Abstract
A unique case of sex-limited mimicry occurs in the eastern Tiger Swallowtail butterfly, Papilio glaucus (L.). The females of this species occur in two morphs: A black form mimics Battus philenor (L.), a black butterfly species which is unpalatable to avian predators (Brower, 1958; Platt et al., 1971); a nonmimetic yellow form is similar to the male coloration. Males are not mimetic, occurring only in the yellow form. This sex-limited dimorphism is found largely in P. glaucus populations which are sympatric with B. philenor. Brower and Brower (1962) and Burns (1966) have summarized the literature on the distribution of these two species. This mimetic polymorphism is unique in that evidence indicates that the locus which controls it is on the Y-chromosome (Clarke and Sheppard, 1962b). To date, the simplest hypothesis explaining the existing data is complete Y-linkage, with occasional segregating broods resulting from some chromosomal abnormality. Thus, this dimorphism cannot be maintained by heterozygote advantage. The maintenance of this dimorphism in populations of P. glaucus sympatric with B. philenor has generated considerable discussion. Clarke and Sheppard (1962b) suggested that mimicry or a combination of mimicry and migration might account for the maintenance of the dimorphism.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
