xiv THE GYPSY MOTH. 



do is to find the outside line, even if we don't do any more than 

 that in one season. The old commissioners claim that they have 

 found it ; our first business should be to verify that. 



Professor Shaler. Did they make a map ? 



Mr. Sessions. I think not. 



Mr. ScuDDER. How do they know the moth wasn't blown fifty 

 miles away by a storm ? 



Professor Shaler. It may have been ; but it is a strong point 

 in our favor that after the creature has been twenty years on the 

 scene it still has a tolerably distinct periphery. 



Professor Riley. That is what I have based my recommenda- 

 tion to exterminate it on. I should not like to see the attempt 

 abandoned, but my remarks have all been made with a view of 

 economizing means and time in one effective effort to exterminate 

 it. All these other measures will come in if we have to deal with 

 the pest as a permanent thing among us. As a mere State meas- 

 ure, with a view to not having the unenviable reputation of having 

 given a pest to the rest of the country or done nothing to prevent 

 its spread, Massachusetts has an excellent opportunity of showing 

 what may be done by intelligent, concentrated effort. All other 

 means are puerile as compared with destruction by the arsenicals. 

 All other means are now abandoned in fighting the canker-worm, 

 the codling moth and some other insects, and intelligent spraying 

 at the proper time has come to be looked upon as the most efficient 

 means of protection against these insects. My idea is that what 

 you ought to do is to employ a sufficient force of intelligent per- 

 sons to scour that whole region in the month of June, and indicate 

 every plant that has a brood upon it. 



Professor Shaler. Suppose you had a hundred persons search- 

 ing at the same time, what general instructions could you give 

 them in determining what trees were infested ? 



Professor Riley. The insect is gregarious, and therefore con- 

 spicuous. There is no reason why intelligent search should not 

 detect it, even on the highest trees. 



Professor Shaler. How much time could you reckon on hav- 

 ing for your search after the creature came out ? 



Professor Riley. I should say you could count on ten days 

 after it was hatched. Its gregarious nature makes that feasi- 

 ble. 



Professor Shaler. How much time is there before it begins to 

 spin? 



Professor Riley. I believe it takes three or four weeks. 

 Professor Fernald. I think it highly desirable to make the 

 attempt to stamp it out. I don't know that it can be done, but it 



