INJURIOUS INSECTS OF 190g AND IQIO. 69 
No aperture was allowed during the spring and summer, on any 
part of these cages, or at the lower edges. They were kept under 
lock and key, and no one but the writer had access to the trees 
within. In this connection it must be remembered that the young 
scale becomes fixed a few hours after birth. It is, therefore, only 
during this very short period that the danger of spreading the pest 
exists in the young stage. During the remainder of the year the 
scales are securely fastened to the tree. In the winter we have torn 
the muslin from the top of the cage, thus exposing the insects to all 
of our weather conditions. In both cages the scales survived the 
winter of 1907-1908, and were so thrifty in the spring that they were 
apparently the cause of the death of the trees in one cage. The scales 
in the cage naturally died after their food supply was cut off by the 
death of the host-plants. The scales in the other cage went into 
winter (1908-1909) in fairly good condition, but were found to be 
dead in the summer of 1909, as were also the trees. 
Suggestions as to Preventive Measures and Methods. 
However faithful inspectors in scale-infested states may be, it is 
evidently quite impossible to completely prevent the exportation of 
every scale insect. Minnesota nurserymen, orchardists and buyers 
of ornamentals from any states south of us (as well as southeast and 
southwest) should look upon all such importations with suspicion. 
According to our present inspection law we are obliged to honor 
certificates issued by inspectors from other states who, as intimated 
above, cannot completely eradicate the scale, however conscientious 
they may be. For that reason we believe it would be wise for our 
citizens, as a means of self-protection, to ask those from whom they 
are purchasing stock to have their order fumigated before shipping. 
This request on the part of purchasers is quite common. In case this 
is not done, a careful examination of the stock should be made upon 
its arrival and in case scale is found, or even if one does not find it, 
fumigation should be resorted to. We are glad to note that this has 
already been done in the case of scions, by one of our progressive 
nurserymen. Not that the scale was found upon scions received by’ 
him, but it was regarded as a good precautionary measure. 
Since the dipping of trees is now looked upon as dangerous, 
fumigation with hydrocyanic acid gas is regarded as by far the best 
-method. The process is as follows: A house or box should be con- 
structed, containing a known number of cubic feet (100 cubic feet, 
