CANKER WORMS. 791 



as the young leaves appear. Three years later, the same speaker 

 recommended* these poisons at the rate of from eight to twelve 

 ounces in a forty-gallon cask of water. 



In 1896, the writer advisedf spraying the foliage with arsenical 

 poisons and applying to the trunks of the trees bands of cloth, or 

 paper covered with tar or printers' ink, to prevent the females 

 from ascending. Later, tests of various substances were made, 

 and it was found that printers' ink was about as satisfactory as 

 anything that could be obtained for the price. Odds and ends 

 of ink, consisting of various colors left over from job work, are 

 sold under the name of "tree ink" at a lower price than that 

 usually charged for printers' ink, and this is just as good for 

 this purpose. It will harden, however, after a short time, and the 

 writer found that' by mixing with it a non-drying petroleum oil 

 it could be kept longer in a viscid state. The oil could also be 

 applied with a brush to the bands from time to time to keep them 

 in proper condition. Pine tar and a preparation called caterpillar 

 lime caused injury to some small trees, even when applied to a 

 band of tarred paper. This method, of banding trees was 

 described by the writer in a paper read at the Fourteenth Annual 

 Convention of the Association of American Agricultural Colleges 

 and Experiment Stations at New Haven in 1900, and printed 

 in the proceedings.^ 



Since then a substance known as "tree tanglefoot" has been 

 placed upon the market, and though this is a proprietary article, 

 it is difficult to make an3rthing for the price that equals it. It 

 remains sticky for a long time and causes no injury to the tree, 

 even though applied directly to the bark. 



Modern Treatment. 

 We must still advise the same general lines of attack as were 

 recommended years ago, namely, spraying the foliage with 

 arsenical poisons and placing sticky bands around the trunks to 

 prevent the ascent of the wingless females. Different substances 

 can now be used for the purpose. The spraying method is advised 

 in the apple orchard, where spraying is generally practised any- 



* Report Conn. Board of Agriculture for 1881, p. 390. 

 + Report of this station for 1896, p. 235. 



j Bulletin 99, Office of Experiment Stations, U. S. Dept. of Agriculture, 

 p. 160. 



