Insect: Riffle Beetle Scientific Name: Class: Insecta Order: Coleoptera Family: Elmidae Metamorphosis: complete

Description: Larvae: Resemble small "torpedoes" with circular stripes or rings around body; pointed at both ends with a "fuzzy" mass at one end; color usually grayish; length less than half an inch. They may take three years to mature before they leave the water to form a pupa. Adults: Unique in that they are also aquatic and are found more often than the larvae; adults are beetle-like, tiny, and usually black. They have one pair of antennae. They walk slowly on the stream bottom, never on the surface. Mature body size is about two to four mm. They often live in fast moving and clean water. They are able to fly when they emerge from the water but lose this ability after they return to the water.

Discussion: Food: Primarily plant material such as diatoms and algae. They often eat woody debris. Indicator Role: Found in fast-moving waters, indicates ample oxygen supply. Reproduction: Females deposit eggs on plant materials under water.