14 REPOKT 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 ^nd 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 



