42 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
Insects of each of these types require somewhat different and rather 
exacting conditions for their attack, and a knowledge of their life 
habits will help to prevent a great deal of injury. 
Fall Cutting 
Bark beetles, pinhole borers, and wood borers require a moist or 
green inner bark, and much damage can be prevented by cutting the 
material early in the fall and seasoning it well through the winter 
under cover and off the ground, so as to have it dry by the time the 
beetles appear in the spring. Early fall is the time to cut wood if it is 
desired that the bark remain tight. Sometimes girdling in the fall, 
especially with conifers, permits effective drying ‘thr ough the winter, 
and the logs can be felled and utilized in the spring without danger of 
insect attack. 
A few borers and many powder-post beetles attack round material 
in the process of seasoning, especially hickory and persimmon to be 
used for manufactured articles. To prevent this, the wood should be 
cut in the fall and seasoned through the period of inactivity of the 
insect, or if cut during the active season, it should be stored under 
imsect pr oof conditions or else utilized promptly. A spray containing 
5 percent of DDT in fuel oil will prevent attack for some time, but is 
recommended only where other methods are not available or where 
the wood must be cut green and held during the period of insect activ- 
ity (St. George 568). 
Introducing Chemicals Into the Sap Stream 
One of the most effective treatments for the preservation of material 
for rustic work is obtained by introducing chemicals into the sap 
stream of the living or freshly cut tree. Several methods of accom- 
plishing this have been devised. One of the simplest, suitable for 
small timber, is to cut the tree off at the base, and, with the top lodged 
against or fastened to another tree, lower the base into a container 
holding the chemical solution. 
A method for larger trees consists of removing a 4-inch ring of bark 
at the base of the tree. Then by using a sharp, wide-set saw or a sharp 
chisel, cut a notch or groove completely around the tree in the middle 
of the strip from which the bark was removed. This notch should be 
from 14 to 1 inch deep. A piece of suitable waterproof material, such 
as rubberized cloth, oilcloth, or old inner tubing is put around the tree 
in the form of a collar open at the top, but carefully tacked or tied at 
the bottom immediately below the groove. A ring of asphalt cement 
or heavy cup grease beneath the tacked edge of the collar helps to make 
it watertight. The joint where the ends of the collar meet is likewi ise 
tacked against the tree or pleated in such a manner as to make it water- 
tight. A chemical solution is then poured into this collar. 
“A third but less reliable method consists in felling the tree, leaving 
the crown intact, and removing the bark from 6 to 8 inches of the butt 
and stretching over this a length of inner tube with the other end 
turned up and supported to form a container. The chemical solution 
is then poured into the open end of the tube. Conifers can be treated 
at any time of year when the solutions will not freeze, but best results 
are obtained during the active growing season. Hardwoods can be 
treated satisfactorily only w hile in leaf. 
