168 OUR INSECT FRIENDS AND FOES 



sufficiently to prefer to work in the vicinity of 

 those members of her own tribe who are en- 

 gaged in the same task as herself. 



Having chosen her site, the Sphex works 

 away with a will, biting at the soil with her 

 sharp mandibles, and raking the loose sand away 

 with her claw-like tarsi, emitting all the time a 

 high-pitched humming note, while her wings 

 vibrate in a perfect frenzy of industry. As the 

 tunnel gets longer the Sphex disappears within 

 it, and little spurts of sand may be seen coming 

 out of the entrance as the insect pushes out the 

 loose soil behind her with her hind feet, in much 

 the same way as a mole does when burrowing in 

 the ground. Every now and then the Sphex 

 emerges to dust her wings, or to take a short 

 rest on an adjacent flower-head in the sun ; then, 

 with renewed vigour, she sets to work again on 

 her self-imposed task. So rapidly does the 

 Sphex work that her excavations are generally 

 complete in a few short hours ; then, after a 

 critical inspection of her burrow, and a few final 

 touches, she sets off in search of prey. The 

 game that S.flavipennis seeks is no helpless, soft- 

 bodied larvae, such as the Odynerus captures, 

 but a large cricket, possessing a pair of pincer- 

 like jaws capable of biting and tearing its assail- 

 ant, and formidable, club-like hind legs with which 

 to kick and bruise. It is, moreover, considerably 

 bigger than the courageous Sphex, who, never- 

 theless, attacks the cricket with extraordinary 

 daring and ferocity. The aim of the dauntless 

 Sphex is to turn the cricket over on its back, 

 and this, after a terrific struggle, she generally 



