The Pehuén District is in the sub-Antarctic forests of Argentina, between 37º 48’ S and 40º S, and varies greatly in distance from its border with Chile in the east. The area of Moquehue represents the climax communities in this district. The presence of the dominant species, Araucaria araucana (Mol.) Koch (Araucariaceae), Nothofagusdombeyi (Mirb.) Oerst, N. pumilio (Poepp. et Endl.) Krasser, and N. antarctica (Forst. F.) Oerst (Fagaceae) is their main characteristic. The entomofauna and its relationships with the flora of this area have been studied for several years. This is the second paper describing the Lepidoptera of this area. The insect species detailed here are from 14 families, and four of these are recorded for the first time. Forty-one species, not previously found in the area, are recorded here for first time, together with novel phenomena for 32 other species relating to collection and flight times, locations, and hosts. Of the newly recorded species, 24 are associated with Nothofagus species, 13 with other indigenous woody species, eight with exotic woody species, 22 with native herbaceous plants, seven are polyphagous, and the relationships of 22 species are still unknown. Two species are associated with A. araucana, the first to be identified since observations began. The presence of Ormiscodesschmidtnielseni Lemaire (Saturniidae) is reported for the first time in Argentina.