66 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



hide under anything they can see through. Burlap bands should be 

 taken ojff and stored or else changed every year. 



Vice-President G. A. Dean: The next paper will be read by Mr. 

 George G. Becker. 



THE CONTROL OF THE ROUND-HEADED APPLE TREE 



BORER 



By Geo. G. Becker, Fayetteville, Ark. 



The investigations discussed in this paper were carried out at 

 Berry ville, Arkansas, in an orchard which represented as bad an 

 infestation of the Round-Headed Apple Tree Borer as has ever come 

 to the wj'iter's notice. From 50 to 75 per cent of the trees of this 

 eight-year-old orchard had been killed by this insect, though the 

 shallow soil may have been a contributory cause to the death of some 

 of the trees. No trees could be found in the orchard which did not 

 show the work of the borer. 



In 1913, a few over 1,000 one- and two-year-old apples trees were 

 set out in this orchard. Trees were set out five feet in rows and ten 

 feet between the rows. There were 67 trees to a row, and three 

 to four rows to a plot. Plots were set out in alternate middles, so 

 that each would have a vacant middle on either side. White Lead 

 Paint , Sherwin-Williams' Pruning Compound, Screening, and Asphal- 

 tum, in varying combinations with oils, were tried out. Except for 

 the screened trees, all were treated at Fayetteville and tied in bundles 

 of 10 to 13 to insure that the different treatments would be well 

 scattered out over the plots. It was thought that Asphaltum might 

 have different effects on different varieties and, accordingly, all the 

 tests were carried out with three varieties. 



White Lead 



Previous experiments with white lead were conducted by Professor 

 Hayhurst, and the author, in 1911, but our data were not conclusive 

 enough. Accordingly, ninety-nine trees were incorporated in the 

 tests at Berryville. Four per cent, of the trees were infested, this 

 representing a protection of 56.7 per cent. Hayhurst, in 1911, found 

 that beetles confined in a cage with twigs coated with white lead, ate 

 through the paint. It is not unlikely that this would happen in 

 the field. Our experiments on white lead were not continued a second 

 year. From our tests we concluded that : 



1. Trees would have to be retreated each year. 



2. The protection obtained was not commensurate with the cost. 



