40 SEVENTEENTH Report STATE ENToMOLOoGIST oF MINNESOTA—1918 
be culled. Asa result anything that looks like a cull is usually left in 
the woods even though it may contain a considerable amount of good 
material. 
RECOMMENDATIONS 
So far as protection from ant attack of cedar trees in the woods 
is concerned, nothing can be recommended at the present time. It is 
possible, however, to save an immense amount of merchantable mate- 
rial by closer utilization of ant infested cedar, combined with intelli- 
gent trimming of poles. Since it is possible to tell approximately 
where a pole must be cut to clear it of serious ant injury by simply 
looking for the topmost window, it seems unnecessary for the buy- 
ers to cull so heavily for this defect as is the general rule at present. 
The grading rules regarding this injury should be made more lenient, 
so that a cedar maker can be reasonably certain to receive for a pole 
what it is really worth. Dealers should accept ant poles at their full 
value provided the injury is not such as to weaken the pole. Ii a pole 
shows ant work on no more than 10 per cent of the butt surface, and 
has no windows more than one foot above the butt, the pole should 
not be considered weakened. 
Until something of this sort is done it is certain that the cedar 
makers will continue to leave in the woods many valuable poles and 
much good post material. 
SUMMARY 
1. Large black ants commonly known as carpenter ants are doing con- 
siderable damage to standing white cedar in Minnesota, at least twenty per 
cent of the trees cut showing ant injury on the stump. 
2. The colonies are started in a wound, knot hole, or decayed spot, usually 
near the butt of the tree. 
3. The ants hollow out a nest in the heart of the tree sometimes leaving 
only a thin shell of wood around it, thus seriously weakening the tree at that 
point. 
4. From this nest the ants cut openings to the outside called windows 
and to locate a nest it is only necessary to look for the windows. 
5. Much unavoidable loss is occasioned by ant injury, but there is also an 
immense amount of loss through careless cutting of poles. 
6. Culling heavily for ant injury has meant leaving in the woods any- 
thing that looks suspiciously like a cull. 
7. The grading rules regarding ant injury should be made more lenient so 
as to encourage more careful trimming of ant infested poles. 
