Eresia lansdorfi, the false erato or Lansdorf´s crescent, is a butterfly of the family Nymphalidae.

 Eresia lansdorfi has a wingspan of about 60 mm. The upperside of the wings is black. The forewings have a yellowish basal stripe, while the postdiscal area is light red brown, including the costal bar. The hindwings have a pale yellow transverse band.

This medium-sized species imitates (Batesian mimicry) two local subspecies of Heliconius erato (hence the common name) and Heliconius melpomene.

Larvae feed on Ruellia brevifolia.

Distribution: This species can be found in Brazil, Northern Argentina, Paraguay, Uruguay and Peru.