308 



SOILS AND PLANT LIFE 



In these cases, hellebore or pyrethrum (insect powder), 

 may be substituted. 



Those insects which suck, as the plant hce, or aphids, 

 and the melon bugs, push their " beaks " down into the 

 tissue of the leaf or fruit and take out the juices, destroying 

 the plant or a part of it in this way. No poison, applied 

 to the surface of the leaf, wiU affect them. A spray of 



Fig. 141. 



Covriesy Iowa Stale CoUefje. 

 - Spraying an orchard. 



tobacco decoction, lime-sulfur, or kerosene and soap, 

 apphed to the plants, comes in contact with the bodies 

 of the insects and destroys them. The tobacco decoction, 

 which is called nicotine sulfate, or Black Leaf 40, and the 

 lime-sulfur preparation may be purchased at most drug 

 stores. Directions for dilution and apphcation accompany 

 the mixtures. The kerosene and soap mixture, called 

 kerosene emulsion, is made as follows : 



