The male and female Parides eurimedes are primarily black with a red patch on the hindwing.
Both sexes lack tails.
The upper surface of the male forewing has a triangular blue-green patch whereas the female has a white patch (like on the photos).
Its wingspan is 7 - 8.5 cm.
Andrew Neild, author of The Butterflies of Venezuela and a recognized authority on Neotropical butterflies, helped me identifying this species.
A female. Los Tarrales Natural Reserve, Patulul, Suchitepequez, Guatemala, 18 January 2020