24 BULLETIN NO. 1, DIVISION OF ENTOMOLOGY. 
suppose that parasites had accumulated from the surrounding trees 
where the scale-insects had been destroyed, the parasites having lived. 
Parasites are not always present on infested trees. It must be borne 
in mind that the results given are from only one application of murvite. 
In every instance it is probable that some scales escaped the spray. 
Where no living insects or eggs were found, it is probable that the 
work was finished by the parasites. 
The results shown in the special experiments were verified by the 
general results in the field. Over two thousand trees were the sub- 
jects of experiments, and these were of all sizes, but principally from 
four to ten years old. Some trees, as shown by the table, would be 
entirely cleared of insects, whilst others, apparently alike inevery way, 
would have a quantity of living eggs, and sometimes, but rarely, living 
larvee. 
The results to the tree itself are important. Those in Nos. 1 and 2 
have been repeatedly verified; the quick destruction of the insects be- 
ing followed by the quick recovery of the tree. In every instance where 
there was life below the infested portion, the dying of the branches has 
been arrested at the moribund wood. From the limbs that were thickly 
encrusted with scales, defoliated, the twigs already dead, in a few days 
after spraying with murvite young shoots pushed out through the 
loosely adhering seales and grew rapidly. 
Many trees have quite regained their former size, after losing three- 
fourths of their branches early in the spring by scale-insect, and this 
recovery has been without manuring. 
In some cases the slow recovery of a tree is caused by the rust mite, 
pointed out to me by Mr. Hubbard during his visit; the surface of leaves 
in such cases being rendered almost useless to the tree, it must make 
new foliage. In some cases what are known here as white ants are at 
the roots and retard recovery. 
In all cases where everything else is favorable to growth except the 
insect, the tree makes unusually rapid growth after the application of 
murvite in sufficient strength to destroy the insect. Different strengths 
of solution give different immediate results. The record of results 
shown by the microscope in Nos. 8 to 17 is of the actual count made from 
the scales remaining on the trees; a large number had been blown off. 
The examination on October 25 shows very remarkable final results, 
and suggests that weak solutions of murvite at short intervals may be 
adopted with success. In all cases further applications of a moderately 
strong solution should follow the first. It must be noted that these - 
experiments were made with unusual care, every possible means being 
used to reach every part of the tree and thoroughly wet it. I find 
it very difficult to train laborers to do this without much unnecessary 
waste. 
The ravages of the rust mite on the leaves and fruit of the orange are 
next in importance to the scale-insect. Being almost invisible to the ' 
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