ANIMALS INTRODUCED FOR SAKE OF UTILITY 263 



Chalcid parasite buried in the noxious Scales. In three years 

 a total of 3,000,000 twigs have been distributed in Argentina 

 alone, and the Commission considers \h2&Prospaltella berlesei 

 has now been so satisfactorily and plentifully established as 

 to check the invasion of the Mulberry Scale. 



So successful have been the results of the introduction of 

 counter-pests in many foreign lands, that sooner or later con- 

 servative Britain, when it has awakened to the value of 

 scientific methods, may be led to forsake its easy policy 

 of laissezfaire, and to add a few benefactors to the host of 

 pernicious insects it has already allowed to be added to the 

 native fauna. In this hope the above illustrations of the 

 value of counter-pests have been inserted here. 



