Scott Optioservus Riffle Beetle

Photo by Kyle Gerstner
used by permission


Common Name: Scott Optioservus Riffle Beetle

Scientific Name: Optioservus phaeus




Dark Blue = Counties with designated critical habitat
Light Blue = Historical records


Federal Status:

State Status:

Comments: The only known place in the world where the Scott optioservus riffle beetle can be found is at Scott State Park. The Scott optioservus riffle beetle lives in cool water with a high concentration of dissolved oxygen. A short stretch of spring-fed stream is home to this diminutive beetle (0.1 inch length) which can be found clinging to rocks. The rocks provide the surface area where it grazes on diatoms and periphyton. The larva possesses gills at the tip of its abdomen and may remain at this stage for 2-3 years. After pupating, the adult beetle is winged and can fly short distances but soon returns to water and loses the ability to fly. Although the site is protected from development, the quantity and quality of groundwater entering the inhabited stream is of greater concern for the beetle’s continued survival.