Chris Johnson was volunteering at the university’s Natural Science exhibit, Butterflies! in October of 2014. Luckily, he was watching when a butterfly, newly emerged from the chrysalis began to open its wings.
In a statement, Johnson said he saw right away that the two right wings of the butterfly were brown with white and yellow spots, and the two left wings were much darker, with blue and purple spots. He knew right away what he was witnessing. “The wings were so dramatically different, it was immediately apparent what it was,” said Johnson. “Then I got goose bumps.”
What Johnson, a retired chemical engineer from nearby Swarthmore, Pennsylvania, was looking at was a half-male, half female butterfly. The butterfly had the larger right wings of the female of the species, with dull brown coloration, and smaller left wings showing the brighter coloration typical in male butterflies of the species.
Drexel’s Entomology Collection Manager Jason Weintraub was immediately contacted after the butterfly was isolated. Experts determined the butterfly was a Common Archduke butterfly (Lexias pardalis), exhibiting an unusual condition called gynandromorphy.
Gynandromorphy is having outward signs of both male and female characteristics. This is different from hermaphroditism, where both male and female reproductive organs are present, but the organism shows only one sex externally. In the case of the butterfly, it was exhibiting bilateral asymmetry, one side male and the other side female.
“Gynandromorphism is most frequently noticed in bird and butterfly species where the two sexes have very different coloration. It can result from non-disjunction of sex chromosomes, an error that sometimes occurs during the division of chromosomes at a very early stage of development,” said Weintraub, as reported in the Daily Mail.
The Common Archduke butterfly belongs to the family Nymphalidae, known as “brush-footed” butterflies. The Archdukes belong in the genus Lexias, and there are 17 different species, with the largest species having a wingspan of four inches. These butterflies are found in the tropical rainforests of Southeast Asia.
L. pardalis is one of the more colorful of the Archduke butterflies, and one of several Archdukes raised on butterfly farms for export to conservatories and specimen collectors. The rare specimen found at Drexel was preserved and pinned after its death, and will be on display at the Academy of Natural Sciences of Drexel University from Jan. 17 through Feb. 16, according to academy staff.
