4 



Paris green is the best arsenical, and may be safely used on elms at the rate of one 

 pound to 100 to 350 gallons of water. If London purple be used, an amount of lime 

 equal to the poison in weight should be added to combine with any free arsenic and 

 prevent scalding of foliage. The liquid should be applied with a strong force pump 

 with a long hose and a nozzle, such as the Vermorel or Nixon, which will make a fine 

 mist-like spray. In spraying for the larvae it is very essential to thoroughly wet 

 the lower side of the leaves, on which they principally feed. In the case of the 

 adults, this is not so necessary, because they eat the entire substance of the leaf, 

 and will get the poison from either side. 



On elms fifteen or twenty feet in height, the treatment can be made from the 

 ground or from a wagon. For larger elms, it will be necessary to climb up into the 

 tree, using a hose 50 to 100 feet long, and directing the spray by this means into the 

 upper branches. By removing the spray tip from a large size Nixon nozzle, so as to 

 get a direct discharge, the upper branches of comparatively tall trees may be 

 reached and sprayed in a more or less satisfactory manner. In the case of very 

 large elms in city parks or streets, the use of stronger apparatus may be advisable, 

 such as a fire engine or steam pump and a larger nozzle, such as a graduating spray 

 tip, capable of throwing either a direct stream or a spray. During spraying the 

 poison should be constantly stirred to prevent it from settling to the bottom of the 

 tank. 



The first effort should be to destroy the beetles and larvae at their earliest appear- 

 ance, to save the trees for the current year. Sometimes, however, larvae in the tops 

 of tall trees will escape, and, whenever from inefficient spraying or neglect they 

 are allowed to reach maturity, a strong effort should be made to destroy the insect 

 when it reaches the ground to transform, and thus limit or prevent damage from 

 the second brood or on the following year. The collection of the larvae for pupa- 

 tion, frequently in enormous numbers immediately about the base of the tree, 

 makes it comparatively easy to destroy them in this situation. This maybe accom- 

 plished either by wetting them with boiling water or with kerosene emulsion, diluted 

 about four times. Frequently they may be collected by hand or shoveled up, and 

 burned or otherwise destroyed. 



Remedial treatment is much simpler in the northern areas of the range of this 

 insect, where it is single-brooded, and becomes more difficult in the southern dis- 

 tricts, where the number of broods is doubled, and the appearance of the insect 

 becomes somewhat irregular, continuing practically throughout the summer. 



C. L. Marlatt, 

 First Assistant Entomologist. 



Approved. 



Chas. W. Dabney, Jr., 



Assistant Secretary. 

 Washington, D. C, May SS, 1895. 



