Caddis Fly Larvae

[The Yeti]

Weird question. Is it common for caddis fly larvae to be around this time of year? I thought all hatches of aquatic insects in our lakes up here happen early on?

[BRULEDRIFTER]

all macroinvertebrate larvae have multiple stages of development. there are always going to be larval forms around all year.

[The Yeti]

Reason I ask is that a friend found some squirming around in the sand off their dock. The larvae shell looks like a sand covered "cocoon". I'm assuming this is to blend in with surroundings?

[BRULEDRIFTER]

most caddisflies build cases. there are a few species that are free living, however. they build these cases for protection, and like a crab, as a home. they build them with a silk like thred, like a spider, and live their lives in them and add on as they grow. the cases also aid in respiration, as their gills are on the body and they utilize water currents that flow into the case and that is how they breathe. when they reach maturity, they close off the ends and morph into the adult (fly) form, like a cocoon. while inclosed in their cases they filter feed and leave enough space in both ends to allow the water to pass through. its been awhile since my aquatic entomology class, but im pretty sure i still have somewhat of a clue as to what im talking about

aquatic macroinvertebrates are so cool, especially the Trichopteras (Caddisflies).