06-05-2025
‘Rainbow' creature — that lives inside crickets — found as new species in China
World 'Rainbow' creature — that lives inside crickets — found as new species in China
In a karst cave in China, a rainbow-like parasitic creature was discovered as a new species.
Francesco Ungaro via Unsplash
Relationships between living things can take many forms.
Bees get nectar from flowers while acting as pollinators in a process called mutualism. Whales are covered in barnacles that don't hurt the massive animals but allow the barnacles to feed, a commensal relationship.
But sometimes, like a tick on a dog, one animal takes advantage of another — a parasite.
More than a decade ago, a professor in China exploring a karst cave discovered five small white horsehair worms, a parasitic animal, but lost the specimens, according to a study published May 5 in the peer-reviewed journal Zoosystematics and Evolution.
It would be another five years before the worms were found again in 2019, this time collected and their genetics analyzed, according to the study.
'During the fieldwork, we focused on examining water pits and their surroundings inside caves, carefully turning over stones,' researchers said. 'All living worms were placed in water bottles filled with a small amount of water and transported back to the laboratory for further study. The worms were placed in a dark box designed to simulate the cave environment, with the temperature maintained at approximately (60 degrees Fahrenheit).'
Some of the worms were found as 'free-living' animals, meaning they were on their own either in the water or hidden under the rocks, according to the study.
Free-living worms were found in the small puddles in the caves, researchers said. Zou Y-Z, Huang J, Xiang H-Y, Li S, Tang Y, Liu Z-X (2025)
Zoosystematics and Evolution
Others, however, were found inside another animal.
The worms emerged from the bodies of Tachycines, a group of cave-dwelling crickets, according to the study.
When researchers looked at the morphology, or physical attributes of the worms, and the phylogeny, or genetic history, they realized it was a species new to science.
Gordius wulingensis, or the Wuling Mountains horsehair worm, range in size from about 3.8 to 11.2 inches long for males and 5.7 to 29.3 inches for females, according to the study.
One end is 'columnar and spherical,' with a 'nearly transparent' white layer underneath the skin separating the internal structures from the outside, researchers said.
'All specimens exhibit a rainbow-like reflection on the skin, white body color, lacking of a dark-brown collar,' according to the study.
The worms are reflective with a rainbow-like coloration, researchers said. Zou Y-Z, Huang J, Xiang H-Y, Li S, Tang Y, Liu Z-X (2025)
Zoosystematics and Evolution
The worms were found in multiple karstic caves in the Wuling Mountain area, a region in Hunan, China, according to the study.
'This species is usually observed in puddles, beneath stones, or sometimes on the moist soil of the caves,' researchers said. 'Occasionally, they are found on the cave walls at elevations exceeding (3.2 feet) above ground level.'
Horsehair worms, also called Gordian worms, develop in the bodies of grasshoppers, crickets, cockroaches and some beetle species, according to the University of Kentucky. They do not infect humans, livestock or pets, and are considered harmless.
The worms also live inside the cave's crickets, researchers said. Zou Y-Z, Huang J, Xiang H-Y, Li S, Tang Y, Liu Z-X (2025)
Zoosystematics and Evolution
Hunan is an inland province in southeastern China.
The research team includes Ya-Zhen Zou, Jie Huang, Hai-Yang Xiang, Shi Li, Yan Tang and Zhi-Xiao Liu.
Irene Wright
McClatchy DC Email this person
Irene Wright is a McClatchy Real-Time reporter. She earned a B.A. in ecology and an M.A. in health and medical journalism from the University of Georgia and is now based in Atlanta. Irene previously worked as a business reporter at The Dallas Morning News.
