Wednesday, August 31, 2016

Black Swallowtail Paint Job

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Black Swallowtail - Chris Barnhart
Amy Tyndall brought this beauty into the Butterfly House for identification.  It probably is familiar to some of you Butterfly House docents and lepidopterophiles but just looks a little off.  Chris Barnhart identified it as an aberrant Black Swallowtail (BS), Papilio polyxenes asterius.  It looks like an chemically impaired painter did the markings.  Lets compare them to the normal BS (pardon the abbreviation.)

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

The ventral view above shows that the genetic painter hadn't sobered up yet when it turned the butterfly over.  Notice again that the discrete orange decorations are smeared as well as the white decorations on the wing and even the swallow tail.

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.

1 comment:

  1. Aberrant like this happen in nature, naturally. Releasing commercially raised butterflies doesn't cause harm to wild butterflies. This particular aberration won't live in the wild. It can't spread the gene. It won't have offspring. The veins in the lower half of the hind wings aren't there. It can't fly well enough to live live enough to mate.

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