Find The Most Unusual Butterfly Only at the Academy of Natural Sciences

Posted on: January 21st, 2015 by

This post was sponsored by The Academy of Natural Sciences who is a Jersey Family Fun Partner in Fun. We appreciate their support of Jersey Family Fun that allows us to share with families information about things to do with families in Philadelphia & Philadelphia Museums we think your family may enjoy.


A week or so this press release from the Academy of Natural Sciences landed in my inbox and I was so fascinated by it that I had to share it with all of you. Can you imagine this happening to you at work? What if one day, in your normal day to day activities at work, you stumbled across something so unique and fabulous that you can’t even believe it to be true? How would you react?


This is just what happened to Chris Johnson, an Academy of Natural Sciences volunteer, a few months back. Take a look at this incredible story.


From the Academy of Natural Science’s press release

Chris Johnson was on the final task of his to-do list before the museum opened to the public when 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.” What the volunteer in the Butterflies! exhibit at the Academy of Natural Sciences of Drexel University saw was an extremely unusual butterfly—emerged just hours before from its chrysalis—spreading its delicate wings wide to reveal that it was exactly half male and half female.


Its two right wings—brown with yellow and white spots—were characteristic of a female of the species, and its two left wings—darker with green, blue and purple coloring—were typical of a male. The right wings were shaped differently than the left wings, and the body’s coloration was exactly split lengthwise down the middle as half male and half female.


The right wings of this preserved Lexias pardais are characteristic of the female of the species and the left wings are typical of the male. The body’s coloration is exactly split down the middle lengthwise. Photo J.D. Weintraub/ANSP Entomology

The right wings of this preserved Lexias pardais are characteristic of the female of the species and the left wings are typical of the male. The body’s coloration is exactly split down the middle lengthwise.
Photo J.D. Weintraub/ANSP Entomology


“It slowly opened up, and the wings were so dramatically different, it was immediately apparent what it was,” said Johnson, a retired chemical engineer from Swarthmore, Pa., who spotted the delicate creature one day in October as he was emptying the Butterflies! exhibit’s pupa chamber. The pupa chamber is where exhibit staff place the chrysalises and cocoons that are shipped from overseas in order to allow the butterflies and moths inside to develop and emerge properly. Then they are released into the exhibit.


Johnson and his supervisor, Butterflies! Coordinator David Schloss, carefully isolated the butterfly and contacted Entomology Collection Manager Jason Weintraub, a lepidopterist. They knew it was important to save the butterfly for research by turning it over to Weintraub rather than let it loose in the exhibit, and run the risk of something happening to it during the handful of days it would live there.


Weintraub immediately confirmed Johnson’s suspicion. The butterfly was Lexias pardalis, and it had an unusual condition called bilateral gynandromorphy.


The Academy of Natural Sciences has this butterfly on display this butterfly until February 16, 2015.


What is Gynandromorphism?

“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,” Weintraub said. This condition is extremely rare, but scientists don’t know just how rare it is because it is usually overlooked in most species where the two sexes look similar to one another.


So how did this unusual butterfly end up at the Academy?

This particular Lexias pardalis (butterfly) had been shipped in October as one pupa among many from a sustainable butterfly farm on Penang Island in Malaysia. Similar farms in Costa Rica, Kenya and the Philippines also keep the Butterflies! exhibit supplied with pupae that then transform into butterflies.


Lexias pardalis does not have a standard ordinary name, but it is a member of the butterfly family Nymphalidae, commonly known as “brush-footed” butterflies. Lexias butterflies live in tropical rainforests of Southeast Asia. The males sport iridescent black, greenish-blue wings, while females are larger and have brown wings with yellow and white spots.


How are unique species like this usually discovered?

“In most cases, such specimens are ‘discovered’ in museum collections by a researcher who is carefully examining reproductive organs of insects under the microscope and stumbles across a specimen with both male and female characteristics,” Weintraub said.

For Johnson, a naturalist and Academy volunteer for more than five years, his discovery was a thrill of a lifetime. “It’s something when you realize how special a phenomenon it is,” he said.


This special unusual butterfly—preserved and pinned—will be on display at the Academy for visitors to see from Saturday, Jan. 17, through Monday, Feb. 16.  Get your kids down there to see something that is truly unique.


Academy of Natural Sciences Hours:

  • Monday-Friday 10am to 4:30 pm
  • Saturday & Sunday 10am to 5 pm


Academy of Natural Sciences Location:

The Academy of Natural Sciences is located at 1900 Benjamin Franklin Parkway in Philadelphia, Pennsylvania.


Read more about The Academy of Natural Sciences by checking out our The Academy of Natural Sciences series. You can also visit our Academy of Natural Sciences videos on our YouTube Channel.


In full disclosure, The Academy of Natural Sciences is a Partner in Fun with Jersey Family Fun. These articles are included in their advertising package, but all opinions are our own based on our experience at The Academy of Natural Sciences.  To become one of our Partners in Fun, please contact

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