Rare insect found at Arkansas Walmart sets historic record, points to deeper ecological questions

This Polystoechotes punctata or giant lacewing was collected in Fayetteville, Arkansas in 2012 by Michael Skvarla, director of Penn State’s Insect Identification Lab. The specimen is the first of its kind recorded in eastern North America in over fifty years – and the first record of the species ever in the state. Credit: Michael Skvarla/Penn State

A giant insect plucked from the facade of a Walmart in Arkansas has set historical records. Polystoechotes punctata (giant lacewing) is the first of its kind to be recorded in eastern North America in over 50 years – and the first record of the species ever in the state.

The giant snow fox was once widespread throughout North America, but was mysteriously extirpated from eastern North America in the 1950s. This discovery suggests that there may be relict populations of this large insect from the Jurassic era that have yet to be discovered, explained Michael Skvarla, director of Penn State’s Insect Identification Lab.

Skvarla found the specimen in 2012 but misidentified it and only discovered its true identity after teaching an online course based on his personal insect collection in 2020. He recently co-authored a paper on the discovery in Proceedings of the Entomological Society of Washington.

“I remember it clearly, because I went into Walmart to get milk and I saw this huge bug on the side of the building,” said Skvarla, who was a graduate student at the University of Arkansas at the time. “I thought it looked interesting, so I put it in my hand and did the rest of the shopping with it between my fingers. I got home, mounted it and promptly forgot about it for almost a decade.”

It wasn’t until the COVID-19 pandemic that the giant snow fox would find its time to shine. In fall 2020, with the world on lockdown, Skvarla taught Entomology 432: Insect Biodiversity and Evolution at Penn State. He taught the lab course via Zoom, with students watching remotely on loan microscopes, and using his own personal insect collection as test specimens.

When he went to demonstrate the features of a specimen he had previously labeled a “mylion”, Skvarla noticed that the features did not quite match those of the dragonfly-like predatory insect. Instead, he thought it looked more like a shoelace. A giant lacewing has a wingspan of about 50 millimeters, which is quite large for an insect, a clear indicator that the specimen was not a marsh lion, as Skvarla had mistakenly labeled it. The students started comparing features – and a discovery was made, live on Zoom.

“We looked at what Dr. Skvarla saw under his microscope, and he talks about the features and then he stops a little bit,” said Codey Mathis, a doctoral candidate in entomology at Penn State. “We all realized that the insect was not what it was labeled and that it was actually a super-rare giant lacewing. I still remember the feeling. It was so gratifying to know that the excitement is not dampening, the wonder is not. lost. Here we did a true discovery in the middle of an online lab course.”

For further confirmation, Skvarla and his colleagues performed molecular DNA analyzes on the sample. Since confirming its true identity, Skvarla has deposited the insect safely in the collections of the Frost Entomological Museum at Penn State, where researchers and students will have access to it for further research.

“It was one of those experiences you don’t expect to have in a prerequisite lab course,” Louis Nastasi, a doctoral candidate studying entomology at Penn State. “Here we were just looking at specimens to identify them, and suddenly, out of nowhere, this incredible new record appears.”

Discovery or recovery?

The fact that a giant lacewing was discovered in the urban area of ​​Fayetteville, Arkansas, may reveal a larger story about biodiversity and a changing environment, Skvarla explained. He said explanations vary for the giant lacewing’s disappearance from North America — and it remains largely a mystery.

Scientists hypothesize that the insect’s disappearance may be due to the ever-increasing amount of artificial light and pollution of urbanization; forest fire suppression in eastern North America, if the insects depend on post-fire environments; the introduction of non-native predators such as large ground beetles; and the introduction of non-native earthworms, which significantly altered the composition of forest leaf litter and soil.

“Entomology can serve as a leading indicator of ecology,” Skvarla said. “The fact that this insect was discovered in a region where it hasn’t been seen for over half a century tells us something more general about the environment.”

The researchers analyzed extensive collection records of giant lacewings, including museum holdings and social science submissions, and placed them on a single map to determine their distribution. The records span a large geographic area, from Alaska to Panama, and include several ecoregions in both eastern and western North America. The map revealed that the Arkansas specimen was the first to be discovered in eastern North America in over 50 years.

Fayetteville lies within the Ozark Mountains, which are a suspected biodiversity hotspot, according to Skvarla and his co-author J. Ray Fisher of the Mississippi Entomological Museum at Mississippi State University.

They said dozens of endemic species, including 68 species of insects, are known from the Ozarks and at least 58 species of plants and animals have highly disjunct populations with representatives in the region. They explain that the area is understudied compared to regions with similar biodiversity, such as the southern Appalachians.

“This combination makes the region an ideal place for a large, showy insect to hide undetected,” they said.

The mystery remains as to how the insect arrived outside a Walmart. The fact that it was found on the side of a well-lit building at night suggests that it was probably attracted to the lights and may have flown at least a few hundred meters from where it originated, Skvarla explained. “It could have been 100 years since it was even in this area – and it’s years since it’s been spotted anywhere near it. The next closest place they’ve been found was 1,200 miles away, so highly unlikely it would have traveled as far.”

The researchers note that they suspect the new specimen represents a rare, surviving eastern population of giant lacewings that eluded detection and extinction.

“Discovery doesn’t always have the same kind of hold on people that it might have 100 years ago,” Nastasi said. “But a discovery like this really highlights that even in an ongoing situation, there is still a huge number of discoveries to be made about insects.”

More information:
Michael J. Skvarla et al, Rediscovery of Polystoechotes punctata (Fabricius, 1793) (Neuroptera: Ithonidae) in Eastern North America, Proceedings of the Entomological Society of Washington (2022). DOI: 10.4289/0013-8797.124.2.332

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