376 W. D. FUNKHOUSER 



are likely to be prominent, and the ocelli and the antennae not distinguish- 

 able. If the species is a pubescent one the hairs are usually not developed 

 in this instar. No wing pads are visible from an external view and the 

 abdomen is somewhat attenuated. The pronotum is not developed and 

 the prothorax is about equal in size to the other thoracic segments. 



In the second instar the size is usually doubled and the entire insect 

 is much darker in appearance. The prothorax is inclined to be swollen 

 dorsally but no distinguishing protuberance of the pronotum is apparent. 

 No whig pads are visible. The head is more normal in comparative 

 size and the eyes are not so promment. The ocelli may usually be dis- 

 tinguished and likewise the antennae. The spines are still very complex 

 and branched but seldom appear on the head. The anal segment of 

 the abdomen is generally prolonged and the entire body is stouter. 



In the third instar the characteristic enlargement of the pronotum 

 begins to appear and the wing pads are evident. The prothorax is much 

 larger than the other two thoracic segments. The head is normal in 

 size and the eyes are usually not prominent. The antennae are plainly 

 to be seen. The spines have lost much of their complexity and are much 

 shorter and less branched. In this stage the spines of the head and the 

 thorax are often entirely wanting and the whole body develops pubescence. 

 The anal segment of the abdomen is still much enlarged and the anal 

 tube is prominent. 



In the fourth instar the pronotal enlargement is prominent, the posterior 

 process usually covering the mesothorax. The wing pads are large and 

 well developed, usually extending posteriorly as far as the third abdominal 

 segment. The head is reduced in comparative size, the ocelli are 

 prominent and the antennae are normal. The spines are much reduced 

 in complexity if not in size. Often they appear as mere stubs or bristles, 

 and are seldom on any other part of the body than the abdomen. The 

 insect has increased much in size and often shows colors characteristic 

 of the adult insect. 



The fifth and last instar is usually the longest in duration and is by 

 many authors called the pupa, tho by what authority is not clear. The 

 activities of the insect are apparently in no way different from what 

 they were in the preceding stages, and there is certainly no quiescence 

 nor transformation that would justify the name. It is in fact confusing 

 to apply the term pupal stage to msects having such a representative 



