A bright pink insect might seem easy to spot in a green rainforest. But in Panama, researchers watched one pink katydid turn completely green over 11 days. They wondered whether its changing color might help it blend in with tropical leaves as they change color too.
The insect, Arota festae, is a katydid also known as a "bush cricket." Native to Panama, Colombia, and Suriname, it is about one inch long. It is usually light green, with broad, rounded front wings that resemble young leaves. That likeness helps it blend in with the plants around it.
Bright pink katydids have been reported before. In a few other species, researchers have attributed the pink color to erythrism, a genetic condition that causes a lasting excess of red pigment. A bright pink insect was thought to stand out to predators. But in this case, the pink faded, raising the possibility that it could serve a purpose under certain conditions.
In a study published in Ecology in March 2026, researchers describe how they found the unusual katydid at the Smithsonian Tropical Research Institute's field station on Barro Colorado Island in Panama. They spotted the female on March 27, 2025, at 11:12 p.m., under a station light just a few meters from the rainforest.
The team kept her in a cage with other katydids of the same species, which were the usual green. The researchers provided a mix of green plants, apple, and water. They also collected fresh greenery from nearby to put in the cage and replaced it every two days.
After four days in captivity, her bright pink faded to a lighter shade. The team began photographing her every 24 hours. Seven days later, on April 7, she was completely green and looked like her green cage mates. She stayed green for the rest of the observation period. The team also found another katydid of the same species with markings that resembled a decaying leaf, a pattern that had not been reported in this species before.
Tropical katydids can resemble leaves in color, shape, texture, vein patterns, and even the way they hold themselves. Chameleons and octopuses are familiar examples of animals that can change color quickly. This katydid changed much more slowly, yet the shift happened within a single stage of its life. The researchers think the insect may have gradually lost, gained, or altered pigments. They do not know what started the change, although its diet or the color of the leaves in the cage could have played a part.
One possible explanation for the pink color is that it helps the katydid resemble the young leaves of some tropical plants. These leaves contain little chlorophyll, the green pigment in plants, when they first appear. They can look red or pink before turning green as they mature, a process known as "delayed greening." The young leaves are often less nutritious and less appealing to animals that eat plants. On Barro Colorado Island, they can be found year-round.
Previous studies have found that Arota festae feeds on plants that show delayed greening. The researchers suggest the katydid might hide near pink leaves and move a short distance to feed or rest on nearby green leaves, which tend to be more nutritious. As the young leaves turn green, a katydid that changes color could keep matching its surroundings.
So far, the researchers have documented the full change in one katydid in a cage. They would need to study the insects in the wild to see whether pink coloration helps them avoid predators and whether the gradual shift to green gives them an advantage as the leaves mature.