North Central forest insectsThis article is part of a larger document. View the larger document here.
This chapter describes three projects. One project addressed the impacts on American basswood (Tilia americana) from an exotic species, the introduced basswood thrips (Thrips calcaratus). As with many exotic species, little was known about the biology and behavior of this insect, and little was known concerning the possible negative impacts on the basswood resource in the North Central region. The project clarified the importance of Thrips calcaratus in a regional basswood decline episode. It also provided a great deal of basic biological information on the insect. The second project studied the responses of sub-boreal forest insect communities to a large windstorm and subsequent salvage activities and prescribed burning in northeastern Minnesota. Study results indicated that subcortical insect numbers and activity increased initially in the wind-disturbed areas, and contributed to the mortality of live residual trees after the windstorm, but subcortical insect numbers declined dramatically 4 years after the windstorm, and a widespread epidemic of bark and woodboring insects did not occur in these sub-boreal forests. The third study revolved around the evaluation of survey methodology for forest defoliators. This project proposed the development of a multi-scale approach to monitor defoliation extent and severity using high-resolution satellite imagery. Specific objectives were to link image-derived estimates of defoliation to measures derived from current forest health Detection Monitoring (DM) efforts (i.e., aerial survey). This research could pave the way towards standardized defoliation mapping using satellite-based methods.