[FLETCHER | PRESIDENTIAL ADDRESS ? 11 
was the finest illustration possible of the value of the department to give 
the people aid in time of distress, and the distress was very great indeed.” 
Mr. William F. Channing, of Passadena, wrote, two years later: + We 
owe to the Agricultural Department the rescue of our orange culture by 
the introduction of the Australian Lady-bird, Vedalia cardinalis. The 
White Seales were incrusting our orange-trees with a hideous leprosy. 
They spread with wonderful rapidity, and would have made citrus growth 
on the whole North American continent impossible within a few years. 
It took the Vedalia, when introduced, only a few weeks absolutely to 
clean out the White Scale. The deliverance was more like a miracle than 
anything I have ever seen. In the spring of 1889 I had abandoned my 
young Washington Navel orange-trees as irrecoverable. Those same trees 
bore from two to three boxes of oranges apiece at the end of the season 
(or winter and spring of 1890). The consequence of the deliverance is 
that many hundreds of thousands of orange-trees of the finest varieties 
have been set out in southern California this last spring.” 
In other words, the victory over the scale was complete and will 
practically remain so. The history of the introduction of this pest, its 
spread for upwards of twenty years and the discouragement which 
resulted, the numerous experiments which were made to overcome the 
Insect and its final reduction to unimportant numbers by means of an 
apparently insignificant little beetle imported for the purpose from 
Australia, will always remain one of the most interesting stories in the 
records of practical entomology.” The results of all this may be sum- 
marized as follows :—An experiment, the cost of which was limited to 
$2.000, has rendered the cultivation of oranges, lemons, limes and other 
citrus fruits possible in California, whereas but for this experiment the 
whole of that important and lucrative industry would inevitably have 
been entirely wiped out, thus involving the loss of hundreds of thousands 
of dollars. The same satisfactory results have also followed the intro- 
duction of the Vedalia into Cape Colony and Egypt. 
CONTROLLING BY VEGETABLE PARASITES. 
Closely allied with the subject of the utilization of the insect parasites 
of insects is the propagation and distribution, when required, of the con- 
tagious diseases of insects of a bacterial or fungous nature. In this dir- 
ection careful investigations and extensive experiments have been carried 
on in Kansas by Prof. Snow, in Illinois by Prof. Forbes, and in Massa- 
chusetts by Prof. Roland Thaxter. 
Prof. Forbes has recorded (‘Insect Life,’ V., p. 68) that several of the 
plant parasites of insect feed greedily on very common substances, and 
may consequently be kept in stock or made to multiply on occasion with 
enormous rapidity, and so scattered broadcast where and when most 
