630 



TEXT-BOOK OF ENTOMOLOGY 



The pupae of Coleoptera are variously spined or hairy (Fig. 586). 

 Those of Hydrophilus and of Hydrobius are provided with stout 

 spines on the prothorax and abdomen which support the body in its 

 1^ ^ggg cells, so that, as Lyonet first showed, nM ^_^__ 

 though surrounded on all sides by 

 moist earth, it is kept from contact 

 with it by the pupal spines; other 

 pupae of beetles, such as that of the 

 plum weevil, which is also subter- 

 ranean, possess similar spines. The 

 abdomen of many coleopterous pupae, 

 such as those of Carabidae, end in two 

 spines, to aid them in escaping from 

 their cells in wood or in the earth ; 

 others have stiff bristles, and others 

 spines along each side of the abdomen 

 (Fig. 586). All these structures are 

 the result of a certain amount of 

 activity in what we call quiescent 

 pupae, but most of these are for 

 use at the end of pupal life, at the 

 critical moment when by their aid the B *-~ 

 insect escapes from its cocoon or sub- O f Taianlsiiiieota. 

 terranean cell, or if parasitic, bores out of its host. after h iiart. d Flg ' ^ 



If we are to account for the causes of their origin, 

 we are obliged to infer that they are temporary deciduous structures 

 due to the need of support while the body is subjected to unusual 

 strains and stresses in working its way out of its prison in the earth, 



FIG. r4. 1'upa 

 of Tipula eluta. 



a '& 



FIG. 586. Pupa of <;<ili>i-il<i f .<>// /. and of Adelopn Mrtus (a, b, c). After Hubbard. 



or its cell within the stems and trunks of plants and similar situa- 

 tions. They are pupal inheritances or heirlooms, and well illustrate 

 the inheritance of characters acquired during a certain definite, 



