MRNF)
  • Conseil de l’industrie forestière du Québec (CIFQ)
  • Société de protection des forêts contre les insectes et maladies (SOPFIM) (Qc);
  • Université Laval (Qc)