Salt Creek tiger beetle facts for kids

Quick facts for kids Salt Creek tiger beetle
Conservation status
Endangered (ESA)
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Coleoptera
Family:	Carabidae
Genus:	Cicindela
Species:	C. nevadica
Subspecies:	C. n. lincolniana
Trinomial name
Cicindela nevadica lincolniana (T. L. Casey, 1916)

The Salt Creek tiger beetle (Cicindela nevadica lincolniana) is a very rare and endangered type of tiger beetle. It lives only in the salty wetlands of northern Lancaster County, Nebraska, close to the city of Lincoln, Nebraska. This beetle is a fast hunter, using its strong mouthparts called mandibles to catch other insects.

It is one of the rarest insects in North America. In 2009, only 194 adult beetles were found, which was fewer than the 263 found in 2008, and much less than the 777 found in 2000. However, people are working hard to help the population grow. In 2013, there were 365 beetles, which is one for every day of the year! Adult beetles can move super fast to catch their food.

The Salt Creek tiger beetle looks different from other tiger beetles. It has a special body shape and color pattern. These beetles also have ways to stay cool in hot weather, which helps them survive. They have also learned to live in tough, salty places. Sadly, this species is endangered because people have destroyed its home and used chemicals called pesticides. To help them, scientists are trying to create new homes for their young.

What Makes This Beetle Special?

There are many differences between the Salt Creek tiger beetle (C. n. lincolniana) and other types of tiger beetles. These differences come from how they have changed over a very long time. For example, the Salt Creek tiger beetle adults are most active about a month earlier than another type, C. n. knausi. They also like wetter places.

For thousands of years, since the Ice Age, Salt Creek tiger beetles have been separated from other tiger beetle groups. This separation caused them to develop unique traits. These changes led to the differences we see today in how many beetles live in an area and how they behave.

How to Describe the Salt Creek Tiger Beetle

The Salt Creek tiger beetle is about 12 millimeters (0.5 inches) long. It has a shiny brown to dark olive-green color on top. Its belly is a dark metallic green. Its body shape and color pattern are unique compared to other tiger beetle types.

Male and female adult beetles look a bit different. Males have short white hairs on the inside of their front legs. Females do not have these hairs. This super-fast beetle can run up to 5 miles per hour!

The salty wetlands of the Little Salt Creek Tributary in Lincoln, Nebraska, are home to these beetles.

Where Do They Live?

Salt Creek tiger beetles (C. n. lincolniana) live only along the banks of the Salt Creek and its smaller streams. They also live in the muddy areas of salty marshes in northern Lancaster County, Nebraska. You can also find them near Arbor Lake. Studies have shown that this beetle is very rare in these eastern Nebraska salt marsh areas.

What Is Their Home Like?

Adult Salt Creek tiger beetles prefer wet, muddy conditions in Nebraska's salty wetlands. Other tiger beetle types often like drier, flatter areas. C. n. lincolniana are usually found right next to the water's edge and in shallow water.

What Do They Eat?

Salt Creek tiger beetles eat other insects. When they are young (larvae), they stay in their burrows. They wait for small insects to come close, then pull them into the burrow to eat. Adult beetles walk around and hunt for bigger insects. They use their excellent eyesight to find prey and can move very quickly to catch it.

Life Cycle of the Salt Creek Tiger Beetle

Scientists are still learning about the full life cycle of the Salt Creek tiger beetle. Their life usually lasts 1 to 2 years. Adult beetles appear in early June and stay active until mid-July. After they mate, the females lay their eggs in soil that has the right amount of salt. A female can lay about 50 to 200 eggs.

After 10 to 14 days, the eggs hatch. The young beetle, called a larva, digs a long, tube-shaped burrow up to 1 meter deep. The larva is a very hungry eater. It catches any prey that comes too close to its burrow. This species grows through three larval stages, called instars. Each stage has a larger burrow opening.

As the weather gets warmer, the larvae get ready to change into adults. This process is called pupation. The larva digs a side room in its burrow and closes the entrance. Then, in June, the new adult beetles emerge from their pupal cases, and the cycle starts all over again.

How Do They Lay Eggs?

Female Salt Creek tiger beetles lay their eggs on the soil surface at night. Other related species, like Cicindela fulgida, lay their eggs underground. Salt Creek tiger beetles prefer salty soil because the salt helps them lay eggs. This means the salt content affects where the larvae will dig their burrows.

The places females choose to lay eggs are very important. This is because the larvae depend on these specific burrows to catch prey. Since the Salt Creek tiger beetle's home is already very small, it's even more important for females to pick the best spots. They consider many things, like location, how easy it is to get to, and how salty the soil is.

How Do They Share Space?

The salty wetlands of eastern Nebraska are home to many different types of tiger beetles that live together. This means they often compete for the same food and space. To avoid too much fighting, these species have developed ways to share resources, which is called niche partitioning.

One way they do this is by controlling their body temperature (thermoregulation). They avoid the sun when it's hottest, spend time in shallow water, and position their bodies away from the hot soil. These behaviors help reduce competition between the different beetle species. Research shows that Salt Creek tiger beetles, along with C. circumpicta and C. togata, all use egg-laying to share space, but they do it differently depending on the soil's saltiness. When females eat more, they can lay more eggs. Since many young beetles die, laying more eggs is a big advantage for the species.

Who Are Their Enemies?

