28 NEW YORK STATE MUSEUM 



thej come through channels whose authenticity can not be 

 doubted. . 



RE3IEDIES FOR ASSOCIATED INSECTS 



As the elm bark-louse belongs to that large order of insects, 

 the Hemiptera, which take food only by suction through a fine 

 proboscis from the underlying tissues, it is easily seen that a 

 poison applied externally to the tree, as for example paris green, 

 would have no effect on the insect. The best remedy is found 

 in the use of one of the contact insecticides, preferably kerosene 

 emulsion or whale oil soap solution, which should be sprayed on 

 the under surface of infested limbs and foliage, at the time the 

 tender young are appearing. Kerosene emulsion may be pre- 

 pared by dissolving one half pound of hard soap in one gallon of 

 boiling water and while yet hot add two gallons of kerosene and 

 emulsify thoroughly by passing it rapidly through a force pump 

 until it is white and has a creamy consistency. For the young, 

 one part of this emulsion to ten parts of water should be effective, 

 the whale oil soap solution may be used in the same manner if 

 one pound of the soap be dissolved in four gallons of water. If 

 desired these preparations could be applied in the autumn after 

 the leaves have dropped, but the solutions should be about four 

 times stronger. Small trees may be cleaned by the use of a 

 stiff brush, which might be made more effective by dipping it in 

 one of the above solutions from time to time. 



Preventive measures are of much more importance against 

 borers than any remedies that can be applied. The trees should 

 be kept in as vigorous a condition as possible and careful watch 

 maintained for the first signs of boring, which is indicated by the 

 detached grains of wood popularly termed ^ sawdust.' When 

 indications of their presence are found the larvae should be dug 

 out if possible. A badly infested tree should be cut down and 

 burned in order to prevent the (development of the insects and 

 the adults making their way to other trees. 



