Have you seen any of these dragonfly nymphs?
Aquatic insects are all of those little bugs that you find in rivers, lakes, and ponds. Here are 6 common aquatic insects that you are likely to see in the Rocky Mountains.
I have to admit that I find aquatic insects pretty cool. One of the reasons that I am into these bugs is because I enjoy fly fishing. As a fly fisher it’s important to understand all about the different bugs in and on the water because that is what the fish eat. If I can figure out what stage in the lifecycle of a bug the fish are eating I can mimic it and hopefully catch a fish. These bugs are cool even if you don’t fish.
Insect Lifecycle – Metamorphosis
Before I talk about the common water bugs you may find I want to remind you about insects lifecycle. All insects undergo metamorphosis. This is when they change their physical shape from their nymph/larvae form (immature) to their adult form.
Most of these common bugs I’m about to list have a nymph stage that lives underwater and an adult stage where they are a winged insect. That is a big change in the life of an animal and I think it’s pretty cool to see both the nymph and then the winged adult.
6 Common Aquatic Insects Of The Rocky Mountains
An adult mayfly holds its wings up like a sail when resting.
Mayfly
A mayfly has an interesting lifecycle. It is a tiny bug that spends most of its life underwater as a nymph (up to 2 years). Then when ready it emerges and changes into a winged adult. It has one of the shortest adult lifespans of all animals, living for a few hours to days. Its sole purpose as an adult is to mate.
Mayflies hold the distinction of being the only winged insect that undergoes a change as an adult. It changes from a non-reproductive dun, to a spinner that is able to reproduce.
Read some fun facts about mayflies here.
An adult caddisfly holds its wings like at tent over its body at rest.
Caddisfly
A caddisfly is another water bug that spends most of its life as a nymph underwater. It has a similar lifecycle to a mayfly.
The nymph is unique in that it builds a case around itself out of tiny pebbles, sands, sticks, and such. This case protects it.
The adult emerges and becomes a winged insect whose goal again is to reproduce.
This water strider spreads out its legs so that it can ‘float’ on the surface of the water.
Water Strider
A water strider lives on the surface of water. It has the amazing ability to skate along the surface of the water.
It uses water tension to stay afloat by spreading apart its legs and distributing its tiny weight to stay afloat. It is a predator, so it skates around the water looking for small insects to eat.
Read these other facts about water striders.
A stonefly. Photo via Flickr.
Stone Fly
This is another insect that lives most of its life underwater as a nymph and then emerges to become a winged adult. A stonefly nymph is similar to, but bigger than a mayfly nymph.
The adult of most stoneflies does not feed. Its primary goal is to reproduce.
A water boatman swimming underwater.
Water Boatman
This aquatic insect lives in the water all the time. The adult doesn’t come out of the water to live. It does breathe air, but it spends most of its time diving underwater where it eats plants.
Now and then it comes to the surface of the water to get some air. It then holds an air bubble under its body that it brings under the water with it to breathe while it feeds.
A dragonfly.
Dragonfly
A dragonfly is a voracious predator, both as an adult and a nymph. The nymph lives underwater and eats other insects. Then when ready, it crawls out of the water and the winged adult emerges out of the shed skin. Check out these 5 facts about dragonflies.