Order TRICHOPTERA. 



The " caddice " or "case-flies," are so named from the fact that the larvae 

 make cases or tubes of stones, sticks and the fragments in which they live. 

 They are aquatic, resemble caterpillars in shape, but have the thoracic legs 

 very long, the others small or obsolete, the entire hind body being soft. 

 Usually they frequent running brooks, streams or ditches ; but some live in 

 water that is sluggish or almost stagnant. The adults have a free head with 

 distinct neck, a compact thorax, abdomen without anal appendages, and four 

 net-veined wings, the posterior folded under and covered by the anterior. The 

 antennae are usually very long, the fore-wings are narrower than the hind- 

 wings and are covered with fine hair which sometimes becomes scale-like. In 

 texture the primaries are sometimes a little stouter and, altogether, the insects 

 at rest very much resemble moths. The mouth parts are obscurely mandibu- 

 late and, in a few cases, fairly developed ; but in many others they are so rudi- 

 mentary as to be entirely useless for feeding purposes. It is believed that in 

 the Trichoptera we have the direct ancestors of the Lepidoptera. 



The species are quite numerous, and have not been much collected : it is 

 very probable, therefore, that many additions will be made to the list in the 

 future. As a whole they are indifferent to the farmer. 



Fig 27. — Caddice-fly cases of varying types. 



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