April, '12] BURGESS: SHADE TREE PESTS 175 



tomary to treat with creosote such gypsy moth egg clusters as can be 

 found. Control work for the leopard moth is far more difficult and 

 it appears evident that if the trees are kept in a vigorous condition, 

 that injury from the European elm bark beetle must be reduced to a 

 minimum. 



The cities and tovra surrounding Boston expend large sums of 

 money each year to care for their shade trees. It is not uncommon 

 for a town to expend SI, 000 or more annually for elm leaf beetle 

 spraying in addition to the cost of controlling the gypsy moth and the 

 brown-tail moth and for other shade tree work. 



Two of the most striking examples that can be found in the region 

 mentioned and which illustrate the interest that is manifested in 

 work of this kind is in the treatment of the trees on historic Boston 

 Common and those in the city of Cambridge, which lies just across 

 the Charles river. 



On the Common are many large elms and maples, some of which 

 tower eighty to ninety feet into the air. 0-v\dng to the strong public 

 sentiment in favor of the preservation of these historic trees, special 

 care has been taken from time to time to protect them from insect 

 injury, but in spite of this, considerable damage has resulted, especially 

 in the last few years, from the attacks of the leopard moth. 



In order to replenish the soil fertility so as to give the trees every 

 possible opportunity to survive, the earth has been removed to a 

 depth of from one to three feet, depending upon the quality which was 

 found. The poor soil has been hauled aw^ay and rich loam, mixed 

 with lime, bone meal, and manure substituted. Already thirteen 

 acres have been treated in this way and the complete project contem- 

 plates similar treatment of thirty acres during the next few years at 

 the expenditure of about $200,000. 



In addition to this, an entomologist has been emploj'ed to look 

 after the insect problem and Mr. J. W. Chapman has had charge of 

 this work for a year or more. He has made a special study of the 

 leopard moth and the European elm bark beetle and has recently 

 pubhshed an excellent bulletin containing the results of his investiga- 

 tions. 



The greatest problem in connection ^ith the insect work has been 

 to control the leopard moth and Mr. Chapman has succeeded in reduc- 

 ing the injury to some extent, but the task involves much difficult 

 and tedious w^ork and its ultimate success is impossible to forecast 

 at the present time. 



In Cambridge, w^hich has been termed the city of elms, much injury 

 has resulted from the work of the elm leaf beetle. For several years 

 many trees have been defoliated by this insect, as a result of poor 



