Explanation of Names
Trichoptera = Greek 'hairy wing'
Caddis means cotton or silk; tape or ribbon of worsted yarn;
caddice men (vendors of ribbons, braids, etc.) pinned their wares on their coats
(1)
Identification
Adults resemble moths, but wings are hairy instead of scaly.
Forewings usually dark, sturdy, sometimes with striking color patterns, held tightly together roof-like over the abdomen when at rest.
Hindwings often clear, relatively delicate, and hidden under forewings when at rest.
Antennae usually very long, threadlike, with many segments.
Chewing mouthparts with prominent palpi.
Tarsi have five segments.
Ocelli (simple eyes) present in some families.
Keys to NA families & genera in
(5); keys covering local faunas in
(6)(7)(8)(9)(10)(11)...
The aquatic larvae have three pairs of legs and a soft, elongate, segmented abdomen usually hidden inside a case; head well-developed with chewing mouthparts in most species.
Most species live in a mobile case constructed from plant material, algae, grains of sand, pieces of snail shells, or entirely of silk. The case is held together with strands of silk secreted by the larva. In some species the case is attached to a rock, log, or other underwater surface; a few species have no case and are free-living.
The case's particular shape and construction material is distinctive of the family and/or genus, and can be used in identification. Example: Helicopyschidae larvae use sand grains to build spiral cases that resemble small snail shells.
Range
worldwide and throughout NA
ranges for each species of our fauna in
(12)Habitat
Species most diverse in well-aerated streams, but also occur in lakes, ponds, and marshes. Adults rest on nearby vegetation during the day; flight activity begins at dusk. Adults are attracted - sometimes in great numbers - to artificial light.
Food
Some adults take liquid food, such as nectar, others do not feed. Larvae usually detritivorous, some are predatory.
Life Cycle
Metamorphosis holometabolous. Usually one generation per year, sometimes several; some species take more than a year to develop. Depending on species, adults may be long-lived (30 days or more) or short-lived.
Remarks
Larvae are an important food item of fish, and are used as bait by anglers.
Most caddisfly larvae are intolerant of pollution; therefore, their presence is an indication of good water quality, and their absence in areas where they previously occurred may be an indication of polluted water.
The fungus
Erynia rhizospora infects adult caddisflies and causes them to die stuck to the undersides of rocks and logs in streams -- examples in
(13).
See Also
moths have scaly wings and a coiled
proboscis 
