HETEROJMERA CANTIIARIDAE 



= 71 



devouring a couple of eggs, the triunguliu sheds its skin and 

 appears as a different larva (Fig. 140, B), with soft skin, short 

 legs, small eyes, and different form and proportions ; a second 

 moult takes place after about a week, but is not accompanied by 

 any very great change of form, though the larva is now curved, 

 less active, and in form like a larva of Scarabaeidae ; when 

 another moult occurs the fourth instar appears as a still more 

 helpless form of larva (Fig. 140, D), which increases rapidly 

 iu size, and when full grown leaves the remains of the egg-pod 



Fig. 140. — Hypermetamorphosis of JSpieauta vittata. North America. (After Riley.) 

 A, Young larva or triungulin ; B, Caraboid instar or second larva ; C, ooarctate 

 larva, or instar between the Scarabaeoid and Scolytoid larva ; D, Searabaeoid larva, 

 from which the Scolytoid, or sixth, instar diilers but little ; E, pupa ; F, imago. 



it has been living on, and forms a small cavity near by ; here it 

 lies on one side motionless, but gradually contracting, till the 

 skin separates and is pushed down to the end of the body, dis- 

 closing a completely helpless creature that has been variously 

 called a semi-pupa, pseudo-pupa, or coarctate larva (Fig. 140, C) ; 

 in this state the winter is passed. In spring the skin of the 

 coarctate larva bursts, and there crawls out of it a sixth instar 

 which resembles the fourth (Fig. 140, D), except in the somewhat 

 reduced size and greater whiteness. It is worthy of remark that 

 the skin it has deserted retains its original form almost intact. 

 In this sixth instar the larva is rather active and burrows about, 



