124 



INSECTA OK HEXAPODA. 



undergo a complete metamorphosis is different to that of th( 

 adult. Fig. 54 shows the digestive tract of the larva of one o: 

 the Daddy Long-legs (Tipula), which will he seen to be of quib 

 a different type to that given in fig. 34. There are consider 

 able differences in the digestive tract of insects. "We shal 

 observe much variation in the length of larval life when study 

 ing this group : some larvfe live only a few days ; others, at 

 the Wireworm, as much as three or four years. Eventuallj 

 the " full-feed" state is reached, and the larva ceases to feed 

 it is then ready to assume the next stage — namely, the pupa, 

 chrysalis, or nymph. Prior to entering this stage the krvj 

 either enters the ground and forms a cell in the earth, or spins 



— P 



Fio. 52. — PUP.E OF Insects. 



A, Puparia of Dipteron ; P, contained pupa, 

 butterfly. 



i>, Pup.i of moth ; c, chrysalis ol 



a silken cocoon, or finds some shelter in which to pupate. 

 Typically the pupal stage is a period of rest, no food being 

 taken. The pupal skin shows the general outline of the insecl 

 — legs, antennae, wings, Szc, being clearly defined (fig. 52, b). 

 Chrysalis is the term generally used in Butterflies, which are 

 pale-coloured and more or less angular (c). In Flies, and some 

 Hymenoptera, the pupa is found in the old larval skin, whicl 

 hardens and forms a brown case, called the puparinm — the 

 "flax-seed " stage of the Hessian Fly (a, i.) In some diptera tlie 

 pup® are spiny (fig. 53). During this pupal period the majoritj 

 of the larval organs are broken down mto a granular soft mass 



