8 
or immune to their insect enemies while others are more attractive 
to them. It is well known that there is a marked difference in the 
individual characteristics of cypress trees in any given locality, and 
especially so in different localities, and that there is also marked differ- 
ence among a large number of trees girdled on the same day or time of 
year in the results obtained. Some will die quickly and dry out rapidly; 
some will remain alive a much longer time, the wood remaining moist 
and becoming discolored; some will yield beautifully grained lumber 
of the highest grade; while others, equally as sound, will yield tough, 
cross-grained, dull lumber of a low grade. These conditions are not 
due entirely to the character of the work of girdling, nor to accident, 
local influences of soil, ete., but largely to variations which produce 
more or less distinct, good and poor natural varieties. Therefore cer- 
tain trees or varieties which prove to be especially attractive to the pin- 
borer, no matter when they are girdled, may be attacked and more or 
less injured. 
The girdled-cypress pin-borer must have moist wood in which to 
excavate its burrows and develop its broods of young and will not 
attack the trees after they have been dead long enough for the wood to 
become dry. It evidently prefers to attack the wood of felled gum and 
cypress. Our observations indicate that living trees felled in April and 
August offer specially attractive conditions for infestation by this species, 
and that it will often begin to enter the wood within a few days after 
the trees are felled. This suggests the utilization of felled trees as traps 
to attract it away from the girdled ones and at the same time facilitate 
the destruction of the broods by placing the logs of the trap trees in 
water after they have become thoroughly infested and before the broods 
of adults begin to emerge and fly. 
To accomplish this the trap trees felled in April must be burned or 
placed in water during the following June and those felled in August 
treated in the same manner in October. 
RECOMMENDATIONS. 
General recommendations for the prevention of insect injury to girdled 
cypress may be briefly stated as follows: 
First.—Conduct the principal girdling operations in March, April, 
October, and November, or either in the former or latter months as may 
seem best from the local conditions and relative value of the product in 
each locality. October-girdled trees should be felled and floated or 
worked up within one year to avoid injury by another class of wood 
borers which attack trees after they have been dead one or more years. 
Second.—In localities where it is known that the insect is abundant 
and injurious, felled trap trees may be provided in March and April, 
and July and August, say, one otherwise worthless gum or cypress trap 
tree for each fifty to seventy trees to be girdled in the same locality. 
