NATURAL HISTORY

SALT CREEK TIGER BEETLE } Cicindela nevadica lincolniana
FAMILY: Carabidae

DESCRIPTION: About half an inch long, the Salt Creek tiger beetle has a metallic brown to dark olive green back, with a dark metallic green underside.

HABITAT: This beetle inhabits areas that contain moist, barren salt flats; a natural water regime resulting in annual high flows in saline streams in the early spring and summer; and nonvegetated streambanks and mid-channel areas.

RANGE: The beetle is found in northern Lancaster County, Nebraska, at Arbor Lake and along the banks of Salt Creek and its tributaries and associated saline wetlands. Its historical range is believed to have included similar habitat in extreme southern Saunders County.

MIGRATION: This subspecies is nonmigratory.

BREEDING: After first emerging around June 1, adult Salt Creek tiger beetles mate and females lay eggs in sloping, muddy, saline soil. Populations peak about two weeks after the beetles' initial emergence.

LIFE CYCLE: Little is known about this beetle's life cycle. Upon hatching, larvae construct burrows, after which larvae will molt multiple times. The precise number of molts is unknown, but most other tiger beetles have three larval stages. The U.S. Fish and Wildlife Service estimates that the beetle has a two-year life cycle and spends 11 months of the year underground.

FEEDING: The Salt Creek tiger beetle preys on smaller arthropods by grasping them with its mandibles.

THREATS: This beetle is primarily threatened by habitat alteration and destruction from agricultural, commercial and residential development; alteration of its habitat for dams and reservoirs; water pollution; and livestock grazing. Other possible threats include artificial lighting, which is thought to draw females away from their breeding habitat and lead to fewer eggs laid; collection by amateur insect collectors; and predation. All these threats are magnified by the beetle's small population size and vulnerability to environmental changes.

POPULATION TREND: This beetle's population is in decline. Surveys counted only 194 adult Salt Creek tiger beetles in 2009, down from 263 in 2008 and 777 in 2000. From 1991 to 2005, the number of sites containing Salt Creek tiger beetles declined from six to three.


Photo courtesy U.S. Fish and Wildlife Service