70 FRUIT CULTURE. 



sucking the juices and causing wart-like excres- 

 cences. Often, as the lice mature, they crawl 

 up the trunk and are known as the woolly aphis. 

 Should a tree appear sickly without cause, its 

 roots should be examined, and if found warty, 

 scalding-hot water may be applied without in- 

 jury. Professor Riley suggests also the use of 

 the kerosene emulsion applied to the roots. 



The Oyster-Shell Bark Louse is a very com- 

 mon and troublesome insect, often completely 

 covering the trunks and branches and greatly di- 

 minishing the vigor of the trees. These minute 

 scales, about one sixth of an inch long, cover 

 sometimes a hundred eggs, which hatch in May 

 and June ; remaining for several days under 

 the shelter of the scales, but scattering over the 

 tree as the weather becomes warmer. They are 

 scarcely visible, being only one hundredth of an 

 inch long ; but being so numerous and subsist- 

 ing upon the sap of the tree by inserting their 

 sharp beaks, they cause serious injury. 



Rubbing the trunks and limbs with potash 

 water, washing-soda, or the kerosene emulsion, 

 at the time the Iarva3 are hatching and before 

 they disperse, will easily destroy them. 



To clear the scales at other seasons, when they 

 are hard and dry, will require firmer rubbing, 

 with a stiff brush and potash water. Syringing 

 with kerosene may also prove serviceable. 



