182 



HOMES WITHOUT HANDS. 



tliat it was a wasp, and the remainder thought it to be a hornet. 

 A very reduced figure of the insect is shown in the illustration, 

 and wiU give a good idea of its general form. In size it is ex- 

 ceedingly variable, some specimens being twice as laige as 

 others. 



The Sirex is a terrible destroyer of fir-wood, in some cases 

 riddling a tree so completely with its tunnels that the timber is 

 rendered useless. In a little fir-plantation about two miles from 

 my house, there are a number of dead and dying trees, and 

 almost every tree shows the ravages of this destructive insect. 

 The absence of external holes is no proof that the Sirex has not 

 attacked the tree, for they are only the doors through which the 

 insect has escaped from the tree into the world. 



The mode in which the Sirex carries on its operations is simple 

 enough. 



With the long and powerful ovipositor the mother insect 

 introduces her eggs into the tree, and there leaves them to be 

 hatched. As soon as it has burst from the eggs the young grub 

 begins to burrow into the tree, and to traverse it in all direc- 

 tions, feeding upon the substance of the *rood, and drilling holes 



