Insects and Fungi Attacking Trees, Etc. 321 



methods of preventing serious loss from the above pests. 

 The reader is referred to the popular bulletins published 

 by the various experiment-stations often giving illus- 

 trations of destructive insect or fungous pests vdih full 

 treatment for their destruction. If one finds a pest at work 

 and is not famiHar with it, specimens should be sent at once 

 to the entomologists or botanist of the station of his state 

 for identification and advice as to remedies. 



Insecticides 



(Insect-destroyers.) 



Practically there are but very few of the common insecti- 

 cides needed or of much value in the preservation of farm, 

 garden, or ornamental crops, and these are Paris green, 

 arsenate of lead, Pyrethrum powder, hellebore, lime and 

 sulphur solution and soluble oils, whale-oil soap, and tobacco 

 water. The first four are used for the destruction of chewing 

 insects and the others for sucking insects. 



Paris Green is a deadly poison and should be used "with 

 extreme caution, and never be applied in large quantities to 

 crops used as food or be kept in such places as to be accessi- 

 ble to irresponsible persons or children. 



Pure Paris green contains but a small per cent of soluble 

 arsenious acid, and can be used \\'ithout injur\^ upon most 

 plants in sufficient quantities to destroy any insects that 

 feed by biting or chewing the parts. Samples containing 

 more than 4 per cent of soluble arsenious acid should be 

 used with considerable caution. 



Paris green alone can be safely used only at the rate of 

 I pound to 250 or 300 gallons of water. This, however, is 

 a very small quantity, and to enable more to be used lime is 

 added to neutralize the soluble arsenious acid. Two pounds 

 of lime slaked in water and added to 25 gallons of water 

 will enable us to use as much as i pound of Paris green 



