This insect uses a protein to go green

Being green is a matter of life or death for Tettigonia cantans. Also known as upland green bush crickets, these insects’ green hue lets them hide from predators in the fens, marshes, mountain meadows, and potato fields where they live—over a region that extends from the Pyrenees to China. Researchers have now discovered that the bush crickets’ green camouflage arises from a protein that simultaneously binds both yellow chromophores and blue chromophores. This is the first time scientists have identified a single protein containing two distinctly colored molecules as the source of green coloration in a critter (Proc. Natl. Acad. Sci. U.S.A. 2025, DOI: 10.1073/pnas.2502567122).The finding represents an advance in fundamental science, says Nikolai N. Sluchanko of the Federal Research Center of Biotechnology of the Russian Academy of Sciences, who led the research. But he notes that the discovery could have applications in protein science, protein-based nanodevices, or pest control. Scientists have debated the source of green insects’ color since the 1880s. Sluchanko and coworkers came to the problem through their work on proteins that transfer greasy carotenoids in water. Last year, they identified a carotenoid-carrying protein that gives locusts their yellow color (Commun. Biol. 2024, DOI: 10.1038/s42003-024-06149-x). They screened other insects for similar proteins, and graduate student Nikita A. Egorkin found that T. cantans uses a related protein, dubbed dibilinoxanthinin, to achieve a green hue. After extracting dibilinoxanthinin from 100 bush crickets, the researchers were able to visualize its structure using X-ray crystallography. Not only does it noncovalently bind