Plate Nº 18 · recorded October 10, 2026
Biology & EvolutionReported finding
Yeast Identified in Rutgers Lab Repels Invasive Blueberry Pest
Rutgers researchers identified a yeast, Pichia occidentalis, that repels spotted-wing drosophila—an invasive pest threatening $94 million worth of New Jersey blueberries. The discovery started as an accidental kitchen invasion.
By James Calloway3 min read687 words
In brief
- The yeast Pichia occidentalis was found to repel spotted-wing drosophila and reduce its egg-laying in lab tests, per a 2026 paper in Applied and Environmental Microbiology.
- Spotted-wing drosophila was first detected in New Jersey in 2011.
- New Jersey growers harvested 47.5 million pounds (21.5 million kg) of blueberries in 2025, worth more than $94 million.
- Lead author Beth Ferguson and colleagues at Rutgers' Philip E. Marucci Center identified the compound after D. melanogaster flies invaded lab colonies from a nearby kitchen.
- DOI: 10.1128/aem.01135-26
A yeast that naturally repels the spotted-wing drosophila, one of the costliest pests threatening U.S. berry production, emerged from an accidental invasion of a Rutgers laboratory kitchen. The compound, described in a paper published in 2026 in Applied and Environmental Microbiology, could point toward nonchemical alternatives for fruit growers.
The yeast, Pichia occidentalis, "elicited aversive responses" in spotted-wing flies and sharply cut their egg-laying, while remaining attractive to common fruit flies (Drosophila melanogaster). Lead author Beth Ferguson, a postdoctoral researcher at Rutgers' Philip E. Marucci Center for Blueberry and Cranberry Research, called the chain of events "a very happy accident."
How did a kitchen accident lead to a discovery?
Each summer, Ferguson's team breeds colonies of spotted-wing drosophila at the Marucci Center to test nonchemical pest-control strategies. For more than a decade, an unexpected rival kept showing up: D. melanogaster, the common fruit fly, slipping in from a kitchen near the colony room.
The invaders fed on rotting food scraps in the kitchen and overwhelmed the spotted-wing colonies, triggering visible die-offs. With thousands of flies packed into the enclosures, researchers could not sort them by eye. They detected the takeover by smell.
"We'd notice a smell change, going from a spotted-wing smell—like cornmeal—to a very heavy vinegar decay odor, which is the telltale smell of melanogaster," Ferguson said.
What makes this pest so hard to control?
Spotted-wing drosophila, first detected in New Jersey in 2011, behaves differently from typical fruit flies. Rather than laying eggs in already rotting produce, the female uses a sawlike structure called an ovipositor to drill into intact, ripening fruit. Larvae hatch and feed inside the berry from within.
The species ranks among the most damaging threats to soft-fleshed fruit in the United States. In 2025, New Jersey growers harvested 47.5 million pounds (21.5 million kilograms) of blueberries, worth more than $94 million, a figure that places the state among the nation's top producers. Blueberries remain the state's No. 1 crop.
Conventional control leans on chemical insecticides that do not always provide full protection and can harm bees and other beneficial insects.
What did the lab tests reveal?
As the vinegar smell intensified, Ferguson noticed a filmlike deposit on the flies' food. She swabbed it and identified the culprit: a yeast deposited by the invading D. melanogaster. She then partnered with USDA researcher James Polashock to identify the species and with Rutgers-New Brunswick biochemist Jennifer S. Sun to confirm what it did to the pest.
Sun and undergraduate researcher Tia Hart ran a series of behavioral assays.
"Our first question was whether this is truly repulsive to spotted-wing," Sun said. "The answer came quick."
In choice tests, spotted-wing flies avoided surfaces dosed with P. occidentalis volatiles. The same compound kept drawing D. melanogaster, hinting that the two species read the yeast in opposite ways—as a territorial marker for one species and a warning sign for the other. Spotted-wing flies exposed to the yeast also laid far fewer eggs afterward.
What happens next?
The compound could eventually feed into a low-toxicity tool that protects berries while leaving beneficial insects largely intact. But Ferguson warned that moving from a lab result to a registered pest-control product typically takes years. Field trials lie ahead to test whether the compound works in real orchards and how it interacts with weather, native fungi, and existing pest-management programs.
For Sun, the study has already shaped how she teaches.
"I've been using it as a model for my students, explaining that when an experiment yields unexpected results, they shouldn't assume that they did something wrong," she said. "Instead, they could ask why it's happening and if there's another phenomenon we could be studying. When the scientific process is used in experimentation, the result could be a very fruitful project like this one."
The paper, Pichia occidentalis volatiles elicit divergent behavioral responses in Drosophila suzukii and Drosophila melanogaster, appeared in Applied and Environmental Microbiology. DOI: 10.1128/aem.01135-26.
via Phys.org Biology (Source)
More from James Calloway
Show full bio
Staff writer covering marketplaces and e-commerce at SciBeat.
205 articles
Nearby plates
- Flesh-eating screwworm resurfaces in Texas and New Mexico
- Insects Keep Vertebrates Alive as Food, Medicine and Home Builders
- MIT Engineers Bacteria Into Living Transistors for Biological Circuits
- Scientists Find a Way to Kill a Drug-Resistant Deadly Fungus
- First U.S. Clone of Tomato Spotted Wilt Virus Built in Texas