114 A MANUAL OF FORESTRY 



Several methods of destroying the caterpillars are employed. 

 During the month just after hatching from the middle of May 

 to the middle of June the trees may be sprayed effectively 

 with arsenate of lead. This spray will not injure the tenderest 

 foliage when diluted with water in the ratio ten pounds to one 

 hundred gallons of water. One method of preventing the cater- 

 pillars from climbing trees is to scrape the bark in a belt around 

 the tree and apply a coating of tanglefoot. The caterpillars can- 

 not cross this band if it is stirred up every week or ten days to 

 keep it sticky. Another kind of band, used as a trap, consists of 

 a strip of common burlap a foot wide which is tied around the 

 trunk with a single string at its middle and about four feet from 

 the ground. The upper part of the burlap is turned down over 

 the twine, thus making a double fold around the tree. The 

 caterpillars eat the foliage in the night, crawl down the tree and 

 conceal themselves on the burlap through the day. Squads of 

 men going through the forest crush them in these hiding places. 

 Burlap bands are being used less and less, due principally to the 

 expense involved. 



Rubbish heaps and all breeding places should be destroyed. 

 An effective method of protecting conifers is to remove all 

 hardwoods, especially those with simple leaves. A number of 

 parasitic insects have been introduced from Europe and set free 

 in Massachusetts, and it is confidently hoped that they will in 

 time obtain the mastery. 



The gipsy moth has spread constantly, year by year, despite 

 all the efforts that have been made to control it. At one time it 

 was nearly under control when unfortunately Massachusetts 

 politics interfered, appropriations for suppressing the insect 

 were cut down and the evil spread unhindered. It now appears 

 throughout eastern and central Massachusetts, through southern 

 Maine and the southern half of New Hampshire, throughout 

 Rhode Island and eastern Connecticut. The United States 

 Department of Agriculture is now cooperating with the various 

 states mentioned in an attempt to suppress this evil, and is laying 

 special emphasis on the introduction of foreign parasites and 

 enemies. 



