80 EI^TOMOLOGICAL SOCIETY OF ONTARIO. 



contrary, passes through five or six generations in the course of a summer, and, as it is 

 purely predaceous, it will, I believe, prove a most useful auxiliary against the Black Scale, 

 especially if brought over without its parasites. 



So far I have spoken only of the insects which have been imported into this country, 

 but some effort has also been made in the opposite direction. Thus we have endeavored 

 (and with some success) to return the service done us by sending to Australia and New 

 Zealand some of our predatory Ooleoptera, some of the Pacific coast parasites of the Cod- 

 ling Moth, and a species of the interesting genus Raphidia, which also preys upon the 

 Codling Moth. 



In 1887 and 1888 the now well-known importation of Vedalia cardinalia from 

 Austi-alia and New Zealand to California, to prey u[)on Icerya purchasi, was successfully 

 carried out. The history of this striking example of the beneficial results that may, in. 

 exceptional cases, flow from intelligent effort in this direction, is now sufficiently well 

 known to American economic entomologists ; but anticipating that we shall have foreign 

 delegates among us, and that our proceedings will be published more widely than usual, it 

 will, perhaps, be wise to give the salient historical facts in the case, even at the risk of 

 some repetition of what has been already published. In doing this the indulgence of the 

 society is craved for the prominence of my own part in the work, rendered necessary by 

 the disposition in some quarters to distort the facts. 



The Fluted Scale, otherwise known as the White or Cottony-cushion Scale (Icerya 

 purchad, Maskell) Fig. 38, is one of the largest species of its family (Coccidse), and up to 

 1888 had done immense injury to the orange groves and to many other trees and shrubs of 



Southern California. From Australia, its original 



^^<==*^ home, it had been imported into New Zealand, South 



'"^^ " / Africa and California, the evidence pointing to its 



/ J introduction into California about 1868, and, probably, 



fe: ' upon Acacia latifolia. 



^ In my annual report as U. S. Entomologist for 



1886, will be found a full characterization of the species 

 (.■ 'ti}\-%^ ^ in all its stases ; but the three characteristics which 



I 



most concern the practical man, and which make it one 

 ^ "^ '■ \ of the most difficult species to contend with, are its 



ability to survive for long periods without food, to 

 . -^ ^ , thrive upon a great variety of plants, and to move 



^^ ^^ '' "'^ about throughout most of its life. 



The injuries of this insect, notwithstanding the 

 efforts to check it, kept on increasing, and some ten 

 years ago I felt that the work of this particular species 

 and of others which seriously affected she fruit-growing 

 interests of Southern California, justified the establish- 

 ment of agencies there. Up to this time no special 

 entomological effort had been made by the Government on behalf of the fruit-growers of 

 the Pacific coast. Through agents stationed, the one at Los Angeles, the other at 

 Alameda, a course of elaborate experiments was undertaken as to the best means of treat- 

 ing the insects aftecting the Orange there, and more particularly this Fluted or Cottony- 

 cushion Scale, During the progress of these investigations, however, the fact impressed 

 itself upon my mind that we had here an excellent opportunity of calling to our aid its 

 own natural enemies, for while there were some doubts as to the origin of Icerya, the 

 question was finally settled to my own satisfaction that it was of Australian origin, 

 and that in its native home it was not a serious pest, but was kept subdued by natural 

 checks. These facts were not positively ascertained without a good deal of correspondence 

 and investigation, involving, in fact, a trip to France, as has been set forth in my published 

 writings upon the subject. 



In my report as U. S. Entomologist for 1886, in an address before the State Board 

 of Horticulture at Riverside, California, in 1887 ; in a paper before the Philosophical 

 Society of Washington in the winter of 1888, and elsewhere, I urged, with all the force at 

 my command, the advisability of endeavoring to introduce the natural enemies which 



