92 BOARD OF AGRICULTURE. [Pub. Doc. 



to exterminate an insect is to find and introduce parasites; 

 but it should be generally known that parasites do not 

 exterminate an insect pest. It is possible that they may 

 reduce the numbers and keep it from doing harm for" a series 

 of years; but as the insect itself dies oft* its parasites nat- 

 urally die, and sooner or later the insect will come to the 

 front. In Europe, where the parasites of the gypsy moth 

 are numerous, it is still a serious scourge. It is said to have 

 spread through central Europe, Asia, and throughout Japan, 

 and it will undoubtedly be a tremendous scourge here if it 

 is allowed in any way to spread. 



Mr. Lynde. I understand, from what the secretary says, 

 that there is a liability of their being carried on cars if they 

 are carried on teams. 



Mr. Forbush. There is some liability of the insect 

 being carried by rail, but the country in which it is found 

 has communications mostly with Boston, and it is very un- 

 likely that they will be carried any great distance except on 

 people going back and forth. Let us suppose that two 

 caterpillars are carried out on the person of one of these 

 gentlemen here, if he is in the infested territory at the time 

 when caterpillars are crawling. In that case the chances of 

 their both being dropped at the same place are very few. The 

 probability is, of course, that they will be widely separated ; 

 and it is better to have one worm alone in the western part 

 of the State than here, because we are certain it will never 

 produce any progeny there ; but while here it may, because the 

 male will find the female, if within a certain distance. We 

 have followed up many clues outside of this section, where we 

 had reason to suppose they would be carried ; but we have 

 not found them except in the towns right about here. 



Question. Have you entirely exterminated it from any 

 part of the infested district ? 



Mr. Forbush. That is exactly the question I want to 

 answer. I can say that, as far as it is in the power of 

 man to determine, we have exterminated the insect in many 

 different places ; that is, small colonies. I think in every 

 case we have done it by gathering the eggs, and by that 

 alone. We have tried spraying and a good many other 



