202 SEVENTH REPORT OF THE FOREST, FISH AND GAME COMMISSION. 



Various mixtures have been tried — Paris green, London purple, and arsenate of 

 lead — each with good effect. Prof. Felt, State EntomoJogist, recommends the fol- 

 lowing preparation as an effective one against the ravages of leaf-devouring species: 

 Dissolve eleven ounces of acetate of lead (sugar of lead) in four quarts of water in 

 a wooden pail, and four ounces of arsenate of soda (50^^ purity) in two quarts of 

 water in another wooden pail. As the acetate of lead dissolves rather slowly in cold 

 water, the process can be hastened by using warm water. Pour the resulting solu- 

 tion into the spraying tank, which should contain about eighty gallons of water. 

 Where a contact insecticide becomes necessary, as in the case with sucking or biting 

 insects, aphids, plant lice, scale pests, etc., he advises the use of this emulsion : Dis- 

 solve one-half pound of hard soap in one gallon of boiling water, and, while still 

 hot, add two gallons of kerosene; emulsify by passing rapidly through a force pump 

 till it assumes a uniform creamy consistency and the oil does not separate. Dilute 

 this with ten parts of water before using. In limestone regions use the sour milk 

 emulsion, composed of one gallon of sour milk and two gallons of kerosene ; emul- 

 sify and dilute as described before. 



The cost of spraying depends necessarily on the extent of the work — • the larger 

 the number of trees, the less will be the average expense. In 1898 the cost of spray- 

 ing Elms in Albany was about fifteen cents per treefor each application ; and in 

 1900, with a more expensive apparatus and men working under the eight-hour law, 

 it cost twenty-two cents. In Troy, trees were sprayed by contract at twenty-three 

 cents for each spraying, a much higher price being charged for single or scattering 

 trees. In New Brunswick, N. J., a contract for the season, including treatment as 

 often as needed, was made at one dollar per tree. The expense, whatever it may 

 be, is insignificant as compared with the value of the trees. 



A simple and effective check on certain insects — the white-marked tussock moth 

 for instance — consists in destroying the egg masses. In 1894 the school children 

 of Rochester, N. Y., stimulated by liberal cash prizes, gathered 8,800,200 cocoons of 

 this insect, and thoroughly eradicated the pest in that locality. Of the successful 

 scholars, 65 received a $10 gold piece each, while others received smaller awards. 

 The prizes, which were offered and paid by the Genesee Valley Forestry Associa- 

 tion, amounted to much more than was expected; but the money was well expended 

 and cheerfully paid, as the city saved its shade trees and secured immunity from 

 further ravages of a destructive insect. 



The limits of this article will hardly permit of a description of the various insects 

 and borers that infest our shade trees; or a recital of the many formulas for insecti- 

 cides which have proved effective in checking their ravages. 



