UNIVERSITY PARK, Pa. — Twenty-two new species of gall wasps have been identified and named for the first time, thanks to new research led by a Penn State College of Agricultural Sciences graduate student.
The study, which includes the new names and descriptions of each species along with an identification guide, recently was published in the journal Zootaxa and nearly doubles the number of known species in this genus of wasps.
The tiny wasps — which live in small structures called galls that they steal from other wasps — were named after famous thieves and tricksters in history, mythology and pop culture, the researchers said.
For example, they named one wasp after Prometheus, a titan in Greek mythology who stole fire from the gods and brought it to humanity. The researchers said they felt that the wasp's fiery red coloring made it a natural fit for the name.
Louis Nastasi, doctoral student of entomology at Penn State and lead author on the paper, said now that the species have been properly identified, it opens the door for more research on the wasps, which are relatively understudied.
"By naming these species, we give other researchers an anchor they can carry forward to other studies because now they can identify wasps that were previously unknown," he said. "It provides a base and a tool kit for future work that could help us understand these species and their ecosystems more broadly."
The research stemmed from a separate study by another team — which also co-authored the current study — focused on the evolution of gall wasps. Despite having DNA data from multiple wasps, the researchers were unable to pinpoint which species they were actually dealing with. The team, which has had a long-standing collaboration with Nastasi, re-connected with him at the International Plant Gall Symposium, spurring a discussion about the mystery.
"I ended up in conversation with Andrew Forbes, who's the leader of the University of Iowa team, and he told me about the difficulties they were having," Nastasi said. "And since my area of expertise is species identification, description and diagnosis of these tiny wasps, he asked if it would be possible for me to get involved and figure out what exactly is going on."
Upon receiving the wasp samples, Nastasi said he realized that the reason the other researchers were having a difficult time identifying them was because those particular species had never been officially discovered and named.
To begin, Nastasi combined biological and molecular information on the species from the team's previous study with his own morphological analysis, which looks at the anatomy and physical characteristics of the insects.
Nastasi said it was essential to use each of these three types of data, as having just molecular data or just looking at the insects' physical appearance would not be enough to properly separate one species from another.
"We found that some of the insects thought to be one single species were actually two independent species, and that using only the molecular data did not sufficiently separate them into multiple species," he said. "We had to combine that information with this new morphological analysis, and then by combining those types of data, it allowed us to get a clear vision of what each of these species are."
Once the wasps were properly categorized into species, Nastasi said it was time to assign them names.
One wasp was named Ceroptres selinae — inspired by Selina Kyle, better known as Catwoman from DC Comics. Another was named Ceroptres bruti, after Marcus Junius Brutus — the Roman politician who infamously betrayed Julius Caesar. A third was named Ceroptres soloi — after Hans Solo, a smuggler and thief portrayed by Harrison Ford in the Stars Wars movies.
"We tried to get a little more personal than just matching a list of names to a list of species," Nastasi said. "It's definitely fun to hypothesize why a name is suited to a certain species. A lot of effort goes into identifying these species and there's a lot of art in choosing a good species name, so it was exciting to exemplify that and really carefully select names for these new species."
The study is just the beginning of understanding this group of wasps, which is going to take a lot more research to unlock, Nastasi said. While many other unknown species of gall wasps have been collected, many are waiting in drawers in museums for someone to begin the identification process.
Additionally, little is known about the biology of these wasps, he added, so future studies could focus on furthering knowledge about their life cycle, for example.
"We know they live in these galls, we know which galls they live in, but there's still so much we don't know," Nastasi said. "For instance, how do they actually use the contents of the gall to feed themselves? It's going to be interesting to see how our new species inform both future species discovery studies and research on the wasps themselves."
Contributing to the research were Cecil Smith, Charles Davis and Andrew Deans, Frost Entomological Museum, Penn State; Anna Ward, Guerin Brown and Andrew Forbes, University of Iowa; Y. Miles Zhang, University of Edinburgh; Chris Friesen, Manitoba Conservation Data Centre; and Shannon Rollins and Carly Tribull, Farmingdale State College.
The U.S. National Science Foundation, Society for Systematic Biologists, Erickson Discovery Grant at Penn State, Center for Global and Regional Environmental Research and University of Iowa helped support this research.
