ir. INSECT A: HEX APOD A. 



475 



ditions larvffi widely remote from the systematic standpoint may 

 closely resemble each other, while those of closely related sioecies 

 may differ extremely. The leaf -feeding larva3 of Leiiidoptera (fig. 



Fig. 501. 



Fig. rm. 



Fig. 501.— Pupa of Sp/it7i.r ;igi(.stri. (After Ludwie-Leunis.l I, eye ; i'. head ; ,5, an- 

 tennfe; A-«, thoracic somites ; 7, hind, .y, fore wing ; .'/, legs; w, probo,scis ; ii, ab- 

 dominal somites ; J2, spiracles. 



Fig. 502.— Larva of Sphinx Ugustri. (After Ludwig-Leunis.) ?i, caudal disc ; p^ tho- 

 racic feet ; p.s, prolegs. 



Fig. 503.— Larva (maggot) of blowfly, Musca voniitorUt. (After Leuck:art.) 



502) and Tenthreds are brightly colored, the thoracic appendages 

 remaining small, and are reinforced by the fleshy ventral apj^end- 

 ages, the prolegs or pedes sijurii. The jn-edacious larvae of many 

 beetles and Neuroptera have long thoracic leg.«, strong mandibles, 

 and no prologs. Other beetle larva?, which burrow in wood or 

 live in the earth (fig. 500), have plump whitish bodies, with the 

 legs rudimentary or wholly lacking. These lead to the maggot- 

 like larva3, in which the mouth parts are inconspicuous and the 

 distinction between head and thorax may vanish. Such soft-skinned 

 annulated sacs occur in the bees (fig. 50) and other llymenoptera, 

 as well as in many flies (fig. 50.3) ; that is, in animals which live 

 in an abundance of food either because of parasitism or because 

 the mother has jirovided plenty. 



From the outer appearance one would gain the impression that 

 these holometabolous larvaj not only lacked the wings, but that the 

 appendages of the imago were entirely absent or had an entirely 

 different form ; farther, that wings, and frequently antenna^, legs, 

 and mouth parts, come into existence at the moment of pupation, 

 and then in remarkable size and completeness. A more accurate 

 investigation shows that the anlagen of all these structures are 

 formed long before jiupation, often at the first molt. The wings 



