Invasive fruit fly hits the Yakama Nation’s huckleberry fields

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By Josephine Woolington

September 24, 2025

A few years ago, as Elaine Harvey washed three gallons of freshly picked huckleberries, she noticed something startling: Worms wiggling out of the dark-purple fruits. 

Editor's Note: This article was originally published by High Country News. Used with permission. All rights reserved.

“We didn’t even know those were wormy when we were picking them,” said Harvey, a member of the Ḱamíłpa Band of the Yakama Nation. 

Over the decades, Harvey and others within the Yakama Nation have worked to defend the tribe’s treaty-protected huckleberries in southwestern Washington’s Gifford Pinchot National Forest from a variety of threats, including commercial pickers, tree encroachment from federal fire-suppression policies and, more recently, an invasive fruit fly, called the spotted wing drosophila. 

Unlike other fruit flies that target overripe fruits, the spotted wing, which is native to Southeast Asia, lays its eggs inside berries as they ripen. The larvae feed on the fruit, causing berries to soften and rot. “We didn’t want to eat them because there were so many worms — little larvae coming out,” Harvey said. “It was really gross.” 

Harvey brought the issue up to U.S. Forest Service officials repeatedly over the years, asking what they planned to do to stop the insect from spreading. They told her that they lacked the money to study it. 

So Harvey reached out to Jessica Black, director of the Center for Indigenous Health, Culture and the Environment at Heritage University, a private school on the Yakama Reservation in central Washington. It took years of work, federal funding and numerous partnerships, but this summer, five students from Heritage University and Northwest Indian College headed off to the high-elevation huckleberry fields to study the encroaching insects.

For 10 weeks starting in July, they gathered data from fruit fly traps in Yakama Reservation and Gifford Pinchot National Forest berry fields. They found 11 fruit flies in Gifford Pinchot’s Sawtooth Berry Fields. But they also found six of them on the reservation, in an area closed to non-tribal members — the first official documentation of the fruit fly on Yakama Nation lands. 

A fruit fly trap set by the students on the Yakama Nation Reservation. Carol Craig/Yakama Nation Review

Their study coincided with the Forest Service’s temporary prohibition on commercial huckleberry picking in Gifford Pinchot this summer. It’s the only national forest with a large-scale commercial program, and the decision came after years of complaints from tribal members and leaders like Harvey, who said that commercial pickers infringed on their treaty right to harvest berries. 

Despite the ban, tribal members saw some commercial pickers this season. But they also noticed an abundance of berries, with less competition. The Forest Service did not respond to multiple requests for comment on whether it has increased patrols in the berry fields, simply noting, in a written statement, that the “safety of visitors on the Gifford Pinchot National Forest is our priority, and we are working with local law enforcement.”

Earlier this year, agency officials said the fruit fly was one of reasons they closed the fields to commercial pickers. “We’ve heard from the tribe,” Erin Black, the Mount Adams District ranger at Gifford Pinchot, said in an interview last year. “We want to do what we can to ensure that this doesn’t become an infestation.”

Only one other study, led by Washington State University and Oregon State University researchers in 2013, has looked into the fly’s presence in huckleberry fields. It found that the most fly-infested berries grew at lower elevations, both in Gifford Pinchot and in Mount Hood national forests.

Fields on the Yakama Reservation are slightly higher in elevation than the Sawtooth Berry Fields, and the students found similar results. But the fly’s increased presence on the national forest may also stem from its higher visitation rates; the huckleberry fields have been open for decades to both recreational and commercial pickers. The Pacific Crest Trail also cuts through the area, and visitors may have unknowingly spread the fruit fly through packed lunches containing infested fruit, said Cyrus Dick, an invasive species biologist for the Yakama Nation. “I’m hoping we can solve this issue before it gets out of hand,” said Dick, who is also a member of the Yakama Nation. 

James Williams from Heritage University and Corey Edgar from Northwest Indian College check the status of a bait trap container. They pour contents into a smaller container to take back to the lab and inspect under a microscope. Carol Craig/Yakama Nation Review

The student-led study, which Dick oversaw, will help inform the Yakama Nation’s attempts to eradicate the fly on tribal land, he said. But since huckleberries are culturally sensitive, the tribe will not use herbicides or insecticides to kill the insects. “We have to find solutions outside of the norm,” he said. 

They’ve looked at experimental methods on organic farms that grow raspberries, strawberries and blueberries. Oregon State University researchers have studied parasitic wasps that prey only on spotted wing drosophilas and released some of them near Hood River, The Dalles and Salem. The wasps lay their eggs inside fruit fly larvae, where they grow until they eventually overtake the fly’s immune system. “It’s kind of like a horror movie,” Dick said, laughing. 

Most scientific reports about spotted wing drosophila address the insect’s impact on agricultural crops, as the tiny pest has wreaked havoc on Oregon’s commercial fruit industry, costing the blueberry industry alone more than $10 million in annual losses. But such studies may not provide any information that’s relevant to how the flies impact traditional foods like huckleberries, said Kyal Shoulderblade, a 24-year-old Yakama Nation member and environmental science student at Heritage University who was a part of the huckleberry study. “The papers we did read said that they needed more observation, more information,” Shoulderblade said. The students hope that their study is only the first of many. 

Dick said that he wants to create an annual internship program where students can gain scientific skills while also helping to inform the tribe’s management of its huckleberry fields. Their work could also influence the national forest’s management of the fruit fly problem. 

The students and their professors also hope to forge a new model for other tribal members to study culturally significant foods. All five students involved — Williams, Shoulderblade, Virginia Yelechchin, Ilene Goudy and Corey Edgar — are enrolled Yakama Nation members or descendents. “All my life, since I could walk, my mom took me huckleberry picking with her,” Williams said. Shoulderblade has visited the fields each year, starting in high school. “It was really cool, putting together my science world and my cultural identity,” he said. 

Kyle Shoulderblade at the Yakama Nation Wildlife Program points to the wing of one of the fruit flies viewed under the microscope. Carol Craig/Yakama Nation Review

The term “researcher” can have negative connotations in tribal communities, said Victoria Walsey, teaching faculty at Northwest Indian College, who helped lead the study. Over the decades, non-Native anthropologists and scientists have too often parachuted into tribal communities to extract culturally sensitive information. 

“It’s a different perspective when you’re talking about studying a berry as a resource versus studying a berry as a relative,” said Walsey, an enrolled member of the Yakama Nation and descendent of the Confederated Tribes of the Warm Springs. “All of the students had connections or had experience with either going to a feast or were berry pickers themselves, or had some understanding of how significant that berry is to the Yakama people — as a sister and not just as a resource for ice cream or milkshakes.”