Fluttering Caddis
Fly of the Month
Our Caddisflies series will be presented in three parts. Part One will cover the adult stage, Part Two will cover the pupa stage and Part Three will cover the larva stage. We have selected a Fluttering Caddis fly pattern that closely represents or imitates the adult stage that is most typically observed on our water. Caddisflies effectively flutter their wings to hover over the water to search for a mate, to actually mate and for many species, actually drop eggs into the water or lay eggs.
Caddisflies are very abundant aquatic insects in our typical Southern Appalachian mountain trout streams. Caddisflies tolerate a slightly more acidic pH water conditions than mayflies and the adult stage is more available during daylight hours compared to stoneflies.
Fluttering Caddis – Part One – Adults
Caddisflies or Trichoptera are an order of insects that live both in water and on land. An angler is most interested in the many aquatic species that spend most of their lives in water, especially lakes, ponds, or slow-moving portions of streams. Because fish feed on the immature, aquatic stages and trout take flying adults, caddisflies are perfect models for our artificial flies used in fly fishing.
There are over 1,100 species of caddisflies in the United States. Also called sedge-flies or rail-flies, they are small moth-like insects characterized by four wings or two pairs of hairy membranous wings. They are not strong fliers and flutter a lot like moths. The antennae are long and slender and are usually about the length of the anterior wing, but they may be longer than the wingspan. Mouthparts have nonfunctional mandibles. Each of the three thoracic segments bears a pair of walking legs. Adults are usually attracted to lights and active at night, and they rarely go far from the water where they were born. They are closely related to moths and butterflies or Lepidoptera which have scales on their wings, and the two orders together form the superorder Amphiesmenoptera.
Caddisflies were long classified in the order Neuroptera. However, the two groups are now thought to represent different evolutionary lines. Ancestral scorpionflies or Mecoptera probably gave rise to the lacewings or Neuroptera, caddisflies or Trichoptera as well as moths and butterflies or Lepidoptera. The closely related Trichoptera and Lepidoptera may have arisen from a common offshoot. Early aquatic trichopterans may have diverged from the terrestrial line about 200 million years ago in the Late Triassic Period. The earliest known trichopteran fossils are 185 million years old from the Early Jurassic Period. Many fossils in Oligocene Baltic amber from about 34 million to 23 million years ago, belong to or are related to living genera. Later fossil wing prints occur in Miocene deposits.
Although caddisflies may be found in waterbodies of varying qualities, they are generally thought to be an indicator of clean water. Together with stoneflies and mayflies, caddisflies feature prominently in bio-assessment surveys of streams and other water bodies. Caddisfly species can be found in all stream habitats, with some species being either predators, leaf shredders, algal grazers, or collectors of particles from the water column and benthos.
Caddisfly adults sometimes emerge in large numbers, often forming swarms. Caddisflies adults live several weeks but can sometimes last for two months and usually mate on vegetation or rocks surrounding water. There is generally one complete generation per year. The typical lifecycle pattern is one of larval feeding and growth in autumn, winter, and spring, with adult emergence between late spring and early fall, although the adult activity of a few species peaks in winter.
Most adult caddisflies are equipped mainly to mate, incapable of feeding on solids and instead imbibe nectar from flowers. Once mated, the female caddisfly will lay eggs as a gelatinous mass that swells on contact with water in masses numbering up to 800 above or below the water surface. A female may wash off a partially extruded egg mass by dipping her abdomen into water during flight, or she may place the mass on stones in the water or on aquatic plants just above the water. Eggs hatch in about three weeks.
Adult caddisflies are commonly 3 to 15 millimeters in length. Antennae are long and many jointed with a large basal segment. Their anterior wings usually range from 4 to 20 millimeters in length. The wings at rest are folded roof like and cover the top of the abdomen. One family, Hydroptilidae, commonly known as Microcaddis, are only 1.5 millimeters in length, with anterior wings of 2 to 5 millimeters. Caddisfly wings either are covered with hairs or have hairs on the veins. Posterior wings are often broader than anterior wings and the pattern of veins is generalized and sometimes reduced.
Caddisflies are important as food for other animals. Freshwater fish, particularly trout, and eels feed on larvae and swimming pupae. Trout, birds, lizards, frogs, spiders, dragonflies, and bats feed on adults. Day flight of caddisflies includes stationary swarming, usually centering around some obvious object on the shore, or mobile swarming, in which the swarms seem to move haphazardly. However, most species fly at night and are strongly attracted to light. Warm moist nights are particularly conducive to caddisfly flight.
A caddisfly is fairly easy to identify. When flying over or near water, they take on a moth-like appearance, fluttering their wings constantly. Unlike a small butterfly or skipper which will tend to flutter then glide. Keep in mind that moths are generally nocturnal, thus, a moth-like insect on the stream in daylight is more likely to be a caddis fly. It is fairly easy to capture a caddisfly for closer observation as they tend to fly with a hover-like, slow and erratic pattern.
In the resting position in your hand, a caddisfly will fold their wings in a tent-like fashion, not flat like a stonefly or midge nor upright like a mayfly. Note the color of the body and the shade of the wings. A simple match of the body color is generally effective for imitation. In rare cases, matching the shade - dark, medium or light - of the wings may be important as well.
