Heliconius melpomene, the postman butterfly, common postman or simply postman, is a brightly colored, geographically variable butterfly species found throughout Central and South America. It was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Its coloration coevolved with another member of the genus, H. erato as a warning to predators of its inedibility; this is an example of Müllerian mimicry. H. melpomene was one of the first butterfly species observed to forage for pollen, a behavior that is common in other insect groups but rare in butterflies. Because of the recent rapid evolutionary radiation of the genus Heliconius and overlapping of its habitat with other related species, H. melpomene has been the subject of extensive study on speciation and hybridization. These hybrids tend to have low fitness as they look different from the original species and no longer exhibit Müllerian mimicry.

Heliconius erato, or the red postman, is one of about 40 neotropical species of butterfly belonging to the genus Heliconius. It is also commonly known as the small postman, the red passion flower butterfly, or the crimson-patched longwing. It was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.