In Washington, the Columbia River tiger beetle is designated as a "Species of Greatest Conservation Need" due to their small number of isolated populations, highly limited distribution and range, and dependence on specialized, restricted and threatened habitats. This beetle may be extirpated.
Description and Range
The Columbia River tiger beetle is in the family Carabidae and subfamily Cicindelinae.
Ecology and life history
The Columbia River tiger beetle is a habitat specialist. This beetle uses well-established riverine sandbars and dunes along the Columbia and Snake River systems that are not inundated by spring floods or high water levels resulting from dam management. These sand habitats are open and only sparsely vegetated with shrubs and herbaceous species.
Carabids undergo complete metamorphosis, which means they have egg, larval, pupal, and adult life stages. These beetles typically reproduce annually; adults can live for several years, and larvae may require multiple years for complete development.
Females create shallow burrows in the soil with their ovipositor, where they lay eggs singly; larvae feed and develop, pupation occurs, and adults emerge from these tunnel-like burrows. Thus, soil condition, including texture, moisture, and temperature is a vital element of habitat quality.
Carabids are key predators of the insect world; as both larvae and adults they feed on other insects and, to a lesser extent, plant material. Adults hunt by sight and are fast runners that can quickly subdue their prey. Columbia River tiger beetle adults generally forage during the day, and at night burrow into soil, sand, or other substrate.
Adults tiger beetles can fly, but these species are highly localized and sedentary. They inhabit their sites year-round (as egg, larva, pupa and adult).
In Washington, the overall range of the Columbia River tiger beetle is southwest Washington, northeast Oregon, and Idaho: along the Columbia, Snake, and Salmon Rivers. Recent detections only have been in Idaho.
Carabid beetles have restricted ranges and distributions within Washington. Distribution is limited in part by a combination of their dependence on restricted ecological niches, and those niches’ location within rare habitat types. Their distribution and abundance is characterized by small numbers of isolated populations.
For a map showing range-wide conservation status and distribution of this species, check out NatureServe Explorer.
Sensitivity to climate change
The Columbia River tiger beetle occupies stable river sandbars and riparian sand dunes. They are likely sensitive to flooding, soil moisture, and temperature. Soil moisture and temperature may affect larval development, as larvae grow and molt in sand/soil burrows that draw moisture from adjacent rivers/streams. Flooding or prolonged inundation can cause larval mortality by washing away larval burrows and/or causing suffocation via submersion, although they can survive up to 3 weeks of inundation. Sandbars occupied by this species are typically large enough (extend >100m away from river) to avoid complete inundation during spring floods. Backwater flooding resulting from dam construction is thought to have extirpated all Washington populations.
Exposure to climate change
- Increased amount and/or duration of flooding
Conservation Threats and Actions Needed
- Energy development and distribution
- Threat: Requires narrow range of soil texture and moisture; threatened by inundation of reservoirs on Columbia/Snake Rivers.
- Action Needed: Where dams remain in rivers, develop timing and duration water level control best management practices to support species.
- Resource information collection needs
- Threat: Knowledge of current distribution is incomplete.
- Action Needed: Conduct baseline inventory on Snake River, and revisit historic locales and potential habitat on Columbia River.
See the Climate vulnerability section for information about the threats posed by climate change to this species.
Bartels, P. 1995. Columbia River tiger beetle 1995 survey: Columbia and Snake River, Region Two. Washington Department of Fish and Wildlife, Ephrata.
Labonte, J., D. Scott, J. McIver, and J. Hayes. 2001. Threatened, endangered, and sensitive insects in eastern Oregon and Washington forests and adjacent lands. Northwest Science, Vol. 75, Special Issue.
Shook, G. 1981. The status of Columbia River tiger beetle (Cicindela columbica Hatch) in Idaho (Coleoptera: Cicindelidae). Pan-Pacific Entomologist 57(2):359-363.
USFS-BLM. 2005. Species fact sheet: Columbia River tiger beetle. Prepared by G. Brenner. Portland, Oregon.