Fly of the Month 5.16
Fluttering Caddis
- Tom Adams, Alen Baker
Our Caddisflies series will be presented in three parts. Part One will cover the adult stage, Part Two will cover the pupa stage and Part Three will cover the larva stage. We have selected a Fluttering Caddis fly pattern that closely represents or imitates the adult stage that is most typically observed on our water. Caddisflies effectively flutter their wings to hover over the water to search for a mate, to actually mate and for many species, actually drop eggs into the water or lay eggs.
Caddisflies are very abundant aquatic insects in our typical Southern Appalachian mountain trout streams. Caddisflies tolerate a slightly more acidic pH water conditions than mayflies and the adult stage is more available during daylight hours compared to stoneflies.
Fluttering Caddis – Part One – Adults
Caddisflies or Trichoptera are an order of insects that live both in water and on land. An angler is most interested in the many aquatic species that spend most of their lives in water, especially lakes, ponds, or slow-moving portions of streams. Because fish feed on the immature, aquatic stages and trout take flying adults, caddisflies are perfect models for our artificial flies used in fly fishing.
There are over 1,100 species of caddisflies in the United States. Also called sedge-flies or rail-flies, they are small moth-like insects characterized by four wings or two pairs of hairy membranous wings. They are not strong fliers and flutter a lot like moths. The antennae are long and slender and are usually about the length of the anterior wing, but they may be longer than the wingspan. Mouthparts have nonfunctional mandibles. Each of the three thoracic segments bears a pair of walking legs. Adults are usually attracted to lights and active at night, and they rarely go far from the water where they were born. They are closely related to moths and butterflies or Lepidoptera which have scales on their wings, and the two orders together form the superorder Amphiesmenoptera.
Caddisflies were long classified in the order Neuroptera. However, the two groups are now thought to represent different evolutionary lines. Ancestral scorpionflies or Mecoptera probably gave rise to the lacewings or Neuroptera, caddisflies or Trichoptera as well as moths and butterflies or Lepidoptera. The closely related Trichoptera and Lepidoptera may have arisen from a common offshoot. Early aquatic trichopterans may have diverged from the terrestrial line about 200 million years ago in the Late Triassic Period. The earliest known trichopteran fossils are 185 million years old from the Early Jurassic Period. Many fossils in Oligocene Baltic amber from about 34 million to 23 million years ago, belong to or are related to living genera. Later fossil wing prints occur in Miocene deposits.
Although caddisflies may be found in waterbodies of varying qualities, they are generally thought to be an indicator of clean water. Together with stoneflies and mayflies, caddisflies feature prominently in bio-assessment surveys of streams and other water bodies. Caddisfly species can be found in all stream habitats, with some species being either predators, leaf shredders, algal grazers, or collectors of particles from the water column and benthos.
Caddisfly adults sometimes emerge in large numbers, often forming swarms. Caddisflies adults live several weeks but can sometimes last for two months and usually mate on vegetation or rocks surrounding water. There is generally one complete generation per year. The typical lifecycle pattern is one of larval feeding and growth in autumn, winter, and spring, with adult emergence between late spring and early fall, although the adult activity of a few species peaks in winter.
Most adult caddisflies are equipped mainly to mate, incapable of feeding on solids and instead imbibe nectar from flowers. Once mated, the female caddisfly will lay eggs as a gelatinous mass that swells on contact with water in masses numbering up to 800 above or below the water surface. A female may wash off a partially extruded egg mass by dipping her abdomen into water during flight, or she may place the mass on stones in the water or on aquatic plants just above the water. Eggs hatch in about three weeks.
Adult caddisflies are commonly 3 to 15 millimeters in length. Antennae are long and many jointed with a large basal segment. Their anterior wings usually range from 4 to 20 millimeters in length. The wings at rest are folded roof like and cover the top of the abdomen. One family, Hydroptilidae, commonly known as Microcaddis, are only 1.5 millimeters in length, with anterior wings of 2 to 5 millimeters. Caddisfly wings either are covered with hairs or have hairs on the veins. Posterior wings are often broader than anterior wings and the pattern of veins is generalized and sometimes reduced.
Caddisflies are important as food for other animals. Freshwater fish, particularly trout, and eels feed on larvae and swimming pupae. Trout, birds, lizards, frogs, spiders, dragonflies, and bats feed on adults. Day flight of caddisflies includes stationary swarming, usually centering around some obvious object on the shore, or mobile swarming, in which the swarms seem to move haphazardly. However, most species fly at night and are strongly attracted to light. Warm moist nights are particularly conducive to caddisfly flight.
A caddisfly is fairly easy to identify. When flying over or near water, they take on a moth-like appearance, fluttering their wings constantly. Unlike a small butterfly or skipper which will tend to flutter then glide. Keep in mind that moths are generally nocturnal, thus, a moth-like insect on the stream in daylight is more likely to be a caddis fly. It is fairly easy to capture a caddisfly for closer observation as they tend to fly with a hover-like, slow and erratic pattern.
In the resting position in your hand, a caddisfly will fold their wings in a tent-like fashion, not flat like a stonefly or midge nor upright like a mayfly. Note the color of the body and the shade of the wings. A simple match of the body color is generally effective for imitation. In rare cases, matching the shade - dark, medium or light - of the wings may be important as well.
Fly of the Month 5.16
Fluttering Caddis
- Tom Adams, Alen Baker