116 ANNUAL REPORT OF THE Ofif. Doc. 



Lime-snlfiir Solution (Home-boiled, Concentrated). Slack (iO 

 pounds of high grade lime, adding 125 pounds of line sulfur as 

 described above, and boil in 50 gallons of water for one hour. If 

 necessary add water to make up for any evaporation; strain and 

 store in closed vessels until needed or in open vessels, keeping the 

 solution covered with a thin film of oil. When ready to spray dilute 

 one part with 7 or 8 parts of water, or to specific gravity, as shown 

 by Hydrometer test, of 1.04 to 1.03. 



Lime-sulfur solution (Commercial Concentrated). Many manu- 

 facturers are placing upon the market ready-made Concentrated 

 Lime-sulfur Solutions, and these are found satisfactory and about 

 as efl'ective as the Home-boiled Solution. They should be diluted, 

 as a rule, by adding to one quart of the Ccmcentrated Mixture 7 or 8 

 of water, or to specific gravitv, as shown by Hydrometer test, of 1.04 

 to 1.03. 



Whale Oil. Soap, two pounds, dissolved in one gallon of water, 

 applied as a spray or wash. 



Common Kerosene Oil or Crude petroleum, emulsified, and used 

 not stronger than 30 per cent, for peach and plum trees, and not 

 more than 50 per cent, for apple and pear. (Apply only on dormant 

 trees). All spraying should be thorough, reaching the tips of all 

 twigs, and applied at any time when tree« are dormant. 



H. A. SUEFACE, 

 Economic Zoologist. 



DEPARTMENT OF AGRICULTURE— DIVISION OF ZOOLOGY 

 THE OYSTER-SHELL SCALE AND SCURFY SCALE 



These scale insects differ from the San Jose in the fact that 

 they lay eggs and, die shortly after laying, while the San Jos6 bears 

 living young during a continuous period of some weeks. They also 

 differ conspicuously in appearance. The San Jose scale is to be 

 recognized by its circular shape, and small tip or cone in the exact 

 center. The female of the Scurfy and Oyster-shell scales are about 

 one-eighth of an inch in length, while the males of each species are 

 smaller. The outer shell of the Scurfy scale is whitish, or ashy in 

 color, and oval or fan-shaped, while the covering of the Oyster-shell 

 is dark gray, or about the color of the bark, and the shape is, of 

 course, that of the shell of the oyster, from which it takes its name. 

 The male is smaller, and not so much curved as the female. 



The eggs of the Scurfy scale are purple, as are, also, the young 

 and the bodies of the parents. The eggs of the Oyster-shell are 

 pearly white, as are the young and the fleshy bodies of the insects 

 themselves. These, of course, are only to be seen on raising the 

 shell of each species. Both Oyster-shell and Scurfy have tAvo broods 

 or generations jier year in Pennsylvania. The eggs for one brood 

 are laid in the fall and hatch during the following May, and the 

 eggs for the next generation are laid about the last of July, and 

 hatch in August. With each species the male dies before the eggs 

 are laid, and the female immediately thereafter. The young hatch 

 nearly all at one time, and crawl over the bark a few days before 



