Caddis Fly Larvae

I came across a lot of Trichoptera (caddis fly) larvae during research lately and became fascinated by these guys.
If you aren't familiar with them already, then here's what you need to know...

Caddis flies are an order of insect that are moth-like in the adult stage of their life cycle. But their larvae are aquatic. They only really develop legs at the front of the body:

Why?... Because the rest of the body is encased in a tube made by the larva itself from sediments, particulate organic matter and whatever else they can find, bound together with a kind of silk.

Some make these distinctive cases very smooth by using fine sediments:

others use larger grains:

and some use other random things they find, like bits of plant stems..

Artists have taken interest in them too. Hubert Duprat worked with Caddis fly larvae in the 1980s. He removed them from their natural cases and put them in a tank with flakes of gold and precious gems, like pearls, rubies and saphires. The larvae used the given materials to make these cases:

Jen