Researchers have identified a new species of wasp, Chrysonotomyia susbelli, in Houston, Texas. This marks the 18th new species discovered by Scott Egan and his team at Rice University since 2014. It’s also the fourth species of wasp found on the university campus in just seven years, highlighting the fascinating world of parasitoid wasps and the complex ecosystems right outside our doors.
Chrysonotomyia susbelli is a small parasitoid wasp, measuring about 1 millimeter in length. It emerges from galls—swellings on leaves caused by the gall wasp Neuroterus bussae, which affects southern live oaks. These galls act as microhabitats where the larvae feed, grow, and develop into adults. The findings of the research were published in the journal ZooKeys on September 18.
“Chrysonotomyia susbelli is the sixth species of its kind documented in North America and the first known globally to parasitize cynipid gall wasps,” explained Egan, who is an associate professor of ecology and evolutionary biology.
The discovery and naming of the wasp were carried out by Brendan O’Loughlin, a senior at Rice and the first author of the study. “The wasp’s goldenrod hue closely matches the colors of Wiess College, my residential college,” O’Loughlin noted.
To verify that this wasp was indeed a new species, the research team performed a genetic analysis and an in-depth examination of its physical characteristics under a microscope. They also reviewed historical literature to confirm that the species had not been previously documented.
This research included DNA barcode information and observations of the wasp’s natural behaviors, such as its unique leaf-scanning habits displayed by the females. Additionally, the researchers updated the identification key for New World species to include the new wasp.
Egan highlighted the significance of exploring local biodiversity. “You don’t need to journey to a far-off rainforest to discover new and intriguing life; often, you just need to look outside your door,” he stated.
The discovery suggests the existence of an uncharted ecological niche involving Chrysonotomyia parasitoids, cynipid gall wasps, and oaks, indicating that many more undiscovered species may be present within this ecosystem.
“For generations, Chrysonotomyia susbelli has likely been living unnoticed on the oaks of Rice University since the institution was established,” Egan remarked.
