|Black Swallowtail - Chris Barnhart|
|Aberrant Male BS- dorsal view|
|Male Black Swallowtail - Donald Hall|
All of the yellow decorations on the male on the left are blurry on the upper medial portion and frankly smeared into lines along the trailing edges.
|Aberrant ventral view -CB|
|Normal ventral - Donald Hall|
Aberrant butterflies can occur with extreme stress or nonlethal damage within the chrysalis. Consistent color changes in a small isolated breeding population can lead to distinctive "forms" as a result of persistent inbreeding.
The Monarch page of Butterflyfunfacts.com has pictures of aberrant Monarchs found in the breeding stock at Shady Oak Butterfly Farm. The mating of a normal and an aberrant produced a few aberrants. Two aberrants monarchs breeding produced all aberrants. This fun fact serves to illustrate just one of the dangers of inbreeding in commercially raised populations. For this reason we discourage the release of commercially propagated butterflies by well-meaning people at the Roston Butterfly House.