Researchers at the University of California, Riverside, have created a machine learning-based method to identify chemical compounds that can safely repel honey bees from pesticide-treated crops. This development could help address the ongoing decline in honey bee populations, which has been partly linked to pesticide exposure. The study, published in the journal eLife, was led by Anandasankar Ray, a professor of molecular, cell, and systems biology, and involved collaboration with honey bee researchers from the lab of Boris Baer, a professor of entomology. The team focused on the honey bee's complex olfactory system, which includes over 200 odor receptors that allow the insects to detect a wide range of volatile compounds. To better understand how bees respond to different scents, the researchers used a machine learning model trained on the chemical structures of odorants and previously recorded behavioral responses of bees. They improved the model by incorporating new behavioral data from both honey bees and Drosophila (fruit flies), which helped increase the accuracy of predictions about insect olfactory responses. Once optimized, the system analyzed over 50 million compounds and identified approximately 130 with strong potential as bee repellents. Field tests confirmed that the most promising candidates effectively repelled bees from honeycombs without causing harm. This research could lead to the development of pesticide formulations that protect pollinators like bees while still meeting the needs of modern agriculture. The bee-repelling compounds also have other practical applications, such as reducing the formation of beehives in public spaces like hospitals, office buildings, and residential areas. They could also be useful in agricultural practices where pollination is not desired, such as in the cultivation of seedless fruits. Ray emphasized that the study shows how machine learning can be applied to real-world ecological challenges, helping to keep bees away from harmful pesticides without compromising crop protection. The research was conducted by Ray, Baer, and several other collaborators, including Joel Kowalewski, Barbara Baer-Imhoof, Tom Guda, Matthew Luy, and Payton DePalma. Ray is the founder and president of Sensorygen and Remote Epigenetics and holds equity in both companies. Kowalewski also has equity in Sensorygen. Ray, Kowalewski, Baer-Imhoof, Guda, Luy, and Baer are listed as inventors on a patent application related to the compounds discussed in the study.