THE USE OF INSECT LIME. 129 



wind from the branches of one tree to those of another, ren- 

 dering all precautions useless. 



In banding, all poles, dead trees and other objects which 

 in any way communicate with banded trees must be removed 

 or banded. Where the limbs of trees touch houses, fences, 

 rocks or the earth, they must be so trimmed as to prevent 

 such contact. Unless all such means of communication are 

 cut off, banding will not produce the desired effect. Much 

 discrimination must be used in banding trees in cultivated 

 lands, lest the caterpillars be driven from trees and scattered 

 abroad among shrubbery, weeds or garden crops, where they 

 cannot be so readily dealt with. 



Raupenleim Bands. 



In 1891 Mr. B. F. Fernow, chief of the Division of For- 

 restry of the United States Department of Agriculture, 

 recommended that "raupenleim" or "insect lime," a Ger- 

 man preparation for the protection of trees, be used in this 

 work.* A sample was ordered, but it arrived too late in 

 the season to be experimented with that year. In 1892 

 experiments were made, and later thirteen and one-half tons 

 of the "leim" were ordered and used in banding 40,704 

 trees during that season and the next. The raupenleim used 

 in 1892 was very effectual, but much of the importation of 

 1893 was apparently inferior in quality to that used the 

 previous year, and the results obtained were anything but 

 gratifying. If results similar to those of 1892 can be secured, 

 this material will be of great value for use in this country 

 against such insects as the canker-worms, which pupate in 

 the ground and whose female imagoes are wingless. 



Raupenleim was used in the gypsy-moth work to take the 

 place of the tarred paper bands. The advantages obtained 

 from its use are that when of a good quality and properly 

 placed upon the tree, it will remain soft and viscid for several 

 months, and during that time will prevent the ascent of 

 nearly all larvae and also wingless female imagoes. The sub- 



* Raupenleim, translated literally, would read " caterpillar glue." According to 

 Webster, lime (a viscous substance) is akin to the German word "leim." It is 

 used here in connection with the word insect in much the same sense as it is used 

 in connection with bird as "bird-lime." 



