166 NEW YORK STATE MUSEUM 



and pear leaves with wash. 4. Plum foliage was injured very 

 slightly by wash 5, and number 6 -burned tips of peach leaves to 

 a slight extent but did not injure pear foliage. Washes 1, 2, 3 

 and 4 adhered well, 5 and 6 more so, 6 in particular being thickly 

 incrusted on limbs and foliage. Wash 1 killed 85$ of the scale, 

 and there was a marked contrast between sprayed and unsprayed 

 branches. Wash 2 had no effect on the scale, while 4 killed 30$. 

 The latter was boiled longer and this may account for its greater 

 effectiveness. Variation in intervals between preparation and 

 application appeared to have no effect on the adhesive or insecti- 

 cidal qualities of these washes. 



Summary. A mechanical 20$ crude petroleum emulsion was 

 applied in early July, two seasons in succession, to peachtrees 

 without causing much injury beyond dropping some of the foliage 

 where it was the thickest. It undoubtedly destroys a large 

 amount of scale and seriously checks breeding, yet we hesitate 

 to do more than state what it has accomplished. It is perhaps 

 the best thing that can be used where a very bad infestation is 

 discovered in midsummer. 



A whale oil soap solution, 1 pound to 8 or 10 gallons ; a kerosene 

 emulsion (standard formula diluted with 6 to 10 parts of water), 

 or a 15 or 20$ mechanical kerosene emulsion can be used in 

 midsummer for checking the San Jos^ scale, but none of these 

 materials can be relied on to kill much more than the crawling 

 young, and breeding is soon almost as bad as before the appli- 

 cation unless treatments are frequent. 



Our experiments with lime-sulfur combinations for a summer 

 wash have not been as successful as was hoped, though 25 pounds 

 of lime, 20 pounds of sulfur to 240 gallons of water with a 15 

 minute boil killed a large percentage of the scales on an old 

 appletree in early September without materially injuring the 

 foliage. It is barely possible that a combination of about this 

 strengih can be used with beneficial results, but nothing of the 

 kind can be recommended till further experiments have tested 

 its practicability. 



