Rock-Hard Caddis Larvae

Make durable and amazingly realistic cased caddis larvae.

by Nadica & Igor Stancev

Many fly fishermen try to match the hatch by matching the insects they find living under rocks in the river. They’ll rummage under stones to find the insects and select an imitation that they hope will help catch fish. Among the wide variety of aquatic insects, caddis larvae are the easiest to recognize and collect. They are also a favorite food of trout and grayling, and are accessible to the fish throughout the year.

Caddisfl ies belong to the order Trichoptera, which means “hairy wing.” Some caddisflies are predators and feed on other insects. Other caddisflies are scavengers; they feed on the carcasses of small dead animals. And finally, some caddisflies are herbivores, which feed on algae and other plant life.

Glyphotalius pellicidus, from the family Limnephilidae, uses plant material to build its protective case. This larva inhabits the calm parts of a river.

An Odontoceridae larva closes the end of its case using a single small stone.

A Brachycentrus subnubilus larva, from the family Brachycentridae, builds a square 12-millimeter-long case using plant material. The pale green larva develops into the famous Grannom adult caddisfly.

Some species of caddisflies spend their larval stages in protective cases they construct. Most predator larvae do not live in cases; they build small nets, similar to spiderwebs, to catch their prey. Herbivores and scavengers, however, live in protective shelters. The shape and construction of these small houses vary with each species. Caddisflies build their cases using either plant matter, tiny pebbles, or both. A case must be big enough so a larva can hide inside, yet small enough so the insect can maneuver and search for food.

A larva has filamentous gills on its body to filter oxygen from the water that flows through the case. All immature development stages—even the beginning of the pupa stage—occur inside the case.

Beadhead Cased Caddis

Hook: 2X-long nymph hook, sizes 14 to 8.
Thread: Brown 8/0 (70 denier).
Head: Black bead.
Weight: Lead wire.
Thorax: Fluorescent green dubbing.
Legs: Brown partridge or hen feather.
Case: dried sand and grit from your local stream.
More stuff: Clear silicone and varnish.

Tying the Cased Caddis Using Dubbing and Sand
All in the Family

Seven families of caddisflies build protective houses from materials of mineral origin: Sericostomatidae, Odontoceridae, Beraeidae, Brachycentridae, Lepidostomatidae, Leptoceridae, and Limnephilidae. The last four families build A Sericostoma larva builds a cylindrical, slightly curved case from fine sand. The case is smooth and measures 12 to 16 millimeters long. cases using a combination of tiny stones and plant matter.

A Leptoceridae larva uses mainly sand, mixed with plant particles, to build a long, slim case. This is the second most common family of caddisflies.

Limnephilidae live in all water types but generally prefer water that has a slow-moving or weak current. There are 7,000 identified species to the order Trichoptera, and about one-quarter belong to the family Limnephilidae. Limnephilidae build tubelike houses using different mineral and organic materials such as sand, leaves, empty snail houses, moss, and more. They tend to move slowly and usually feed by browsing for algae or scavenging animal remains.

Leptoceridae, with 45 genera and 1,500 species, is the second-largest family of caddisflies. Extra-long antennae are an adult Leptoceridae’s main identification characteristic.

Brahycentridae live in cold trout rivers. The Grannom caddisfly is the most famous representative of this family. The larva is pale green and builds a 12-millimeter-long, reddish brown square shelter that tapers toward the tip end. The walls of the case are made out of pieces of grass glued together using secretions produced by the insect.

Sericostomatidae larvae build cylindrical, slightly curved cases out of sand and gravel. Sericostomatidae cases are smooth and measure 12 to 16 millimeters long. .Odontoceridae contains only one species:Odontocentrum albicorn. These larvae build smooth cases using fine sand. The cases taper at the end, are slightly curved, and are 20 millimeters long.

Beraeidae larvae build smooth, curved cases using fine grains of sand.

Lepidostomatidae, also known as the plain little brown sedge, build tubular, slightly tapered cases. The tying methods we are going to study are ideal for crafting imitations of Lepidostomatidae larva cases.