14 REPORT OF SEARCH FOR ENEMIES OF CITRUS WHITE FLY. 
Albert Koebele was sent by Prof. C. V. Riley, then chief of this office, to 
that country in- search of natural enemies. His discovery of Novius 
cardinalis, its introduction into California in 1889, and its subse- 
quent rapid development and spread soon resulted in such a com- 
plete destruction of the cottony cushion scale that the insect has no 
longer been a factor in citrus production in that State. 
This remarkable work of Novius resulted in a great stimulus 
to the efforts to bring about insect control by means of natural 
enemies and has become an historical event in applied entomology. It 
might be added that the universal success against the cottony cushion 
scale by a single natural enemy has never since been duplicated in the 
case of any other insect pest. From this most successful introduc- 
tion to the present day many more or less successful attempts in the 
utilization of natural enemies have been made. The most exten- 
sive work of its kind ever undertaken is that now being carried on 
under the direction of this bureau in New England against the gipsy 
and brown-tail moths, which are highly destructive to forest, orchard, 
and shade trees in that region. These insects were accidental introduc- 
tions from Europe, and on that continent are preyed upon by numer- 
ous natural enemies. Extended efforts in importing all available 
parasites and predatory insect enemies of these two pests and in 
establishing them in New England have met with marked success. 
Because of these facts and others of a like nature a demand devel- 
oped in Florida for an exploration of foreign countries to discover if 
possible the natural enemies of the white fly. Such exploration had 
been heartily recommended by the various investigators of this bureau 
who had been working on the white fly problem in Florida, and was 
also supported by the Florida Experiment Station and by orange 
growers. The partially effective control by the various fungous 
enemies of the white fly was an additional argument for the introduc- 
tion of the natural insect enemies to supplement the work of these 
beneficial fungi. 
As the result of these demands Congress set aside a special appro- 
priation, in 1910, for the purpose of searching the world to discover 
the native home of the citrus white fly and learning if it was there held 
in check by natural enemies. If natural enemies could be found these 
were to be collected, brought to this country, and, if possible, estab- 
lished in Florida. 
PREPARATIONS FOR THE SEARCH. 
The writer was asked by Dr. Howard, Chief of the Bureau of Ento- 
mology, to undertake the mission of searching for the native home of 
the white fly and of ascertaining if it was anywhere attacked by natural 
enemies other than those already known in Florida. After bringing 
to a satisfactory close an investigation of the use of hydrocyanic-acid 
