CHAPTER XVII. 



Order Trichoptera (Tri-chop'te-ra). 

 The Caddice-fiies or Caddice-worms. 



The members of this order have four zvings ; these are 

 membranous, furnislied with numerous longitudinal veins but 

 with only few cross veins, and are more or less densely clothed 

 with hairs. The month-parts are rudimentary. The meta- 

 morphosis is complete. 



The Caddice-flies are moth-like insects which are com- 

 mon in the vicinity of streams, ponds, and lakes ; and they 

 are also frequently attracted to lights at night. 



The body-wall of these insects is soft, being membran- 

 ous or at the most parchment-like, and is thickly clothed 

 with hairs. There are usually four ample wings. These 

 are membranous ; but the fore pair are more leathery than 

 the hind pair. When not in use they are folded against 

 the sides of the abdomen, in an almost vertical position, 

 and give the insect a narrow and elongated appearance 

 (Fig. 225). The wings are more or less densely clothed 



with hairs ; and in some cases the 

 hairs are scale-like in form. The hind 

 wings are usually broader than the 

 fore wings, and are often longitudi- 



F.G. -Caddice-fly. naUy folded j n repose AU haye „„. 



merous longitudinal veins, but the cross veins are few. 



The name of the order is from two Greek words : thrix, 

 a hair; and pteron, a wing. 



The order includes only a single family, the Phryganeidce. 



186 



