POPULATION STUDIES OF THE EUROPEAN SPRUCE SAWFLY (Gilpinia hercyniae Htg.) IN QUEBEC

Abstract

The author devoted three summers in the field to a study of the population of the European Spruce Sawfly in Quebec using the large sample plot method. His findings indicated:(a) that the depth of the humus affected the emergence of the adult from the cocoon;(b) that sunlight encourages emergence;(c) that humidity increases emergence and reduces mortality;(d) that small mammals constitute a more important control agent of the insect, at the present time, than parasites; and,(c) defoliation by the insect results in a marked decline in growth rate.