Abnormalities of wing pattern in the Eastern Tiger Swallowtail butterfly, Papilio glaucus

Abstract In much of its range Papilio glaucus L. has two forms of female, black and yellow, and the gene controlling the colour pattern is on the Y chromosome. Thus black mothers produce only black daughters and yellow mothers produce yellow daughters. Reasons are given to explain the occasional exceptions to this rule. The black female form mimics Battus philenor (L.), and an autosomal mutant is described in P.glaucus which is paralleled by a similar aberration in the model - a possible example of a model 'escaping' from a mimic and the mimic 'catching up' at one step.
Sex mosaics are readily seen in the black form of glaucus females and a numberare described from the Strecker collection. The probable cytogenetic constitution of these aberrations is discussed.
Hybrids are described between glaucus and its near relatives, P.rutulus Lucas, P.eurymedon Lucas and P.multicaudatus Kirby. These crosses produce mainly males but, by the use of ecdysterone, females have been obtained in the cross between the black female form of glaucus and the male of rutulus .