254 



INSECT ORDERS 



water and some have a habit of covering their bodies with sticks, gravel, 

 and shells which adhere to them for protection. 



5. Dobson flies. The adult is a large vicious looking, but harmless 

 insect. The larvae live in water and are called hellgrammites by fisher- 

 men who consider them excellent fish bait, especially for bass. 



Order — Lepidoptera 



These are the butterflies and moths. They have two pairs of large 

 membranous wings, which are covered with overlapping scales that come 

 off like a fine powder when they are handled. The mouth parts are for 

 sucking, and the proboscis in some of them may be several inches long 



Fig. 17.11. Luna moth. 



Photo by Winchester 



Its beautiful pastel green wings are in contrast to the drab 

 coloration of most of the moths. 



and is coiled up under the head when not in use. Metamorphosis is com- 

 plete ; and the larvae are commonly called caterpillars and, unlike the 

 adults, have biting mouth parts. The butterflies are better known than the 

 moths because they fly in the daytime and usually have large colorful 

 wings that attract attention, but the moths are much more common and 

 their larvae cause great destruction to plants. However, the moths fly 

 at night and are not seen so often. The butterflies bear a knob at the 

 tip of the antennae, whereas the moth antenna is usually feathered or 

 may have a knob just short of the tip. The wings of the butterfly are 

 usually held erect over the back when at rest while those of the moth 

 are held folded down over the body. The moth larvae spin a cocoon 



