Cased Caddisflies in Alberta Lakes

Most of the larger species of caddisflies found in Alberta Lakes are in the families Limnephlidae and Phryganeidae. Both groups have some interesting case building behaviors, with each case designed to help the larva blend into its environment and avoid predators. Natural materials are scavenged and arranged in ways the enhance the camouflage provided by the case. Note that these photos were purposely taken with each caddisfly larva in an unnatural setting to make them more visible in the photos.

Anabolia bimaculata (Limnephilidae) with a case of longitudinally arranged pieces of dead grass. This species tends to prowl along the edges of lakes and ponds where emergent sedges and grasses predominate.

Sometimes case construction is specific to a species and sometimes it will vary. This Anabolia bimaculata larva was collected from a pond lined with spruce trees - case construction using dead spruce needles made more sense than lengths of dead grass.

Members of the family Phryganeidae tend to arrange the case material in a spiral pattern. Fabria inornata uses short lengths of plant stems arranged in a lose spiral (better seen in the next photo).

Philarctus quaeris (Limnephilidae) larva have a habit of picking up seeds or snail shells to assemble their case. Some cases may be built entirely of small snail shells. This larva has decide to use Daphnia egg cases (ephippia) that have settled to the bottom.

Caddisflies are closely related to the Lepidoptera (moths and butterflies). And like caterpillars, caddisfly larvae can produce silk from glands near their mouth, which they use to line their case and hold it all together.

If you have the patience to fish a cased caddisfly pattern in lakes, it can produce some nice fish. The trick is to keep your fly on or near the bottom, and move it ever so slowly. Fly patterns are usually quite simple - I have seen woolly worms with the palmered hackle trimmed short work well. One of my favorite patterns imitates the larva of Phryganea cinerea (Phryganeidae) with its case of spirally arranged short pieces of grass.