158 NEW YORK STATE MUSEUM 



tion. It affected the washes by making them more or less flaky, 

 increasing the amount of sediment, and if much more had been 

 added it would probably have seriously affected the operation of 

 the pump. This material, if used, must be thoroughly diluted 

 with warm water before being added to a cooler lime-sulfur wash, 

 or it is likely to give trouble by gumming up the apparatus. 



Summary. Our experience and experimental work may be sum- 

 marized briefly, as follows : 



A mechanical 20^ crude petroleum emulsion is a very effective 

 insecticide, and if the pump can be relied on to deliver a constant 

 proportion, there is very little danger of much injury from sev- 

 eral annual early spring applications. There is, however, some 

 doubt as to the ultimate result, and the continued use of this 

 material causes increased thickness and roughness of the bark, if 

 no other injury. 



Early spring applications of whale oil soap solution, even if 

 only 1] pounds be used to a gallon, will control the insect in a 

 very satisfactory manner, provided the spraying is thorough. We 

 are by no means certain that this can be done on large trees, par- 

 ticularly those with rough bark. 



The lime-sulfur combination is steadily gaining favor in the 

 eastern states, and under certain conditions, at least, is fully as 

 effective in checking the scale as either crude petroleum or a whale 

 oil soap solution. Our experiments lead us to believe that 25 

 pounds of lime and 20 pounds of sulfur to 60 gallons of water, are 

 equally as effective as larger amounts, and we believe it to be an 

 advantage to have a little more lime than sulfur. We fail to see 

 any beneficial results from the use of salt in this combination, 

 and therefore have omitted it ; and in our experience, active boil- 

 ing for 30 minutes, if the lime is slaked in hot water and the sulfur 

 added at once, gives just as effective a wash as one which has been 

 boiled for one and one half or two hours. 



In conclusion, the experience of Mr Hart and other up to date 

 fruit growers, has demonstrated not only the possibility but the 

 practicability of keeping this insect in control in an ordinary 

 commercial orchard. Our observations show beyond doubt, that 



