1 66 OUR INSECT FRIENDS AND FOES 



nourishment. To store live caterpillars in the 

 cell would be equally fatal to the larva, which, 

 even if it were not trampled to death by the 

 imprisoned insects, would be quite incapable of 

 attacking lively food The problem the parent 

 wasp has to face, therefore, is how to provide fresh 

 (i.e. living) food that will at the same time be 

 incapable of harming her larvae. This difficulty 

 she overcomes by piercing the nerve centres 

 of her prey with her sting, so that the insect 

 becomes paralyzed. While the active life is 

 destroyed, vegetative life still exists, so that the 

 insects remain fresh until the young Odynerus 

 is ready for its first meal, and yet is incapable 

 of doing it any harm. 



Another species of Odynerus forms its 

 burrow in the dry twigs of the brier, which 

 it hollows out and divides into a varying number 

 of cells, with a kind of cement composed of 

 earth mixed with tiny stones. As each cell is 

 completed the wasp stores it with provisions, 

 deposits an egg, and seals it with the cement. 

 The most curious fact in connexion with this 

 species is that the egg that is last laid is the 

 first one to hatch out, and the larva makes its 

 escape from the cell, leaving the way clear for 

 the next insect to emerge; and so, in regular 

 order, the eggs hatch, and the perfect insects 

 come forth, in the reverse order to that in which 

 they were laid. 



Other solitary wasps make holes for the 

 reception of their eggs in sandy banks or 

 decayed wood, while a few species construct 

 regular little nests of earth. Vespa coarctata, 



