11 



Soaps. — Various soaps were also tried, and of these the whale-oil-soap emulsion 

 gave the best results, many of the scales being killed. The whale-oil soap gave good 

 results also, but not equal to the emulsion. 



Kerosene emulsion. — Kerosene emulsion was also tried, and this proved of more 

 value than the whale-oil-soap emulsion, but not so effective as the lime, salt, and 

 sulphur wash. 



Li7ne. — Quick slaked lime, 1^ pounds to 1 gallon of water, proved very effective 

 applied as a winter wash, and equaled the results obtained by the lime, salt, and 

 sulphur. 



Kerosene lime. — This was also tried, but did not prove superior to the kerosene emul- 

 sion, and therefore is not to be preferred to it. 



Prof. T. B. vSymons,'* as a result of tests of sprays upon the oyster- 

 shell scale on shade trees in 1906, concludes: 



That maple trees infested with the oyster-shell scale can be treated both in the fall 

 and early spring with the lime-sulphur and salt wash with satisfactory results as 

 regards controlling the pest, and without injury to the trees. 



That where one application is made these tests showed the fall treatment to be 

 preferable. It is the writer's belief, however, that when the wash is applied thoroughly 

 in early spring equally good or even better results can be obtained. 



The Duke of Bedford and Spencer U. Pickering* report results 

 of detailed experiments with various washes in the destruction of 

 the eggs of this insect, and found that a 3 per cent caustic soda wash 

 gave 100 per cent efficiency in killing the eggs. A 2.5 per cent 

 caustic soda wash with soap also gave excellent results, hut diffi- 

 culty was experienced in handling the wash on account of its becom- 

 ing semisolid. Results of tests of other washes are presented, as 

 caustic soda and potash, paraffin emulsion, emulsion soda washes, 

 emulsions mth lime, lime-sulphur soda washes, etc. 



Concerning the scurfy scale, Mr. J. S. Houser'= states: 



That the lime-sulphur wash applied during the winter is effective, as are also con- 

 tact sprays applied at hatching time. 



The same author (1 c), in speaking of the oyster-shell scale, states: 



The lime-sulphur wash is undoubtedly the control method to be used against this 

 scale, but in the author's experience, it has proven somewhat of a disappointment. 

 From observations made upon hundreds of trees and shrubs, sprayed with a mixture 

 made by experienced men and applied thoroughly, it is apparent that only when con- 

 ditions are the most favorable are the results following its use satisfactory. A slight 

 dampness, such as a light fog at the time of application, a somewhat weakened spraying 

 mixture, an extra case of infestation, where several scales are piled upon one another, 

 a temperature below 32 degrees— any of these unfavorable conditions is suflScient to 

 give poor results. 



Prof. R. A. Cooley'' presents results of extensive tests of sprays for 

 the destruction of the ovster-shell scale: (1) As against the eggs dur- 



a Bui. Ill, Md. Agr. Exp. Sta., 1906. 

 b 8th Rep. Woburn Exp. Fruit Farm, p. 33. 1908. 

 cBul. 194, Ohio Agr. Exp. Sta., 1908. 

 djourn. Econ. Ent., vol. 3, p. 57, 1910. 

 [Cir. 121] 



