JULY 2013 - A strange insect collected by UAF graduate student Jill Stockbridge during her thesis research on Prince of Wales Island is a new species of snow scorpionfly. UA Museum of the North Curator of Insects Derek Sikes says it belongs to an enigmatic group that might help scientists understand the evolutionary origin of fleas.

"In addition to being the second known species of an usual group of insects, we were excited to learn from fossil evidence that these two species belong to a group that probably dates back over 145 million years, to the Jurassic," Sikes says.

The specimens were collected on Prince of Wales Island, which is part of the Tongass National Forest, a coastal rainforest that’s home to huge Sitka spruce, cedar, and hemlock. Stockbridge is comparing different forestry practices by sampling beetles and spiders in the ecosystem.

“Along with old growth forests, you also see clear cut areas as well as secondary growth where the trees are returning,” she said. “Forest management has been coming into the secondary growth to thin out the trees to try to speed up the recovery process, because it can take more than 120 years to complete that cycle.”

Stockbridge got stuck when she tried to identify the tiny flea-like insects she’d found. She turned to her thesis advisor Sikes, who was equally baffled. He posted a digital photo on Facebook to see if any of his entomologist friends could offer an opinion. Most of the suggestions were wrong, but one scientist, Michael Ivie, recognized that the specimen belonged to the genus Caurinus, of which only one species was previously known.

The researchers named the species Caurinus tlagu for the Tlingit tribes who have lived on the northern half of Prince of Wales Island for thousands of years. “In their honor we chose a Tlingit name,” Stockbridge said. “The word tlagu means ancient, which we thought was appropriate since this creature has been around since the Jurassic.”

The tiny two-millimeter long animals are members of the insect order Mecoptera, which includes the scorpionflies, hangingflies, and snow scorpionflies. Although they have biting mouthparts they feed on a leafy liverwort found in coastal forests rather than sucking blood like fleas. However, they hop like fleas, are the size and color of fleas, and even have the same shape when viewed from the side.

Genetic data suggests that this group might be closely related to the fleas, making these non-parasitic insects potentially valuable in understanding the origin of their parasitic relatives.

Sikes and Stockbridge published the species description recently in the open access journal ZooKeys.