The Lava Bear is just a myth, and nobody’s ever proven Bigfoot is real, but the High Desert’s most enigmatic zoological phenomenon is back.
The Pandora moth, a moth with a palm-sized wingspan, gray and pink wings, and fuzzy gray bodies marked with yellow stripes, began re-emerging in Central Oregon in recent weeks. Like most moths, they’re drawn to bright lights, and on a July night, there’s no larger collection of bright lights in the region than at Vince Genna Stadium during a Bend Elks home baseball game.
Jodi Sunitsch has been coming to Vince Genna Stadium since she was a kid in the 1980s and has worked concessions for the Elks for the past 12 seasons. She said she remembers past moth outbreaks at the ballpark, particularly in the 1990s, but nothing like she saw during this week’s series against the Bellingham Bells.
As the sun went down the moths came to life, swarming around the stadium lights, Sunitsch said. By late in the game, the moths had begun to congregate on the screen behind home plate, she said, and every time a batter fouled a pitch backward, a scattering of moths rained down on the shrieking crowd.
“In the 12 summers I’ve been here, this is by far the most moths I’ve seen,” she said.
Sunitsch said after the end of Tuesday’s game — the Elks beat Bellingham, 10-0 — the stadium lights went dark, and she and other stadium employees gathered on the patio on the third base line for a beer and a chat.
By the time they were ready to head home, what seemed to be the stadium’s entire moth population had moved to the only three lights still on, illuminating the corridor between the field house and the parking lot.
Sunitsch said she and the rest of the staff were led through the back warrens of the field house, to avoid having to run the moth gantlet between them and their waiting cars.
Elks General Manager Michael Hirko arrived at the stadium Wednesday morning, expecting to spend at least part of his day sweeping away dead moths. When he found thousands of moths littering the walkway between the bleachers and the field house, he fetched the team’s gas-powered leaf blower instead.
By midday Wednesday, there was little indication any cleanup had taken place at all, with hundreds more carcasses littering the corridor by the field house and scattered among discarded peanut shells up in the stands.
Hirko said the moths haven’t impeded play, but they seem to have run off the stadium’s bats — winged, not wooden — leading to an uptick in mosquito bites. More than anything, they’ve made his job of cleaning up the stadium even more tiresome.
“It’s just tedious and annoying,” he said. “They’re just everywhere.”
Rob Flowers, entomologist with the Deschutes National Forest, said this year is only the beginning.
The eggs moths lay this year will return in 2018 as caterpillars, Flowers said, and in 2019, Central Oregon residents should see even more moths than they’re seeing this year.
The moths follow a somewhat predictable cycle, Flowers said, with about six to eight years between outbreaks, during which their population expands rapidly. Moths can be found in the area in the years in between outbreaks, he said, but they’re few and far between as compared to the millions that emerge during an outbreak period.
A Pandora moth that manages to avoid being squished by a car or gobbled down by a bird will live for two years.
In even-numbered years, the young insects live as caterpillars, and head in to the trees where they devour the needles of ponderosa and lodgepole pine trees. Well fed, the caterpillars burrow in to the soil for the winter, and emerge again in odd numbered years as moths, congregating around bright lights, mating, and by the end of summer, dying.
Moths are continuing to emerge from the soil, Flowers said. He said he was in the woods near Phil’s Trail earlier in the week, where squirrels were feasting on still-groggy moths digging out of their winter burrows.
Each outbreak typically lasts three to four generations, Flowers said, playing out over the course of six or eight years.
Flowers said by studying tree rings, researchers have been able to determine Pandora moths have stuck to a similar pattern in the Cascades for hundreds of years. The rings show slower growth for ponderosas and lodgepoles in years when the caterpillars were active, while junipers and other trees not consumed by the caterpillars are unaffected.
The caterpillars don’t appear to significantly damage the trees they feed on, Flowers said, as they prefer year-old needles to new growth. He said in some cases, Pandora moths may leave a stand of trees more vulnerable to unrelated, more damaging insects such as the mountain pine beetle.
While in their moth stage, the Pandora does not eat, surviving on stored energy during the short period between emergence, mating and death. Flowers said if past patterns prevail, the moths will be largely gone by mid-August.
Despite being able to draw on such a long history, Flowers said entomologists are still unclear as to why the moth population explodes every few years only to decline again.
Flowers said one of the leading theories involves a virus active in the moth population. When the larvae become sufficiently numerous, they’re likely to be in closer contact with each other, he said, allowing the virus to be rapidly transmitted through the population. All but a few die off, keeping the population going until a new outbreak begins a few generations later.
The moths are harmless to people, pets and plants, Flowers said, suggesting residents keep porch lights out and screens closed if they wish to avoid them.
The caterpillars and pupae — the intermediate stage between caterpillar and moth — were historically used as a food source by the Northern Paiute and other Native American tribes in the West, typically roasted in hot sand, according to the Oregon Department of Forestry.
Back at Vince Genna Stadium, the Elks are hoping the moth population ebbs before the team’s next series of home games begins July 19. Maybe having the stadium lights dark for a week will encourage the swarm to move elsewhere, Sunitsch said, or maybe they’ll just die off on their own.
Assuming they’re still around, the team will make the best of it, Hirko said. Fans shouldn’t shy away from the stadium on account of the moths, he said, adding that if a moth lands in your beer — and you ask nicely — you can probably get a free refill.
— Reporter: 541-383-0387, email@example.com