1908.] PUBLIC DOCUMENT- -No. 73. 133 



Although the cost of the work done at Spot Pond constitutes the 

 larger part of the entire expenditure, the amount expended was reduced 

 from that of last year by about two-fifths. There has, however, during 

 the past year been a considerable increase in the number of gypsy 

 moths along the lines of the Sudbury and Cochituate aqueducts in New- 

 ton, Weston, Natick and Framingham. The 220 acres of land about 

 the Weston reservoir and lying along the Weston aqueduct between the 

 reservoir and the terminal chamber were especially infested, and the 

 cost of protecting these lands was more than double the amount ex- 

 pended in the previous year. No gypsy moths have been found upon 

 the property of the Board situated west of the town of Framingham. 



The number of brown-tail moths at the Chestnut Hill reservoir and 

 on other lands in the vicinity of Boston has been greatly decreased, 

 apparently from natural causes. Very large numbers of nests of the 

 brown-tail moths have been destroyed at the Sudbury reservoir, and 

 these nests in considerable and increasing numbers have been destroyed 

 at the Hopkinton reservoir, along the line of the Wachusett aqueduct 

 in Southborough and Northborough, and in the vicinity of the Wachu- 

 sett reservoir in Clinton. 



The methods employed for destroying and preventing the spreading 

 of the moths have been as follows :- 



At Spot Pond the egg clusters of the gypsy moths were painted dur- 

 ing the winter with a mixture of creosote and fuel oil. During the lat- 

 ter part of April and the early part of May tanglefoot was used in 

 large quantities for banding the trees. During June and July the trees 

 on 23 acres of land were sprayed with arsenate of lead. To protect the 

 lands of the Commonwealth along the lines of adjoining properties, 

 where the moths were very prevalent, lines of boards set on edge and 

 smeared with tanglefoot have been effectively used as in the previous 

 year. The trees upon the grounds at Mystic Lake, Mystic pumping 

 station and reservoir and at the Chestnut Hill and Weston reservoirs 

 were treated in a similar manner. Along the line of the aqueducts and 

 at Lake Cochituate the egg clusters of the gypsy moths were painted 

 with creosote, and at Lake Cochituate great numbers of trees were 

 banded with burlap. 



Vast numbers of the caterpillars of both gypsy and brown-tail moths 

 were destroyed along the lines of the Cochituate and Sudbury aque- 

 ducts, at Lake Cochituate, and of the brown-tail moths about the reser- 

 voirs in Framingham, Southborough and Clinton. 



Inasmuch as experience has shown that the absolute suppression of 

 the gypsy moth is very difficult, if not impossible, wherever there is 

 a thick growth of underbrush, considerable work has been done, par- 

 ticularly along the lines of the aqueducts, in cutting away underbrush 

 and undesirable trees. 



The total amount expended for the work on all of the water works 

 lands was $10,700, as against an expenditure of $12,700 the preceding 