Adult and larval Salt Creek tiger beetles hunt and eat other insects and small creatures. Adults also sometimes eat plant material. Larvae hide in their tunnels and attack prey that passes by. These beetles have excellent eyesight and react extremely fast.

Protecting the Salt Creek Tiger Beetle

People started paying attention to the Salt Creek tiger beetle in the mid-1980s. Studies by the University of Nebraska–Lincoln showed that the beetle was very rare. A detailed study began in 1991. Since then, the number of C. n. lincolniana has been counted every year. The population was lowest in 1993 with 115 beetles and highest in 2002 with 777 beetles.

In the 1990s, the beetle was added to the Nebraska endangered species list. Then, on October 6, 2005, the U.S. Fish and Wildlife Service officially listed it as an endangered species under the federal Endangered Species Act. From 1991 to 2005, the number of places where Salt Creek tiger beetles lived dropped from six to just three, covering only 35 acres.

On May 5, 2014, the U.S. Fish and Wildlife Service set aside 1,110 acres as critical habitat for the beetle. This became official on June 5, 2014. These protected areas include salty wetlands along Little Salt Creek, Rock Creek, Oak Creek, and Haines Branch Creek in Lancaster County. The goal is to have at least six healthy populations there. A similar plan to help the beetles recover was released in 2017. The U.S. Fish and Wildlife Service says they will change the beetle's status from endangered to threatened when there are between 500 and 1,000 beetles in each of three protected areas, along with other habitat goals.

The Omaha Henry Doorly Zoo and the Topeka Zoo are working together to save this species. The Omaha Zoo keeps the eggs until they hatch. Then, the young larvae are sent to the Topeka Zoo. Topeka raises the larvae for about a year. After that, they travel to Nebraska to be released as adults. This helps increase the number of adult beetles in the wild.

How Humans Affect Them

Losing Their Home

The Salt Creek tiger beetle population has shrunk a lot because people have destroyed their homes. This happens when salty marshes are drained for farms or buildings. Runoff from farms and the city of Lincoln also harms their habitat. Filling in wetlands and changing the path of creeks also cause problems.

Even though a few new places with these rare beetles have been found, their numbers are still low. The biggest population is at the Little Salt Creek. Straightening a part of the creek and covering it with rocks to control erosion also hurt the beetles. This reduced their habitat and caused their population to drop from 115 to just 54 beetles in 1991. Since then, some beetles have returned to the edges of the soil. But it is very important to protect the small amount of habitat they have left.

This species is at high risk of disappearing. Not only are the salty wetlands they live in getting smaller, but there are also very few wet spots within them. The Salt Creek tiger beetle has lost over 90% of its home. They also suffer from plants that don't belong there, cattle grazing, changes in water, and human activities. City lights can attract the beetles away from their homes, which increases their risk of dying. Also, if females are drawn away, they can't lay their eggs at night.

Population Decline from Pesticides

Using pesticides is another reason the Salt Creek tiger beetle population is shrinking. Scientists studied three common pesticides: glyphosate, bifenthrin, and imidacloprid. They tested them on a related species, Cicindela circumpicta, to avoid harming the already endangered Salt Creek tiger beetle.

These beetles can come into contact with pesticides from nearby farms through direct contact or contaminated water. Studies found that glyphosate was not harmful. However, C. circumpicta was very sensitive to both imidacloprid (a type of neonicotinoid) and bifenthrin (a type of pyrethroid). This suggests that using too much of these pesticides is likely a big reason for the decline of the endangered Salt Creek tiger beetle. That's why regular pesticide testing is needed to protect these beetle populations from harmful chemicals.

Protecting the Beetles

It's important to find different ways to protect this beetle population. Since they mostly live in the salty wetlands of the Little Salt Creek in Lancaster County, Nebraska, scientists are looking for the best soil type and saltiness to help them survive. Researchers found the best conditions to encourage females to lay eggs. This helps increase the number of larvae and adults. Studies in 2013 and 2014 showed that the type of soil made a big difference, but the level of saltiness did not.

Another way to help the population grow is by raising beetles in a lab and then releasing them into new or old habitats. Researchers filled containers with soil from the beetles' natural home. They put a pair of adult beetles in each container and controlled the temperature and humidity. Studies on the best soil type and saltiness helped make the breeding conditions even better. It was found that a mix of loess and sand was best for egg-laying. There was no difference between adding 0.5 M and 0.354 M salt solution. Females did not lay eggs on native soil alone, which suggests they prefer a loess/sand mix over native soil that has more clay. More studies are needed to understand why.

In 2011, many groups teamed up to breed these beetles and release them. These groups include the City of Lincoln, U.S. Fish and Wildlife Service, Lower Platte South Natural Resource District, Omaha's Henry Doorly Zoo, Nebraska Game and Parks Commission, Lincoln Children's Zoo, and the University of Nebraska. A main goal is to buy land and fix it up for the beetles. The Saline Wetlands Conservation Partnership has over 15 groups that buy wetlands, teach others, and work to save these lands. The City of Lincoln helps a lot with buying land, even creating salty mud flats along streams for the Salt Creek tiger beetle.

What's Next for the Beetles?

For the past 30 years, the number of places where these beetles live has been shrinking fast. However, new areas are being bought and managed to protect them. In the last ten years, the beetle population has been fairly stable. Researchers plan to release more beetles into recently restored salty wetlands. This will help them grow in new places where they weren't before. These releases will help scientists learn more and collect important information for this cause.

See also

• Platte River caddisfly