35° 



COLLEGE ZOOLOGY 



some species the abdomen of the male terminates in a structure 

 resembling the sting of a scorpion. Little is known about the 

 habits of the Mecoptera. 



Order 14. Trichoptera. - — Caddice -flies (Fig. 282). — In- 

 sects possessing four membranous wings with many longitudinal 



veins and covered 

 with hairs ; rudi- 

 mentary mouth- 

 parts; metamorpho- 

 sis complete. 



The term caddice- 

 fly is derived from 

 the case (Fig. 282, A) 

 which its aquatic 

 larva builds of 

 leaves, grass stems, 

 or grains of sand as 

 a means of protec- 

 tion. The larva (B) 

 can extend the fore 

 part of the body 

 and drag its case 

 from place to place or can retreat into its house for safety. 

 Thread-like tracheal gills are present on the abdomen. Each 

 species builds a certain kind of case which can be distinguished 

 from those built by other species. 



Order 15. Lepidoptera. — ■ Butterflies, Skippers, and 

 Moths (Figs. 283-290). — Insects with four membranous wings 

 covered with scales; usually sucking mouth-parts; meta- 

 morphosis complete. 



The members of this order are famous for their varied and 

 brilliant colors; these are produced by the scales. The mouth- 

 parts form a sucking tube (Fig. 253) which may be five or six 

 inches long and is coiled under the head when not in use. This 

 sucking proboscis is used to obtain nectar from flowers. The 



Fig. 282. — Order Trichoptera. Stages in the 

 development of a caddice-fly, Enoicyla. A, case 

 of full-grown larva. B, larva and case enlarged. 

 C, larva removed from case. D, wingless adult 

 female. E, male. (From the Cambridge Natural 

 History, after Ritsema.) 



