98 



INSECTS 



and large jaws are useless and they enter what is known 

 as the "Carabidoid" stage in which they resemble the 

 larvae of ground beetles. Continued good feeding re- 

 sults in a further reduction of parts and the third instar 

 is even more grub-like and therefore termed the "Scar- 

 abidoid" stage, during which it exhausts its food sup- 

 ply, — either the egg-pod or the stored material in the 



Fig. 42. — Development of a blister beetle: a, grasshopper egg pod with tri- 

 ungulin at // b, a few grasshopper eggs; c, triungulin; d, carabidoid larva; e, 

 scarabidoid larva. 



bee cell. Then the outer skin hardens, the larva loses 

 shape and enters the coarctate stage in which it lies 

 dormant until the period when the adult is due to 

 appear. When this comes, the hardened larval skin 

 is shed and the true pupa, of the ordinary beetle type, 

 appears. When the proper hour arrives, as if at the 

 striking of a clock, the transformation to the adult 

 is completed and the blister beetles emerge, ready to 

 feed and propagate. And now the story changes, for 

 while we can have only words of praise for those larvae 



