REPORT OF FIELD AGENT, GYPSY MOTH WORK, 121 



in numbers and finally they must spread over the territory oc- 

 cupied by the pest they attack. When these three steps have 

 been accomplished we begin to have real benefit from their 

 work; but all this takes time and the proverb that "a stern^ 

 chase is a long one" applies to insects as well as it does to 

 other things. 



While this increase of beneficial forms is taking place the 

 pest is also increasing and damage is resulting from its work so 

 that it becomes necessary for man to adopt some means of 

 fighting it until such time as the parasites increase sufficiently 

 to do this fighting for him. 



Certain injurious forms may be controlled by one enemy but 

 many require a number for this work, all working together and 

 each doing its share, and it is to this latter class that the gypsy 

 and brown-tail moths belong. It is, therefore, evident that we 

 shall only get control of these pests when we have the various 

 enemies responsible for this control in their native homes well 

 established in this country over the entire area occupied by 

 them. 



The United States Bureau of Entomology has been devoting 

 a large amount of effort, during the last few years, to the study 

 of enemies of the gypsy and brown-tail moths. A considerable 

 number of these has been imported from Europe and estab- 

 lished in this country. The men engaged in this work are now 

 helping along the natural spread of these enemies by collecting 

 them from sections where they have become abundant and lib- 

 erating them in sections to which they have not had time to 

 spread. Five of these enemies are at present established in 

 Maine but such a short time has elapsed since their introduc- 

 tion that it is somewhat early to expect any great benefit from 

 their work, though, of course, every particle of work that they 

 do is of considerable value. The distribution of the parasites 

 over as large a territory as is occupied in Maine by the two 

 pests cannot be accomplished in a short time though already 

 long steps in this direction have been made. It should be 

 clearly borne in mind, however, that this distribution is only 

 the first part of the work. It is the only part of the work that 

 man can attend to as the other steps, increase and spread, are 

 taken care of by the insects themselves and there appears to be 

 no way by which we may speed up the process. 



