Heliconius cydno is a polytypic species ranging from southern Mexico to western Ecuador, with a number of closely-related entities (including H. pachinus, H. heurippa, H. timareta and H. tristero) that have been described as separate species but may be differentiated geographical races or the results of introgressive hybridization. Patterns of gene flow between races of H. cydno and races of its close relative H. melpomene are the subject of much current research