Order TRICHOPTERA. 



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

 make cases or tubes of stones, sticks or other fragments of vegetable, 

 animal or mineral matter among which they live. They are aquatic, 

 resemble caterpillars in shape, but have the thoracic legs very long, the 

 others very short or obsolete, and the hind body soft because of the pro- 

 tection afforded by the case. 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, an 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, 

 often a little thicker in texture and covered with a fine hair, which some- 

 times becomes scale-like. The mouth parts are mandibulate in type, but 

 are rarely well developed, and in many cases so nearly obsolete as to be 

 entirely useless for feeding purposes. They have many resemblances to 

 the Lepidoptera, and some of the species of either order may be readily 

 taken for members of the other. It is believed that in the Trichoptera we 

 have the direct ancestors of the Lepidoptera. 



Fig. 22. Caddice-fly cases of varying types. 



Collections in this order are not much more complete than they were at 

 the time of the previous edition, and comparatively few new species have 

 been added. Some of the species added as probabilities have been veri- 

 fied, and a very few of these have been omitted as unlikely to occur from 

 better knowledge. 



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