416 



ARTHROPODA 



appressed to the body, so that only indistinct contours can be seen (fig. 

 459). Motion is confined to bending of the whole body, as is familiar 

 in the pupie of moths and butterflies. The pupa coarctata are without 

 motion because here the pupa (in structure a pupa libera) is enclosed in a 

 larger coat, the last larval skin (some flies). 



The variations among larva} are even greater than with pupa}. Here 

 structure is so completely under the influence of environment that with 

 similar or different conditions larvae widely remote, from the systematic 

 standpoint, may closely resemble each other, while those of closely related 

 species may differ extremely. The leaf-feeding larva} of Lepidoptera 

 (tig. 460) and Tenthreds are brightly colored, the thoracic appendages 

 remaining small and reinforced by the fleshy ventral prolegs. The pre- 



1 2 



st 



FIG. 459. FIG. 460. FIG. 461. 



FIG. 459. Pupa of Sphinx ligustri (after Lud \vig-Leunis). i, eye; 2, head; 3, 

 antenna;; 4-6, thoracic somites; 7, hind, 8, fore wing; 9, legs; 10, proboscis; n, abdomi- 

 nal somites; 12, spiracles. 



Fn;. 460. Larva of Sphinx ligustri (after Ludwig-Leunis). n, caudal disc; p, 

 thoracic feet; ps, prolegs. 



FIG. 461. Larva (maggot) of blowfly, Musca vomit or ia (after Leuckart). 



daceous larvae of many beetles and Neuroptera have long thoracic legs, 

 strong mandibles, and no prolegs. Other beetle larvae, which burrow in 

 wood or live in the earth, often have the legs rudimentary or wholly lack- 

 ing. These lead to the maggot-like larvae, 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. 59) and other 

 Hymenoptera, as well as in many flies (fig. 461); that is, larvae which live 

 in an abundance of food either because of parasitism or because the 

 mother has provided plenty. 



