New Whirligig Beetle Showcases U.S. Biodiversity Hotspot

Males of the species *D. shorti* (shown here) measure 10.7-12.3 mm long and 6.2-7.0 mm wide. Females are slightly smaller. Some of the distinguishing features that set *D. shorti* apart from the similar but much more common *D. discolor* are a differently shaped protarsus (“front hand”), which he presumably uses to grasp the female during mating, and a differently proportioned aedeagus (reproductive organ).

By Leslie Mertz

Back in April, University of New Mexico Ph.D. candidate Grey Gustafson was on the hunt for a particular species of whirligig beetle in Alabama’s Conecuh National Forest, but something else caught his eye. He saw a few dozen other whirligig beetles making their spinning circles across the surface of a river, and noticed that they looked slightly different from the others he’d seen. So he collected a few samples and even took video of them in the wild with the intention of giving them a closer in the future. A couple of months later, he headed over to Enns Entomology Museum at the University of Missouri on an invitation from museum director Dr. Robert Sites.

“Dr. Sites noticed that in the museum’s collection there were 11 specimens of a whirligig beetle collected back in the 1970s and identified by somebody — they don’t know who — as possibly being a new species,” Gustafson said. “He contacted me because he knew I was working on a paper to help people identify the North American whirligig beetle species in the genus Dineutus.”

Gustafson not only confirmed that the 11 specimens were members of a new species, but he also got to thinking that they looked very much like those odd whirligig beetles he had collected in April. In fact, the 11 specimens were collected from the same habitat and general area where he saw the odd-looking whirligigs.

“When I got back and checked my samples, sure enough, it was the same species,” he said. “It was lucky that somebody had originally noticed that this was potentially new, and that the natural history collection was around to preserve the specimens and that Dr. Sites contacted me. And then it was even more serendipitous that I happened to stumble upon it when I was looking for Spanglerogyrus.”

As it turns out, this beetle is the first unequivocally new species of the whirligig family (Gyrinidae) to be described in the United States since 1991. Gustafson named it Dineutus shorti after University of Kansas coleopterist Dr. Andrew E. Z. Short.

“I volunteered as an undergrad in his lab, and he inspired me and showed me that you can have a career being an insect taxonomist,” said Gustafson, who is now finishing his doctorate. “He’s also incredibly passionate about aquatic beetles and biodiversity and conservation, and he’s really keeping the legacy of insect taxonomy alive and placing an emphasis on natural history collections. It was my honor to name it after him.”

D. shorti is important for a couple of reasons, Gustafson said. For one thing, its distribution is very small. While he found the common D. discolor species of whirligig beetle in many areas of the Conecuh National Forest, he saw D. shorti only in a short stretch of a creek, only within an old stand of long-leaf pine trees, and only in an area where D. discolor was not present. Secondly, this is a valuable habitat. As he noted in the Annals of the Entomological Society of America paper announcing the new species, the surrounding area, known as the southeastern coastal plain, is a relatively unrecognized biodiversity hotspot in the United States, and is in need of both designation as a globally significant ecosystem and further exploration by entomologists.

While on this collecting trip to Alabama, Grey Gustafson found specimens of a new species of whirligig beetle. The species, *Dineutus shorti*, is the first unequivocally new U. S. whirligig beetle to be named in nearly a quarter century. Photo courtesy of Grey Gustafson.

“Unfortunately, it is really hard to find information on this region for freshwater invertebrates, aside from snails, mussels, and caddisflies. Beyond those groups, we haven’t really sampled for freshwater invertebrates,” he said.

Although D. shorti is the fifth insect that Gustafson has named, finding a new species still gets his heart pumping.

“It’s hard to describe the thrill I felt when I was looking at these old specimens from the 1970s and realizing, wow, this is actually something new, and not only is it new, but it’s right here in the United States,” he said. “And then I actually found it myself! It’s not like this species was small or cryptic. If you look at the video, you can see they’re about 10 mm in length and hanging out on the surface of the water, so if you just walk up to the river, there they are. It’s really exciting.”

Once he completes his doctorate, Gustafson plans to take an offer to go to Stockholm, where he will work with a colleague who is conducting surveys in Madagascar. In just the past year, Gustafson has traveled to Australia, Thailand, Madagascar, Panama, and the United States as part of his studies.

“My dream job is to become a tenure-track professor working on insect systematics and using phylogenetics to answer interesting questions,” he said.

Leslie Mertz, PhD, teaches summer field-biology courses, writes about science, and runs an educational insect-identification website, www.knowyourinsects.org. She resides in northern Michigan.