The Salt Creek tiger beetle (''Cicindela nevadica lincolniana'') is a critically

endangered subspecies An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

tiger beetle Tiger beetles are a family of beetles, Cicindelidae, known for their aggressive predatory habits and running speed. The fastest known species of tiger beetle, ''Rivacindela hudsoni'', can run at a speed of , or about 125 body lengths per second. ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the saline

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

s of northern

Lancaster County, Nebraska Lancaster County is a county located in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 322,608, making it the second-most populous county in Nebraska. Its county seat is Lincoln, the state capital. The county ...

, adjacent to and immediately to the north of the city of

Lincoln Lincoln most commonly refers to: * Abraham Lincoln (1809–1865), the sixteenth president of the United States * Lincoln, England, cathedral city and county town of Lincolnshire, England * Lincoln, Nebraska, the capital of Nebraska, U.S. * Lincoln ...

. It is a predatory insect, using its mandibles to catch other insects. The beetle is one of the rarest insects in

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; surveys showed that 194 adults existed in 2009, down from 263 in 2008, and 777 in 2000. However, efforts are continuing to boost the population, which in 2013 numbered 365 beetles: one beetle for each day in a regular year.

Description

The Salt Creek tiger beetle measures about 12 mm (0.5 in.) in length. The beetle has a metallic brown to dark olive green coloration, with a dark metallic green underside. Its body form and color pattern differs from other tiger beetle subspecies.

Life cycle

Little is known about the life cycle of the Salt Creek tiger beetle. Adults emerge around June 1 and disappear five or six weeks later; populations peak about two weeks after the beetles' initial emergence. After mating, the beetles lay eggs in sloping, muddy, saline soil. Upon hatching, the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

constructs a burrow. The larva is a voracious feeder, capturing prey that wanders too close to the burrow. During the larval stage, the beetle will molt multiple times (the precise number is unknown, but most other tiger beetles have three larval stages). If a three-stage cycle does exist, it is likely that the Salt Creek tiger beetle spends over a year in the third larval stage. The larva prepares for its

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

tion by digging a side chamber and sealing the burrow entrance.

Habitat

The beetle is found at Arbor Lake, and along the banks of Salt Creek and its tributaries and in the mud flats of saline

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

es of northern Lancaster County. Its historical range is believed to have included similar habitat in extreme southern Saunders County. Much of this habitat has been degraded or destroyed by drainage of the salt marshes for agriculture or development and by runoff from surrounding farms and the city of Lincoln.

Conservation

Interest in the Salt Creek tiger beetle began with surveys conducted by the

University of Nebraska–Lincoln The University of Nebraska–Lincoln (Nebraska, NU, or UNL) is a public land-grant research university in Lincoln, Nebraska. Chartered in 1869 by the Nebraska Legislature as part of the Morrill Act of 1862, the school was known as the Universit ...

in the mid-1980s. These surveys indicated that the beetle was quite rare; an in-depth study of the beetle began in 1991. The beetle was added to the

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...

endangered species lists in the 1990s. On October 6, 2005, the

U.S. Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with oth ...

listed the beetle as an endangered species under the federal

Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...

. From 1991 to 2005, the number of sites containing Salt Creek tiger beetles declined from six to three, on 35 acres. On May 5, 2014, the U.S. Fish and Wildlife Service published its "final rule" on critical habitat for the beetle in the

Federal Register The ''Federal Register'' (FR or sometimes Fed. Reg.) is the official journal of the federal government of the United States that contains government agency rules, proposed rules, and public notices. It is published every weekday, except on feder ...

, designating 1,110 acres for conservation effective June 5, 2014. Established areas include saline wetlands along Little Salt Creek, Rock Creek, Oak Creek and Haines Branch Creek in Lancaster County, with a goal of supporting at least six populations. A similar recovery plan was published in 2017. The U.S. Fish and Wildlife Service has indicated they will downgrade its status from endangered to

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensat ...

once there are between 500 and 1,000 individuals in each of three protected zones, alongside additional habitat criteria.

References

External links