THE SI REX GIG AS. m 



Whether it has any popular name I do not know, but I have 

 never been able to discover one, although I have shown speci- 

 mens of the insect in many parts of England. 



This is the more extraordinary, because it is really a splendid 

 creature, nearly as large as a hornet, having wide wings, a 

 bright yellow and black body, and a long firm ovipositor, so that 

 from the head to the end of the ovipositor it measures an inch 

 and three quarters in length. So unobservant, however, is the 

 general public, that nine-tenths of those to whom I showed it 

 declared that it was a wasp, and the remainder thought it to be 

 a hornet. 



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 wood, and drilling holes 

 of a tolerably regular form. Towards the end of its larval 

 existence it works its way to the exterior of the trunk, and 

 there awaits its final change, so that when it assumes its perfect 

 form it has only to push itself out of the hole, and so finds itself 

 in the wide world. The insects may often be seen on the trunks 

 of the trees, clinging to the bark close to the hole out of which 

 they have emerged. 



The Lepidoptera number among their ranks some of the most 

 destructive wood-boring insects that inhabit this country. 

 There is, perhaps, no insect which makes so large or so rami- 



