Last updated on July 23rd, 2022 at 06:37 pm
The caddisfly is a type of fly that lives underwater and can be found in the temperate, tropical, and Arctic regions as well. This creature’s larvae have long thoracic legs that help it swim. They are typically brown or black with two sets of wings: one for flying above water and one for swimming under it.
The larvae are found on the bottom of water, rocks or plants and feed off decaying matter.
Adults do not eat solid food as they are too busy mating to find time to eat anything but their own bodily fluids!
Description
Caddisflies are insects of the order trichoptera. The larvae build cases made of small rocks, sand grains and bits of vegetation cemented together with silk from their mouths in which they hide during the day to protect themselves against predators such as fish or frogs.
The height and width of a caddisfly case varies depending on the species and age of the larvae. The case is called a caddis house or caddisfly tube, and will usually have two doors for going in and out.
Caddisfly cases are often found attached to rocks near waterfalls, streams or lakes where they feed on algae from the surface of stones.
Their larvae usually go through a series of 12-13 molts in which they grow from an inch long to three inches. The final molt causes the caddisfly larvae to change into pupae, and inside the cocoon, it undergoes metamorphosis where it finally turns into an adult fly with two wings.
Caddisfly larvae live in fresh water, and they can be found all over the world. These insects are important to freshwater habitats because their cases trap detritus from stream beds which helps capture sedimentation and keeps streams clean of debris.
Caddisfly scientific name
The scientific name is Hydropsyche. Caddisflies are important members of the food web because they eat dead organic matter that has fallen onto or been washed into their habitat, and in some cases, help transport it to other habitats by carrying it along with silk threads spun from glandular hairs on their legs.
What is a caddisfly larvae?
Caddisfly larvae are aquatic insects that live most of their lives underwater. They breathe through gills on the outside of their bodies and have a long tail which they use to swim against the current or in an up-and-down motion. When fully grown, caddisflies leave water as adults by crawling out onto vegetation along the water’s edge.
Caddisfly larvae identification

One of the most common aquatic insects in North America, their larvae are generally found near streams and rivers. Caddisflies spend their entire larval development underwater feeding on small particles they can filter from water or pick off a rock. When ready to pupate, adults will emerge at night for mating and then return to the water, where they shed their pupal case and turn into a fully-developed adult.
When dealing with caddisfly larvae, it is important to first identify the species of caddisfly in question. There are over 700 recognized North American species that can be common or rare depending on location. Next, you will need to determine if the caddisfly is a pest or not. Caddisflies are typically considered pests if they can become an agricultural nuisance, create disturbances in recreational areas such as pools and picnic grounds, or damage structures.
What do caddisfly larvae turn into?
When the caddisfly larvae grow to be adults, they transform into what are called “flying stones.” These animals have wings and can fly off in a straight line when disturbed. They live underwater for about six months before emerging from their watery habitat as winged creatures. Caddisflies use these wings primarily as protection against predators.
Caddisfly life cycle

Caddisfly life cycle is a form of incomplete metamorphosis. The first stage, called the larva or nymph, looks like an aquatic worm with two pairs of jointed walking legs on its thorax and no wing cases. It has three pairs of feathery gills (called cerci) protruding from between segments on its abdomen.
The caddisfly larva lives underwater, and gathers bits of sand, gravel or other small particles to build a protective case for itself out of silk secreted from glands near the rear end.
This behavior is called sifting or sorting; in most species the larvae do this with their maxillae which are movable plates in the head.
The larva attaches one end of a silk strand to an object and pulls it underwater where it deposits its sifting material, then ties off the other end to a rock or other anchorage so that when the caddisfly swims back up for air, any loose particles are left behind on the now-weighted silk line.
Caddisfly larvae go through a number of molts before entering the pupal, or cocoon, stage. The larva attaches itself to some underwater object and begins secreting its outermost layer – an opaque white casing that is called “the exuvia.” A new fly then emerges from this casing and climbs out of the water.
Caddisfly fishing
One of my favorite summer activities is caddisfly fishing. One Saturday morning, I got up early and headed out to the creek in search for a good spot. The water was icy cold on my skin as I waded through it but when you are looking for caddisflies, it’s worth the tradeoff.
Caddisfly fishing is a great way to spend the morning or evening. You can do it with friends, family or on your own. I’ve found that there are many different kinds of caddisflies and each one has its own unique style for catching them.
The most popular kind of fly used by fishermen is called an attractor fly. This fly is brightly colored and made with shiny materials that they can see from a distance, which makes it easier for them to be caught on your hook.
The most important thing about this type of fishing is patience. It may take quite some time before you get any bites so make sure you have plenty of canned goods and bottled water.
Or better yet, bring a buddy! They will often be found in small pockets of dead leaves at the bottom of the stream or creek so you may have to get your feet (or boots) wet. Don’t worry though; these insects are too light for humans to feel them crawling on their skin.
There are many different types of caddisfly fishing, but it’s always best to wear a mosquito repellent when you go out because they can be quite the nuisance! For some people, this is one of their favorite activities while for others, it may not seem worth all the work and planning that goes into it. However, for me it is the perfect way to spend a day.
Are caddisflies dangerous?
Caddisflies don’t pose a danger to humans, but their larvae can be dangerous. That’s because the most common caddisfly larva is called an “aquatic worm” or hookworm, and it spends its life infecting freshwater fish with tapeworms that are then consumed by humans.
Do caddisflies bite?
Caddisflies are not known to bite people, but they do have the potential. Some species can be aggressive and irritate some humans with their biting mouthparts. If you feel a caddisfly is too close for comfort or painful when it bites you, remove it from your skin by grabbing its head and pulling upward (you can also use tweezers).
Caddisfly pupa
The insect has now shed its larval skin and will transform into an adult fly inside this thick protective casing.
If it cannot find shade or shelter, such as in the wintertime, the pupal case serves to protect it from freezing until warmer weather comes along.
Summary – caddisfly facts
Caddisfly larvae are known as “hellgrammites” for their ferocious appetites. They can eat up to ten times their body weight per day, making them one of the fastest growing insects on earth.
Caddisflies spend most of their life underwater and a human-sized caddisfly would be about the size of a grain of rice.