INSECT ATTACKS AND REMEDIES 117 



insects which in one way or another do damage 

 to our trees, and in the present chapter only 

 such as cause serious inconvenience by their 

 attacks will be dealt with, suggestions for pre- 

 ventive measures and the best methods of 

 combating the attacks being given. 



The life-history of an insect must be under- 

 stood before either preventive or remedial 

 measures can be successfully adopted, the most 

 important facts to ascertain being the stage 

 of growth and season of the year at which the 

 greatest damage is inflicted. 



There are four distinct stages in the life of 

 an insect : first, the egg ; second, the grub or 

 caterpillar, usually known as the larva stage ; 

 third, the pupa or dormant stage ; and fourth, 

 the adult stage. It is when the insect is in 

 the second or feeding stage that the greatest 

 damage to trees is brought about, as in the case 

 of the goat and wood leopard moths, though the 

 fully developed insect, as in the pine beetle 

 and weevil, has much to answer for in the 

 destruction of the shoots of several species of 

 coniferous trees. Aphides, such as that on the 

 beech and other trees, have also to be contended 



