174 OUR INSECT FRIENDS AND FOES 



transformation is taking place. This cocoon is 

 a very remarkable structure. The pupa is con- 

 tained in an elastic, silken case lined with a 

 purplish, metallic varnish ; this is enclosed within 

 another covering of a felt-like substance, reddish 

 in colour and fitting the inner case loosely, so 

 that it is somewhat wrinkled. Outside this is 

 a loose, rough network of coarse threads, mixed 

 up with crickets' feet and skulls, and particles 

 of earth and sand. In this elaborate case the 

 insect rests nine months, passing through 

 wonderful changes from larva to pupa, pupa 

 to nymph, until it finally bursts its bonds and 

 escapes as a perfect insect. It then pushes and 

 bites its way through the sealed gallery and flies 

 off into the sunshine. 



It is a curious fact that as far as can be 

 ascertained, all the Sphex hunt some species of 

 Orthoptera ; Sphex occitanica, an inhabitant of the 

 south of Europe, selects the ephippiger of the 

 vine as her prey, an insect many times larger 

 and heavier than herself. 



Sphex occitanica is really solitary in her habits, 

 and invariably makes her nest in some spot 

 where she is quite by herself, in soft, loose 

 ground under the shelter of a projecting rock 

 or stone, or in an old, crumbling wall. She 

 reverses the methods of Sphex flavipennis, and 

 first catches her prey, then digs her burrow in 

 the nearest available spot. Only one ephippiger 

 is stored in each cell, and the Sphex drags it to her 

 burrow by one of its long, thread-like antennae. 

 Seizing this in her mandibles, she hauls the 

 heavy, paralyzed insect along on its back, 



