Cicindela arenicola

Distinguished from the closely related C. waynei (Bruneau Dune Tiger Beetle) by its generally bronze to coppery-red rather than green coloration, less expanded white markings, and absence of the upward-projecting tooth on the male mandible that characterizes C. waynei. Distinguished from C. theatina (Colorado Dune Tiger Beetle) and other C. maritima group species by geographic restriction to the Snake River Plain and specific sand dune habitat associations. Fresh adult burrows with flat, horizontally-angled tunnels can indicate presence when adults are not active.

Adults exhibit bold white maculations on the elytra, with green and copper metallic highlights on the head and pronotum. The sides and undersurface are covered with dense white hairs. The overall coloration ranges from coppery-red to greenish-red. Some individuals in south-central Idaho populations show green elytra with expanded white markings, resembling intergradation with C. waynei. The body is robust and adapted for rapid running on sand surfaces. Adults create distinctive burrows with flat, horizontally-angled tunnels that dive a few inches back into the sand.

Strictly associated with active sand dune ecosystems. Adults are found on sloping, south-facing dune faces above flatter sand plains, and in sparsely vegetated areas of dunes where they appear somewhat less wary than on open dune surfaces. Habitat has been degraded by invasive annual grasses (particularly downy brome, Bromus tectorum), cattle trampling, and off-road vehicular traffic.

Endemic to the Snake River Plain of southern Idaho, primarily the St. Anthony Dune system in southeastern Idaho where the species was first described. A small population also occurs in the Centennial Sandhills of southwestern Montana. The species has one of the most restricted ranges among North American tiger beetles.

Adults are most active during warm days in spring and fall. They retreat to burrows in the sand when conditions become very hot or cold. Adults hibernate during winter and emerge from burrows in spring to mate and lay eggs. Activity patterns are bimodal (spring-fall), with fall activity being somewhat less predictable depending on moisture availability.

Adults hibernate in burrows during winter and emerge in spring to mate and lay eggs. Larvae develop in burrows within the sand dune substrate; specific details of larval development and pupation have not been extensively documented. First instar larvae may be present over an extended period, making timing of management activities an important conservation consideration.

Adults are extremely active and wary, making them difficult to approach for observation or photography. They dig burrows in sand for nightly refuge and for shelter during excessively hot or cold conditions. Burrow placement appears non-random, with adults often digging in troughs between sand ripples where sand may be more stable. Adults in sparsely vegetated dune areas appear slightly less skittish than those on open dune surfaces. When disturbed, adults may dart away rapidly; their running capabilities make them challenging subjects for field photography.

As a predatory beetle, likely functions as an invertebrate predator within sand dune ecosystems. Larvae are known to be parasitized by tiphiid wasps in the genus Methocha, indicating a role in supporting parasitoid populations. The species' presence indicates intact, active sand dune ecosystems with minimal vegetational encroachment.

Considered for listing under the U.S. Endangered Species Act due to imperiled habitat status, though federal listing has not been accorded. Listed as globally imperiled by the Idaho Department of Fish and Game and the Bureau of Land Management. Subject of habitat restoration efforts using herbicides (particularly imazapic) to control invasive downy brome and restore native sand dune vegetation. Serves as a flagship species for sand dune conservation in the Intermountain West. Research on this species has contributed to understanding of sand dune tiger beetle ecology and conservation management techniques.

• Cicindela wayneiClosely related species formerly considered conspecific; differs in green rather than bronze coloration, more expanded white markings, and presence of upward-projecting tooth on male mandible. Restricted to Bruneau Dunes State Park in southwestern Idaho.
• Cicindela theatinaAnother C. maritima group endemic restricted to single sand dune system in Colorado; similar habitat and morphology but geographically separated and with different coloration patterns.
• Cicindela albissimaRelated sand dune endemic with vivid white coloration, restricted to Coral Pink Sand Dunes State Park in southwestern Utah; similar conservation status and threats.

• endemic
• sand dune specialist
• globally imperiled
• conservation
• C. maritima species group
• habitat restoration
• invasive species management

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• St. Anthony Dune Tiger Beetle | Beetles In The Bush
• Cicindelidae | Beetles In The Bush | Page 9
• Saving endangered species with herbicides | Beetles In The Bush
• ID Challenge #13 – Addendum | Beetles In The Bush
• Bruneau Sand Dune tiger beetles caught in the act! | Beetles In The Bush