CANKER WORMS. 789 



comes up out of the ground in the fall as well as winter. Mr. 

 Lyman has found this out by observation. To more effectually 

 defend his trees from the ravages of this pest, Mr. Lyman has 

 used the so-called 'Tree-protector/ which is designed to pre- 

 vent the progress of the insect up the tree. It was a little instru- 

 ment like a tent, held away from the tree by a wire, having its 

 outer edge like an umbrella, with smooth strips of isinglass pro- 

 jecting from the edge; the design of which was this, that if 

 the insects could crawl to the edge they could get no further on 

 account of the slippery foothold they would have. But the con- 

 clusion from the application of these tree-protectors was this, 

 that they were good for nothing, and the canker worm ascended 

 the tree just as well after their application as before. He had 

 tried next the experiment of ploughing his orchards. This had 

 the effect to diminish the number of worms during one season 

 upon his apple trees in an old orchard where the experiment was 

 tried. The ploughing ought to be followed by an application of 

 bonedust." 

 Further recommendations wqre also made at this meeting:* 

 "Professor Brewer said that the Professor of Zoology in the 

 Sheffield Scientific School had been investigating the subject of 

 the different pests of our trees, and especially the history of the 

 canker worm, as it appears upon the elm trees about New Haven. 

 Whether this variety of the worm is the same as that infesting 

 the apple tree, the Professor was not certain, but in this they are 

 alike, they strip the tree of foliage. The variety of worm infest- 

 ing our elm trees attains its growth between the first and seventh 

 of June. It is a common thing to say that they leave about the 

 tenth of June. When they have attained their growth upon the 

 tree, they leave and go down into the ground to go through with 

 their second stage of development there, and as has been said, 

 they come out of the ground in the fall. Three-fourths of our 

 people believe that if they attempt to protect their trees against 

 the ravages of this worm, that it is sufficient if the attempt is 

 made in the spring. It is not so. These worms may come out dur- 

 ing the warm days of winter, and also in the spring. The females 

 .cannot get up the trees without crawling, for they are not pro- 

 vided with wings. 



* Report Conn. Board of Agriculture for 1866, p. 85. 



