A very rare butterfly hatched from its chrysalis at the Academy of Natural Sciences of Drexel University, a museum located in Philadelphia, Pennsylvania.
It was museum volunteer Chris Johnson, who works in the Butterflies! exhibit at the Academy, who noticed the butterfly first. When he saw the delicate wings of the butterfly spread wide to reveal just how unusual it was, Johnson said he stopped dead in his tracks.
“I thought: ‘Somebody’s fooling with me. It’s just too perfect,” recalled Johnson. “Then I got goose bumps.”
The two right wings of the butterfly were brown with yellow and white spots, which are characteristic of a female butterfly of the species. But the two left wings were not just shaped differently than the right, they were darker in color, with green, blue and purple markings, characteristic for the male butterfly of the species.
And the body of the unusual butterfly was likewise split lengthwise right down the middle, displaying one half characteristic of a female, while the other half was male.
“It slowly opened up, and the wings were so dramatically different, it was immediately apparent what it was,” said Johnson, who is a retired chemical engineer.
He discovered the unusual butterfly in the exhibit’s pupa chamber, which is where exhibit staff place the chrysalises and cocoons that are shipped from overseas. The pupa chamber allows the butterflies and moths inside to develop and emerge properly, and they are then released into the exhibit.
This one, however, was not released into the general butterfly population. It was too much of a risk to let the rare butterfly loose in the exhibit and risk something happening to it during the few days it would live there. According to the Academy’s press release, Johnson and his supervisor, Butterflies! coordinator David Schloss, carefully isolated the butterfly before contacting Entomology Collection Manager Jason Weintraub. Weintraub is a lepidopterist, which is a zoologist who deals with moths and butterflies.
Weintraub immediately confirmed Johnson’s suspicion. The butterfly was Lexias pardalis, which are found in Thailand, and it had an unusual condition called bilateral gynandromorphy. In other words, the butterfly was exactly half-male, and half-female. It’s a rare condition most commonly noticed in birds and insects because males and females often have different color patterns.
The butterfly has been preserved, and will be put on display for a limited time.
According to the Academy, “Preserving the unusual specimen in the Entomology Collection provides scientists with an important source of information for the study of comparative morphology, anatomy and evolution—an important reason why natural history research collections such as the extensive ones at the Academy are so important.”
[Images via pixgood.com and ansp.org]