English terms for types or instances of insects in the order Trichoptera, which are closely related to the butterflies and moths but with hairs on their wings instead of scales, and which have aquatic larvae that live in cases that they build around themselves.

NOTE: This is a set category. It should contain terms for caddis flies, not merely terms related to caddis flies. It may contain more general terms (e.g. types of caddis flies) or more specific terms (e.g. names of specific caddis flies), although there may be related categories specifically for these types of terms.