176 



ELEMENTAEY STUDIES IN INSECT LIFE 



Caddis-Flies. 1 - - These moth-like insects, small and 

 rather unattractive, are not frequently noticed. Though 

 possessed of two pairs of well-developed wings, they 

 do not use them readily in flight, so that the adults 

 rarely wander far from their place of emergence in 

 some stream, brooklet, or pool. The mouth-parts of 

 the adult are rudimentary, the metamorphosis com- 

 plete. The eggs are deposited in a mass surrounded 

 by jelly. Sometimes this mass contains as many as 

 one hundred eggs. 



FIG. 142. A caddis-fly (Leptocerus dilutus). 



Of greater interest than the adult, will be, to begin- 

 ners, the larva and its habits. The young caddis-worm 

 protects itself from fish and other enemies by con- 

 structing a house of sticks, pebbles, leaves and the like, 

 to be found in the water where it lives. The figure 

 (Fig. 37) represents but one of the many interesting 

 houses. Among the stones through which the waters 

 of a small stream is running such forms live. 



ORTHOPTERA. 



Insects of this order have biting mouth-parts, two 

 pairs of wings, the front wings being generally narrow 

 and the hind wings of more delicate texture, and fold 

 fan-like under the front wings; incomplete metamor- 



1 Family, Phryganeidae. 



