For the first time in nearly three decades, scientists have discovered a new species of Alaskan butterfly. Dubbed Oeneis tanana, or the Tanana Arctic, the insect may be the only butterfly endemic to Alaska, where it has evolved to survive the state’s extreme seasonal variability and cold temperatures.
The butterfly, described in a new study published in the Journal of Research on the Lepidoptera, is speculated to be a hybrid butterfly species—the result of interbreeding between two previously known lineages called Oeneis bore, aka the White-veined Arctic, and Oeneis chryxus, aka the Brown Arctic.
The Tanana river, namesake of the Tanana Arctic. Image: Liz from Fairbanks, AK
According to University of Florida lepidopterist Andrew Warren, the lead author of the new study, the Tanana Arctic is distinct from both these alternate Arctic butterflies, though it shares many inherited features from them, especially O. chryxus.
For instance, the new species has sepia-toned wings with a dappled underside of white speckles, like other neighboring butterflies, and also shares the ability to produce antifreeze-like substances in its blood to stave off punishing Alaskan temperatures.
Oeneis tanana sample. Image: Andrew Warren/Florida Museum of Natural History
Further insights are likely coming down the pipeline, as genomic analysis of this hardy insect comes to a completion. "Once we sequence the genome, we'll be able to say whether any special traits helped the butterfly survive in harsh environments," Warren said in a statement.
"This study is just the first of what will undoubtedly be many on this cool butterfly."
To that point, the Tanana Arctic could be a useful species for understanding both the past and the future of Alaska’s lush and ever-changing ecosystems. Its evolutionary history could help lepidopterists fill out the picture of butterfly migration from Eastern Asia and Russia into North America over the last 30,000 years.
Meanwhile, the butterfly’s reaction to the pressures of human-driven climate change can inform scientists about the severity of climate-related ecological upheaval in Alaska’s wild reaches.
"This butterfly has apparently lived in the Tanana River valley for so long that if it ever moves out, we'll be able to say 'Wow, there are some changes happening,'" Warren said. "This is a region where the permafrost is already melting and the climate is changing."
On a more overarching level, the discovery of this unique hybrid breed of Alaskan butterfly shows that there is still a lot left to learn about Arctic ecosystems.
"New butterflies are not discovered very often in the U.S. because our fauna is relatively well-known," Warren said. "But with the complex geography in the western US, there are still going to be some surprises."