466 BOARD OF AGRICULTUEE. [Pub. Doc. 



peared to be directly due, however, to drastic treatment at 

 the hands of the gardener, rather than to any after-eflects of 

 the scraping. From 1893 to 1899, inclusive, 19,304 trees 

 were scraped in the gypsy moth work, and no case of 

 injury from the process has been noted, while the great 

 majority of the trees scraped were benefited. A close watch 

 was kept also on the scraping done by owners of orchards. 

 These people in many cases scraped their trees so severely 

 that only the inner bai'k and cambium were left on the 

 trunks, which appeared quite white in contrast with un- 

 scraped trees. But in most cases the work seemed to bene- 

 fit the trees, and in no case could any resultant injury be 

 seen. This is much more than can be truthfully said of 

 pruning as generally practised. 



Scraping trees has long been practised by foresters having 

 charge of valuable shade trees, as a means of stimulating 

 them to repel the attacks of bark beetles. 



This operation is often used, conjointly with "heading 

 back," to reinvigorate old trees, and usually with good re- 

 sults. The bark may be softened at the same time b}^ a 

 good wash of soap suds. To facilitate the healing of a par- 

 ticular Avound, local treatment may be worth trying. It was 

 reported to me in 1899 that the raupenleim or insect lime 

 used on some of the" larger trees in Maiden was injuring the 

 trunks. They were reported as bulging where the lime 

 had been applied. In applying this material to a tree, the 

 outer l)ark was first scraped oil' the trunk in such a manner 

 as to form a smooth belt around it. The insect lime was 

 then plastered on to the smooth surface, forming, when 

 finished, a ring of soft, oily substance around the trunk, 

 which Avould remain viscid for several months. 



If the tree was bark bound, and the scraping knife went a 

 little deeper than was neccssar}- for the purpose of merely 

 smoothing the bark, the thinning of the bark, together with 

 the action of the lime as a softener and lubricant, were 

 sufficient to lessen the pressure of the bark on the trunk, 

 which would account for a greater wood growth here than 

 elsewhere. 



This is precisely what had occurred. In from three to 



