Monoctenus sanchezi is a sawfly of economic importance in forest management because of damage to the foliage of white cedar. Mortality by entomopathogenic fungi Metarhizium anisopliae, Beauveria bassiana, and Trichothecium sp. on M. sanchezi larvae was 98, 60, and 36% on the sixth day. Metarhizium anisopliae may be an alternative for biological control of the sawfly in México.