Another new species of wasp discovered by researchers

A newly identified species of wasp, Chrysonotomyia susbelli, has been discovered in Houston, Texas, marking the 18th new species identified by Rice University’s Scott Egan and his research team since 2014. The discovery, the fourth wasp species found on the university’s grounds in seven years, reveals the hidden world of parasitoid wasps and the complex ecosystems that thrive outside our doors.

Chrysonotomyia susbelli is a parasitoid wasp about 1 millimeter long that emerges from galls, or tumor-like growths created by the gall wasp Neuroterus bussae found on the leaves of southern live oaks. The galls serve as microhabitats in which the larvae feed, develop, and pupate. The research team’s study was published in the journal Zoo Keys September 18th.

“Chrysonotomyia susbelli represents the sixth species of its genus described in North America and the first globally known to parasitize cynipid wasps,” said Egan, associate professor of ecology and evolutionary biology.

The wasp was discovered and named by Brendan O’Loughlin, a senior at Rice and first author of the study. “The wasp’s goldenrod color is almost identical to the official colors of Wiess College, my residential college,” O’Loughlin said.

To confirm the uniqueness of the species, the research team conducted genetic analysis and a detailed study of the wasp’s physical characteristics under a microscope. Their investigation also included reviewing historical literature to ensure the species had not been previously described.

This research was supplemented by DNA barcoding data and observations of the wasp’s natural history, including host associations and unique leaf-scanning behavior exhibited by female wasps. The researchers also modified the identification key for members of the New World, groups of species found exclusively in the Americas, to include this new species.

Egan stressed the importance of studying local biodiversity. “You don’t have to go to a remote rainforest to find new and beautiful things; you just have to go out and observe,” he said.

This discovery reveals a previously unexplored ecological niche involving Chrysonotomyia parasitoids, cynipid wasps and oaks, suggesting that there may be many other undiscovered species in this system.

“Generations of Chrysonotomyia susbelli have likely lived unnoticed on Rice University oaks since its founding,” Egan said.

Co-authors of the study include Pedro F.P. Brandão-Dias, a PhD in ecology and evolutionary biology from Rice and current postdoctoral fellow at the University of Washington, and Michael Gates, a parasitoid wasp specialist in the U.S. Department of Agriculture’s Systematic Entomology Laboratory at the Smithsonian National Museum of Natural History.