The Relationship Between Trembling Aspen Phenology and Larval Development of the Large Aspen Tortrix

📖 The Scoop

The large aspen tortrix, Choristoneura conflictana (Walker), is an occasional defoliator of trembling aspen, Populus tremuloides Michx. in western Canada. Although the essential details of its life cycle are well known, the development of the insect with respect to its host plant is poorly understood. Large aspen tortrix and trembling aspen bud and shoot development are described from observations at two sites in 1994. Degree-day models based on a common threshold temperature of 5 C were developed for both insect and bud and shoot development of its host. Parameter estimates for models of aspen development suggest that there is considerable variation in budbreak between sites, whereas C. conflictana exhibited less variation of this kind. Parameter estimates for C. conflictana development models were somewhat at odds with plots of the raw data for the onset of feeding. Clonal control of phenological development of aspen and microsite differences in temperature regimes are among the phenomena that must be considered if the models to predict phenological events accurately in the field are to be improved.

Genre: Technology & Engineering / Agriculture / Forestry (fancy, right?)