INSECTS INJURIOUS TO THE ORANGE. 419 



destroy life by contact, or produce death when inhaled 

 through the breathing-pores; for since these insects draw 

 their food from beneath the surface of the tissues, the appli- 

 cation of any poison which requires to be eaten with the food 

 to produce its effects is not likely to be of much service. 



Scale-insects on the bark of the trunk or limbs of trees 

 may be removed mechanically by using a stiff brush, either 

 with or without the use of an insecticide. Those on the 

 smaller twigs and leaves can only be reached by spraying 

 some suitable liquid on the trees. Alkaline washes seem to 

 have successfully stood the test of practical experiment, and 

 are used with good results by many of the leading fruit- 

 growers on the Pacific coast and in Florida. 



A solution of concentrated lye or commercial potash, or its 

 equivalent in lye made directly from wood-ashes, appears to 

 be equally effective. 



One bushel of good wood-ashes will produce about four 

 pounds of potash ; hence, in making alkaline washes for trees, 

 this estimate may be acted on where concentrated lye cannot 

 be conveniently procured. To obtain the potash in solution, 

 place a bushel of ashes in a keg or barrel having a tap or 

 spigot near the bottom. Press them firmly and evenly down, 

 and lay a small piece of board on the ashes, so that the water, 

 when poured on them, shall not disturb their surface. Pour 

 hot water on the board, so that it may spread and soak evenly 

 through the ashes, using a sufficient quantity to saturate them 

 thoroughly. Allow it to stand twenty-four hours, then draw 

 off the lye at the tap, adding more water to displace that held 

 by the ashes, until eight gallons are obtained. As the first 

 portion of the liquid which comes off will be much stronger 

 than the last, agitate the solution so that it may be thoroughly 

 mixed. Each gallon may then be estimated to contain half a 

 pound of commercial potash. 



For cleansing orange or other Citrus trees from scale-insects, 

 take one pound of concentrated lye to three gallons of water, 

 or one and a quarter pounds of commercial potash, or its 



