Idaea tristega is a moth of the family Geometridae. It is found in northern Madagascar.afromoths

This species is very variable in size and warmth of the ground-colour. It is tinged reddish to cinnamon-brown with a wingspan of 14-22mm.Prout, L. B. 1932c. New genera and species of Sterrhinae (Fam. Geometridae). - Novitates Zoologicae 37:229–251 - on page 247

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