The Salt Creek tiger beetle: Lincoln's special bug

North of Lincoln sits an array of scattered wetlands, unique because of how salty they are.

“They're pretty rare. There's some spots in Oklahoma, Kansas and the Dakotas, where they occur. This is the only place in Nebraska,” said Ted LaGrange, Nebraska Game and Parks wetland program manager.

These wetlands also house a unique and rare kind of beetle: the Salt Creek tiger beetle.

LaGrange offers a tour of Frank Shoemaker Marsh, one of the few saline wetlands in Nebraska. The unique combination of salt and moisture is very conducive for specialized plants, as well as the endangered salt creek tiger beetle.

“Here's some sea blite, or suaeda, it is very much a saline plant, and you can actually take a nibble, and it's a little bit salty,” LaGrange said while bringing a small bit up to his mouth.” You can taste that salt in the sea blite, and so you're getting into a really saline part of the wetland here."

Plants like foxtail barley, spearscale and the endangered saltwort plant littered the white, dust-covered earth.

The salty wetlands are thought to have come about due to old salt deposits and water mixing and then being forced up out of the ground due to high underground pressure.

“It reaches the hyper saline, so it's the, basically, almost the salinity that you'd have in seawater,” LaGrange said. “And it rises to the surface here and then as that water evaporates away, it forms a salty crust. And that's what forms the saline wetlands here around Lincoln.”

LaGrange said that before Lincoln was settled, it's estimated there were around 20,000 acres of saline wetlands, but only about 2,000-4,000 acres remain due to the city’s growth. Losing almost 90% of their livable habitat has severely hurt the Salt Creek tiger beetle.

According to LaGrange, the channelizing of streams like Salt Creek for flood prevention led to the drying up of saline wetlands and the decline of Salt Creek tiger beetles.

“The city of Lincoln is actually where it's at because of saline wetlands, and so it was established as a salt mining community. Back in the mid to late 1800s salt was a really, really rare commodity and really important,” LaGrange said. “But when cheaper sources of salt were found underground in places like Oklahoma and Kansas, the price fell for salt, and it was no longer economically viable to scrape it off the surface of these wetlands, and so the city then just kind of grew out over some of these wetlands.”

The Salt Creek tiger beetle was greatly impacted by the loss of saline wetlands and has been considered critically endangered by the state of Nebraska and the U.S. government for some time. Experts estimate the wild population is between 250 and 800, which for an insect population is quite small -- even for an insect that only exists in the small wetlands north of Lincoln.

In 2011, U.S. Fish and Wildlife and Nebraska Game and Parks partnered with Omaha’s Henry Doorly Zoo and Aquarium, as well as the zoos in Lincoln and Topeka, Kansas, to start a program to breed Salt Creek tiger beetles and raise larvae, which are then released in the late spring and early summer.

“So this is a program that the zoo has been involved with since 2011 and U.S. Fish and Wildlife and Nebraska game and parks reached out to us because of our expertise in raising insects,” said Sarah Jenkins, supervisor of terrestrial invertebrates at Henry Doorly. “They wanted us to help with the captive breeding so that we can kind of do a head start program.”

The way Jenkins and her crew do this is by having a breeding population of beetles to create the next year’s planned release. The egg laying begins in June, usually hatching within 12 days. The larvae, according to Jenkins, are no bigger than a grain of white rice. She then fishes each larvae out of the larger enclosure and separates them into their own container to prevent them from eating each other. The larvae will then live in that container until they are ready to be released, normally taking only about one year in captivity to become ready to release. In the wild, the Salt Creek tiger beetle larvae takes around two years, primarily due to food being harder to find.

“Our goal for this year is 400 larva that we want,” said Jenkins. "We want more than that, we just can only handle between all the partners caring for 400 so we're going to have 400 that live here, and in Lincoln, and in Topeka, and then we want the rest out in the habitat doing the wild thing.”

Shaun Dunn, Natural Heritage Program zoologist for Nebraska Game Parks, is another person trying to bring the beetle back from the brink of extinction.

“The Salt Creek tiger beetle is just one of those hundreds of thousands of types of beetles out there, and it's one that happened to evolve with the saline wetlands that you can find only here, right around Lincoln, Nebraska,” Dunn said. “And it's a very unique tiger beetle because of that.”

Dunn was at Frank Shoemaker Marsh recently counting the Salt Creek tiger beetles, slowly walking around with his eyes to the ground.

“You can see these little mud flats that are kind of sticking out…and those are perfect habitat for Salt Creek tiger beetles and other tiger beetles…especially this kind of long one here," Dunn said.

The area along the Little Salt Creek Dunn is counting in was modified to be a better habitat for the beetles. The earth has been moved in such a way that it allows for these mud flats to develop. The mud flats are the perfect combination of saltiness and moisture for the beetles to lay their eggs, and for the larvae to live.

“So 35 [Salt Creek tiger beetles] right there. That's fantastic,” Dunn said. “A lot of people are always wondering, like, it's just a bug, like, why do we care about it? But it's, to me, it's all the stuff that comes with that bug, right? Like we get funding to help the Salt Creek tiger beetle, but with that funding, we're creating habitat for dozens of other species.”

The Salt Creek tiger beetle is a good indicator of the saline wetland’s health, Dunn said. If they are present, the salt-to-moisture ratio of the wetland is good.

The beetle helps the wetlands, which in turn helps the people living around them, LaGrange said.

“The benefits that saline wetlands and wetlands in general, provide are quite broad,” LaGrange said. “They're really important spots for wildlife diversity, plant and wildlife diversity…Wetlands, including saline wetlands, are also really important for other benefits to society, so things like recharging the groundwater in places,” he said. “Flood protection, so water that gets stored in a wetland or floods, you know, from these streams, when we have a high-water event, the water that goes out in these conserved areas is stored there and doesn't cause damage further downstream. And wetlands are also amazing filters of water, so pollutants that are being carried along in like the stream or overland runoff, as it passes through a wetland, it actually comes out cleaner.”

It is too early to determine if the population of Salt Creek tiger beetles is increasing, but as their livable range increases, the hope from people like Dunn is that the population will increase as well.