THE FROTHING HOPPER 179 



Undoubtedly the pouch is lined with a sticky fluid, what- 

 ever its source, and the air comes from without, being 

 enclosed by a liquid film at the moment of the closing of 

 the valve. The different writers who have described the 

 frothing hopper give quite contradictory accounts, and 

 Fabre is the only one whose statements agree with what I 

 have seen. 



Shelter within a mass of foam has become necessary to 

 the grub of the frothing hopper, and it dies if its protect- 

 ing envelope is removed. The skin is so thin that the body 

 soon dries up. It seems probable that the artifice of a 

 covering of froth was adopted in order to defend the 

 insect from its enemies, and the purpose is attained, 

 though not with unfailing success. Predatory insects of 

 the wasp-kind and insect-eating birds have been seen 

 to pick the grubs out of their hiding-places and carry 

 them off. 



Like many other insects of the Hemipterous order, the 

 frothing hopper feeds on the juices of leaves or soft green 

 stems. It is provided with a flexible proboscis well 

 adapted for piercing. When the fresh-hatched grub has 

 found a convenient place of abode upon a green shoot, it 

 drives in its proboscis, and without moving again feeds 

 upon an inexhaustible supply of sap. 



When summer is at its height the frothing hopper under- 

 goes a change of form which almost amounts to transforma- 

 tion. The hind legs of the grub are replaced by a pair of 

 much greater length, which are adapted to leaping, for 

 though the adult insect has wings, it generally moves by 

 leaps. The change takes place within the frothy mass, 

 which hardens externally, and encloses at this time a large 

 empty space. 



When the fully formed insect becomes free, it justifies 

 its name of frothing hopper, for in late summer it hops 

 about the bushes with much agility, taking leaps of several 

 feet when alarmed. The female at last becomes so laden 

 with eggs that she is unable to leap any more. It is said 



