FOURTlillXTIf JXXr.lL MEETING. 133 



in various strcnQ;ths and also in combination with crude petro- 

 leum. A number of tests with hydrocyanic acid gas were also 

 made. Experiments were conducted the same year by Pro- 

 fessor Lowe, with various strengths of kerosene oil. Experi- 

 ments along similar lines were continued the following year, 

 and in 1902 both of the above named parties began a series 

 of tests with lime-sulphur washes, which have been continued 

 till the present time. 



The above summary has been given for the purpose of ex- 

 plaining the development of this work in the northeastern 

 United States. Previous to 1895 there had been practically 

 no need of winter washes of one kind or another, and as a 

 consequence eastern entomologists were unfamiliar with these 

 materials and could hardly be blamed for accepting as con- 

 clusive the eastern experiments mentioned above, which were 

 conducted by parties more or less familiar with the behavior 

 of these materials in the West. 



Whale oil soap solutions are undoubtedly efifective when 

 thoroughly applied, though they are too expensive for general 

 use in orchards, and as a consequence a cheaper material had 

 to be found, even though careful men were able to obtain very 

 satisfactory results when only a pound and a quarter of soap 

 was used to a gallon. 



Fumigation with hydrocyanic acid gas was at this time the 

 onlv other treatment known to be efficacious in destroying the 

 scale. A great many experiments were tried for the purpose 

 of demonstrating its value in this climate, and considerable 

 time and thought given to devising a practical apparatus for 

 use upon moderate sized or even larger trees. The great cost 

 of enclosing large trees with a gas-tight structure has pre- 

 vented the general adoption of this method by orchardists and 

 restricted its employment to the nurserymen. This method 

 of treatment is undoubtedly our best safe-guard against the 

 further dissemination of this pest, and even then the fumiga- 

 tion must be very thorough or insects may escape the deadly 

 fumes. Generally speaking, we prefer to recommend this 

 measure as a means of insuring safety rather than to indorse 

 its employment in the freeing of nursery stock from scale 

 known to be present. In this connection it mav be well to 

 allude very briefly to our system of nursery inspection, which 



