Riffle beetles
Elmidae · Aquatic life
Photo: Turner Brockman / CC BY-SA
Also called Elmids, Elmidae
How to identify Riffle beetles
- Tiny, dark, slow moving beetles about 1/16 to 1/8 inch
- Long legs with large claws for clinging to rocks and wood
- Do not swim; breathe from a thin silvery film of air on the underside
- Larvae are hard, narrow and segmented, often with a tuft of gills at the tail end
Similar species
Water pennies are flat and round like a coin. Crawling water beetles are yellowish with dotted wing covers and live in still water plant beds.
Profile
| Season | Present all year. |
|---|---|
| Starts | Present year round in cold flowing water |
| Depth | Rocks and wood on stream bottoms |
| How it spreads or reproduces | Adults fly to new waters, then stay underwater |
| Habitat | Rocks, gravel and submerged wood in clean, flowing streams, rivers and canals; a few on wave washed lake shores. |
Why it matters in a lake
Indicators of clean, well oxygenated flowing water. Rarely found in still, warm ponds.
Where it is found
- Idaho: Common
- Oregon: Common
- Wyoming: Common
Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Insecta |
| Order | Coleoptera |
| Family | Elmidae |
| Scientific name | Elmidae |
Midge larvae (bloodworms)
Mosquito larvae
Dragonfly nymphs
Damselfly nymphs
Water boatmen
Backswimmers
Predaceous diving beetles
Water striders
Mayfly nymphs
Caddisfly larvaeNeed a hand?
Found it in your lake?
Send us a photo and we will identify it and tell you what it means for your lake.
Idaho / Wyoming (208) 501-4531Oregon (541) 280-0596