Abstract
One of the objects of the investigations on the European spruce sawfly, Gilpinia hercyniae (Htg.), in Eastern Canada was to discover and evaluate the factors of natural control affecting this introduced species in its new environment. Small mammal predators were found to be the most important factor affecting the sawfly cocoons, which were spun in the moss or litter of the forest floor (4, 5). These predators chewed large openings in the cocoons and pulled out the contents. Cocoons were also found with smaller openings made by the entry of insect predators, and occasionally such a cocoon was found with a larva of the family Elateridae partly inside (Fig. 1).