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Insects That Eat Algae

By Harold Greengrass
Algae provides oxygen and food for thousands of forms of aquatic life.

Algae are a sprawling green or blue-green group of organisms which belong to the Paraphyletic group. Like plants, algae uses chlorophyll to capture light and convert it to sugar; however, algae is not scientifically considered to be a plant. Algae is very beneficial to aquatic life as it intakes animal waste for its nitrogen, expels oxygen and provides food for various forms of aquatic life. While many animals, like salamanders and frogs, eat algae, many insects also consume the it.


Sensitive to water pollution, mayflies are often found in ponds in clear, swiftly moving streams or ponds. From the order Ephemeropteral, mayflies in their nymph stage tend to consume algae found on stones or submerged weeds. An interesting fact about mayflies is that they have a special preadult phase in which they can fly; however once it sheds its adolescent skin, the mayfly returns to the water to feed, mate or swim.

Caddis Flies

Caddis flies appear in two varieties: ones that live in streams and become carnivorous and ones that live in ponds and make protective "cases" out of twigs and leaves. The latter sort of caddis fly feeds on algae while the former creates webs to catch prey floating in the stream. Marginally tolerant of pollution, both types of caddis fly can absorb stray nutrients from the water.

Water Boatmen

Water boatmen are a type of water bug which live in slow moving waters like ponds or lakes. These nonpredatory creatures feed through beaks, using their tubes and saliva to break down algae and plant matter into a liquid form that can be easily absorbed. Water boatmen usually travel in groups and are eaten as a dessert in some parts of Mexico.


Backswimmers do actually swim on their backs, using their hind legs to propel them through the water, though they cannot walk on land. These predatory insects are identified by their large eyes, curved backs and red eyes. Besides eating algae and plant life, backswimmers have been known to eat small aquatic creatures like fish and tadpoles, but they have also been observed pursuing larger prey like salamanders.


About the Author


Based in Austin, Texas, Harold Greengrass has been writing articles for local publications since 2003. His work has appeared in "Marinecreek Reflections" and the "Rio Review." Greengrass is a graduate of Naropa University's Jack Kerouac School of Disembodied Poetics.