56 Farmers’ Bulletin 1169. 
Prevention of attack.—Once a tree is badly attacked nothing can 
save it and the axe is the best remedy. If this is applied during 
the winter or early spring, before the beetles begin to emerge, to all 
trees or infested branches of a community, and the wood is promptly 
burned, many of the beetles will be destroyed and the rest of the 
Fic. 34.—Elm borer and work: 1, Grub within its burrow; Ja, grub extended; 
2, pupa within its cell just under the bark; 8, burrows of the grub exposed 
by removal of the bark; 4, adult beetle, (IFelt.) 
trees saved. As indicated under “ How destructive,” removal or 
prevention of the agencies causing the primary weakening of the 
trees will go far toward preventing the beetles from inflicting the 
final fatal blow. This preventive work can best be called scientific 
arboriculture, and involves proper nourishment of the tree and its 
protection from injury. 
