176 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



spraying, or failure to apply the poison early enough in the season. 

 The leopard moth is exceedingly abundant, in this city and is causing 

 enormous injury. Over 1,000 large street trees, chiefly elms, have 

 been removed or marked for removal during the past two years. Many 

 of these were injured to some extent by bad pavement and other con- 

 ditions. Nevertheless, it is a fact that in the adjoining city of Somer- 

 ville, where pavement conditions are very similar and the tree growth 

 is similar enough to that in Cambridge to permit a reasonable com- 

 parison, only a few trees have died each year. The leopard moth is 

 fully as bad in Somerville as in Cambridge, and evidence of its work 

 can be noticed without making a careful examination. The large 

 historic elms in the college yard at Harvard University are for the 

 most part in a dying condition, due entirely to these causes, and al- 

 though an heroic effort was made to save them during the winter of 

 1909 and 1910 by pruning them severely and fertilizing the ground 

 beneath them, it is now evident that most of them will succumb, in 

 fact, some have already been removed. 



In the town of Arlington, which immediately adjoins Cambridge, 

 the street trees are in excellent condition. They have been sprayed 

 systematically and have suffered practically no injury from leaf eating 

 insects. To be sure, the leopard moth is present, and just how much 

 damage it is destined to do is difficult to predict. The -conditions, 

 however, are in striking contrast to those in Cambridge. In a part 

 of Arlington, street trees are less subjected to injury from pavements 

 and this may account in a very slight degree for the differences noted. 

 After all has been said, however, the insect problem is the most impor- 

 tant, for if these pests are controlled the trees will have a fair chance 

 to thrive but if the contrary is the case, their opportunity is exceed- 

 ingly limited. 



This subject brings up the question of the value which may properly 

 be placed upon a well developed shade tree. It is impossible to state 

 this at all definitely, although everyone appreciates the fact that 

 shade trees add to the value of city or country property. If we base 

 the value of a shade tree upon the cost of the small tree and the expense 

 of planting and caring for it until it becomes large enough to give a 

 reasonable amount of shade, we find that the total value is far greater 

 than would be supposed. Undoubtedly this is a very conservative 

 way of determining the value of such trees, as it shows what would be 

 the cost of replacing them, although in addition to this it would be 

 necessary to wait from ten to twenty years or more in order to obtain 

 the result. In several cases tried in court the value of city shade 

 trees has been rated as high as $500 each and this amount has been 

 collected. 



