Dr. David Lees from the Department of Zoology of the University of Cambridge, United Kingdom, helped me identifying this species.
According to David, this is very likely Heteropsis andasibe.
This species can only be distinquished from other Heteropsis species by the pattern on the underside of the wings.
I met David in Madagascar in January 2014 during his research work in Andasibe-Mantadia NP and had the pleasure to spent a few days together.
David has extensive field research experience in Madagascar and is considered the leading expert on Madagascar butterflies.

Andasibe-Mantadia National Park, Madagascar, 11 January 2014