274 FRUIT INSECTS 



sulfur at ordinary winter strength to which has been added an 

 excess of lime. 



Various kinds of wrappers for the prevention of the entrance 

 of the borers were formerly much used, but are now generally 

 discarded because of their tendency to render the bark tender. 

 Where conditions are such as to warrant their use wrappers 

 made of several layers of newspapers or cheap brown paper 

 tied tightly around the trunk and extending from the roots to 

 a height of about two feet give fairly good protection at a mini- 

 mum of expense and labor. Tarred paper is frequently recom- 

 mended, but it is no more effective than the cheaper newspaper 

 wrappers. Tobacco stems wound tightly around the trunk 

 from the roots to a little above the surface of the ground kept 

 out from two thirds to five sixths of the borers in the New York 

 experiment mentioned above. They are cheaply obtained at 

 cigar factories and are worthy of further trial. Wrappers to 

 do the most good should be in place and kept intact through- 

 out the egg-laying period, which varies in different parts of the 

 country, as stated abov(\ To be most effective washes and 

 wrappers should always be used in combination with the digging- 

 out and mounding methods. 



Wire cages loosely encircling the trunk and tightly closed at 

 the top with cotton were strongly recommended in Missouri 

 some years ago, but further experiments have shown that they 

 are practically worthless, although theoretically they should 

 give perfect protection. Actually more borers were found in 

 trees fitted with these devices than in those entirely unprotected. 



References 



N. .J. Agr. Exp. Sta. Bull. 128. 1898. 

 Cornell Agr. Exp. Sta. Bull. 176. 1899. 

 Cornell Agr. Exp. Sta. Bull. 192. 1901. 

 Georgia Agr. Exp. Sta. Bull. 73. 1906. 

 N. J. Agr. Exp. Sta. Bull. 235. 1911. 



