What Does a Riffle Beetle Eat?

Riffle beetles commonly live in and along streams and their presence is a positive factor in determining the health of a waterway. The small beetles are less than 1/3 inch long when fully mature and can often be noticed walking slowly along rocks under the water. When a riffle beetle first hatches, he may fly to a new area miles away, and will spend the rest of his life feeding on vegetative matter in and near the water in that same area.

What's For Dinner

Riffle beetles help clean streams by feeding on organic decay found in the water. The riffle beetle prefers vegetative matter, such as decaying leaves, rotting plants and microscopic algae, but may also occasionally nibble at bits of carrion in the water. When decaying matter is scarce, the riffle beetle will expand his culinary tastes to include living plant material as well.