Harvey the rare mutant cockroach, a prominent resident of the Sophia M. Sachs Butterfly House in St. Louis, died late last year. He was likely about 2 years old, a "geriatric" age for a roach, according to his human companions.
Harvey was an international scientific curiosity who may have been the only cockroach of his kind. His coloring was split in two along his abdomen, with one side a deep brown and the other a lighter, striped caramel.
"Everybody was incredibly excited to learn about Harvey, and no one had ever been able to point to any animal, any insect, any other cockroach that exhibited the same traits Harvey did," said Tad Yankoski, senior entomologist at the Butterfly House. "It appears that Harvey was unique."
Despite the attention to Harvey, the scientific community is still not sure exactly why he developed this way. It's safe to say he was a genetic mutant of some kind, Yankoski said, but it would take testing to know the exact type of mutation.
"Every single geneticist that we talked to was very excited to learn more about him," Yankoski said. "It's sort of a running joke that the people who studied point-source mutation were pretty sure that it must be a point-source mutation. The people who studied gynandromorphism were pretty confident it must have been caused by gynandromorphism, but I think that just shows how much of a mystery Harvey was."
The Butterfly House has preserved Harvey's remains and hopes to eventually solve the mystery through genetic testing, but Yankoski said outside experts are still researching the best way to do that.
"When that door does open, we'll be ready to go through it and hopefully unlock some of the mysteries of Harvey that are still unknown," Yankoski said.
Harvey spent his early life outside of the spotlight, living in obscurity in a colony of thousands of Madagascar hissing cockroaches at the Butterfly House. In March 2024, invertebrate keeper Nicole Pruess discovered Harvey during a routine feeding.
"I saw him and I was like, 'Oh, my gosh, that's so cool, I've never seen anything like it before,'" Pruess said at the time.
The Butterfly House staff named Harvey after the DC Comics character Two-Face. He was already an adult when he was discovered, so he was estimated to be between 3 and 6 months old.
"When we found him, we thought there was a chance that he might molt and not be successful, and that his days may be numbered," Yankoski said. "To our surprise, and a joyful surprise, he lived for over a year after we found him."
After he rose to prominence, Harvey lived in a penthouse aquarium near a window where Butterfly House visitors could see him up close. People often visited just to see Harvey, Yankoski said, and many took selfies with him.
"I think he was a great ambassador for insects as a whole," Yankoski said. "Not many people would go out of their way to see a cockroach, but they were excited to see Harvey and learn about him and ask questions about him."
Harvey leaves behind thousands of cousins at the Butterfly House, but to the staff's knowledge, he never fathered any offspring and would likely have been unable to do so because of his mutation. He also leaves behind many admirers.
"I think Harvey represents that there are discoveries to be made all around us. And if it wasn't for a keen-eyed individual when we were doing the feeding, we may have missed Harvey," Yankoski said. "There's been other discoveries recently that happened in the wild around St. Louis, like a white monarch butterfly. … Taking the time to appreciate what's in front of you can lead to really exciting discoveries, even in areas where you wouldn't expect them."
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