150 INJURIOUS INSECTS 



and kill the eggs without injury to the tree, especially 

 while the sap of the tree is inactive. Hence the Bark- 

 louse can only be successfully fought at the time the eggs 

 are hatching, and the young lice are crawling over the 

 limbs. The time of year in which this occurs, are the 

 last days of May and the first days of June, but without 

 close scrutiny they will not be observed, as they appear 

 like very minute, white, moving specks. "While the 

 young larvae are thus crawling over the tree, they are so 

 tender that they can be readily destroyed by simply 

 scrubbing the limbs with a stiff brush. 



With regard to washes to be used with a syringe, the 

 late Dr. Jno. Kennicott used one pound of Sal. Soda, to 

 one gallon of water with good effect; Mr. E. GL Mygatt, 

 of Eichmond, McHenry County, Illinois, has experi- 

 mented with this insect for over twenty years, with the 

 following result: Brine (2 quarts salt to 8 of water), kills 

 the lice, but also the foliage and fruit. Tobacco- water 

 (strong decoction), neither injures the foliage nor affects 

 the lice. Weak Lye, while it kills the lice, will also some- 

 what affect the leaves. Lime-water kills about half the 

 lice, and affects the leaves a little. Finally, a decoction 

 of Quassia, though well known to be effectual for the 

 common Plant-lice, has no effect on these Coccids. In 

 short, we have abundant proof that neither Tobacco- 

 water, nor strong Alkaline washes, have any effect on the 

 young lice, though a strong solution of soap will kill 

 them, and my experience the past season, with Cresylic 

 Acid soap in other directions, leads me to strongly 

 recommend it for this purpose. It will sometimes be nec- 

 essary to repeat the wash, as the lice do not all hatch out 

 the same day, though the period of hatching seldom 

 extends over three days. 



From the foregoing it is obvious that Bark -lice can 

 only be successfully fought during three or four days of 

 the year; how absurd and ridiculous then, are all the 



