Two female specimens of Papilio thoas, the one on the left being the normal form of the species, while that on the right is a spectacular aberration. The latter was obtained from butterfly breeder and wildlife illustrator Mark Lightowler, who kindly provided the following information about it:
"The item is an extreme aberration of the common South American butterfly, Papilio thoas. The markings on this beautiful female specimen look more like its close relatives, Papilio ornythion and Papilio astyalus, fading the normal markings into total obscurity. This is the one and only specimen to emerge out of 150 pupae bred in May 1997 in my tropical greenhouse. The specimen is of large size measuring 10.5cm across and the underside markings are obsolete, giving the overall appearance of plain yellow wings. The specimen is in A1 condition and although mint bred, it does have a slight defect on the right hand forewing caused by a slight scale defect, from the pupa. However this is very minor and insignificant". In the twenty years or so of breeding Tropical species, I have never before come across an item so magnificent as this one".