Atractelmis

Distinguished from other elmid genera by combination of small size (2 mm), shiny black coloration with four red elytral spots, and specific habitat association with mountain stream riffles at 600–1,500 m elevation. The red spotted pattern on black background is distinctive among western North American elmids.

Riffles of rapid, clear mountain streams at elevations of 600–1,500 m (2,000–5,000 ft). Both adults and larvae inhabit the same microhabitats, typically occurring within aquatic mosses, particularly Platyhypnidium riparioides.

Endemic to the western United States, specifically California, Oregon, and Idaho. The type locality is Wawona in Yosemite National Park, California.

Adults and larvae co-occur in the same microhabitats. Larval development occurs within stream riffles. Specific developmental stages and duration unknown.

Easily overlooked despite potential for locally numerous populations. Both life stages remain within aquatic moss substrates in fast-flowing water.

Member of riffle beetle assemblage in mountain stream ecosystems. Role in nutrient cycling and food web dynamics typical of elmids but not specifically documented for this genus.

Named after Wawona in Yosemite National Park, reflecting historical entomological survey work in protected western U.S. landscapes. No documented economic or direct human interactions.

• Other Elmidae generaAtractelmis is distinguished by its specific combination of small size, red-spotted elytra, and strict association with high-elevation mountain stream riffles. Most other western elmids lack the distinctive four-spot pattern or occur at different elevations.

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• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life