A heartbreaking and dismaying scene greets the eye on Ontario’s Spanish River, near Sudbury, Ontario. The river’s edge and surrounding slopes are lined with dead, grey skeletons, the victims of a huge, ongoing outbreak of spruce budworm. Spruce budworm is a highly destructive parasite whose larvae feed on the buds and needles of white and black spruce and balsam fir, the dominant species in the boreal forest. While a tree may survive a year or two of infestation, three or mor