Fly fishing flies: caddis 2
Sunday, 7 June 2015 | Simon
As promised, more on fly fishing flies, again on the big subject of the caddis. The caddis, unlike mayflies and stoneflies, undergoes a complete metamorphosis, from larva, pupa, and adult stages within a typical life cycle, rather than just a single nymph stage. Through the larval stage, caddis look like tiny, segmented worms. These wriggly beasts are classified as either “cased”or “free-living” caddis larvae.
Cased caddis spend their entire larval stage protected by a self-constructed case. These are cleverly and resourcefully made out of vegetation, gravel, and other tiny bits of debris and held together by a sticky silk secreted by the bug specifically for this purpose. Cased caddis are abundant in every kind of trout water you can imagine because of their aggressive nature and ability to feed on active, similarly-sized prey.
Free-living caddis larvae, on the other hand are found cruising on the river bottom. Equally they may hide beneath the shelter of spun silk "tents." This type needs strong in-flowing or out-flowing currents to survive because they make a living by trapping their food in bits as it flows by them - for them a much easier task than yours when you’re fly fishing!