Total nestbound population was estimated to be 56 million individuals. The authors calculated that this population would require at least 470 kg dry weight of food annually, which is about 11 times the total dry weight of western spruce budworm that might occur during an outbreak. Ants, important predators of the western spruce budworm, require sufficient down wood in a range of sizes and decomposition stages. Torgersen, T. R. and E. L. Bull. Down logs, important habitat for forest-dwelling ants, were examined for their key characteristics and the species of ants using them.
Ants are also an important food source for pileated woodpeckers.
Six logs per plot were sectioned to collect ant specimens. Ants were grouped into Camponotus species, Formica species, and other species. Lasius alienus was the most common, followed by Formica neorufibarbis and Camponotus modoc . Camponotus ants occurred significantly more frequently in logs of the largest diameter class. The authors report that three Camponotus and three Formica species identified in this study are known to be predators of western spruce budworm.