MEANS OF SPREAD 41 



in this way that the San Jose scale was brought to the United States, 

 and similar circumstances made possible the introduction of the brown- 

 tail moth. 



Various substances used as packing for manufactured products im- 

 ported from the far corners of the world may harbor threatening insects. 



Fruits, fruit products, or other edibles imported for consumption 

 in the United States may, and often do, introduce injurious species. 



Undoubtedly the majority of the pests thus accidentally introduced 

 fail to become establishes! and never are heard from. But if only an 

 occasional species gains a foothold and nuilti})lies, the results are 

 sufficiently disastrous. 



Finally, it happens sometimes that living specimens are imported 

 for experiment or study, and through accident are allowed to escape. 

 The best-known example of this is found in the gJT^}^ moth, now cost, 

 ing New England millions of dollars in attempted suppression or control. 



