The parasitism of the yellow-headed spruce sawfly, Pikonema alaskensis (Roh.), was studied in the course of investigations on the control of the sawfly in farm shelter-belts. Although some of the chemical control measures used against the sawfly destroyed its parasites, others did not. A knowledge of the parasites and their abundance in the study area became necessary. Since most of the parasites known to attack the sawfly emerge from the cocoons, this stage of the host was investigated first.