In the Netherlands about 180 different species of caddisfly are occuring. Each species with its own habitat preference. They breath through their skin of with gills, finger like structures on their hind body. Caddisfly eat everyting, some species scrape algae from rocks, a few species are specialized in eating small pieces of leaves but it’s also possible they predate on their own species or other water insects. When growing caddisfly peel their skin 5 times. After 10 to 11 months the caddisflies are big enough to pupate. During pupation they anchor their case with extra material, such as pebbles. They withdraw themselves in their case and close it with a sieve plate of silk. Fresh water can pass the case, this is neccessary for breathing. After a few weeks the pupae leave their case, crawl out of the water and fly out, leaving their empty case behind.
Adult Caddisfly don’t live in the water but in the neighbourhood of water. Close related to butterflies they fly, mostly during dawn or in the night. The wings of Caddisfly range in size from een couple of mm untill 5 cm. They live a couple of days or months. During this time they mate and lay their eggs in or nearby water. Within a month the eggs come out and the larvae start a new live cycle in the water.