The Life-History and Anatomy of Moths 



Fig. 5. — Pupa of Tclca 

 polyphemns. (Riley.) 



encased in hard chitinous rings and sheathings. As a measure of 

 protection during this stage, the insect, before transforming into a 

 pupa, descends into the earth, and forms there a ceil at a greater or 

 lesser depth beneath the surface, or else weaves a cocoon of silk 



about its body. In some cases the 

 transformation takes place at the 

 surface of the earth under leaves or 

 under fallen branches and the loose 

 bark of trees. In almost all such 

 cases there is apparently an at- 

 tempt, though often slight, to throw 

 a few strands of silk about the body 

 of the caterpillar, if only to hold in 

 place the loose material amidst which transformation is to occur. 

 The forms assumed in the pupal stage are not as remarkably 

 diversified as in the larval or imaginal stages. The pupae of 

 moths are generally brown or black in color, though a few are 

 more or less variegated. The bright golden and silvery spots 

 which ornament the pupae of many species of butterflies, causing 

 them to be called chrysalids, are seldom, if ever, found. 



While the change into a pupa might at first sight appear to 

 the superficial observer to be disadvantageous because of the loss 

 of motion and the imprisonment 

 within narrow bounds, it neverthe- 

 less distinctly marks a progression 

 in the life of the creature. The pupal 

 case contains within it the moth, as 

 may easily be ascertained by a care- 

 ful dissection made in the very earliest 

 period after the change has occurred, 

 and which becomes very evident at a later time when the period 

 of the pupal life is drawing to its close. 



In the cocoon or in the cell in which pupation has taken place 

 will always be found the exuviae, or the larval skin, etc., of the 

 caterpillar, which have been cast off. 



When the time comes for the perfect insect to emerge from 

 the pupa, nature has provided methods by which escape from 

 the prison cell underground, or the tightly woven cocoon, can 

 be effected. In the case of those pupai which lie deeply buried 



Fig. 6. — Pupa of Cut-worm 

 in earthen cell. (Riley.) 



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