was effectual iu killing the beetles. It was alsostated thatn previous 

 application of the same poison may have aided the second applica- 

 tion in the destruction of the beetles. 



Arsenate of lead was used in preference to Paris green because it 

 can be used in any desired strength without injury to the foliage. 

 Arsenate of lead is a new insecticide and has not yet appeared in the 

 market, but the Gypsy INIoth Committee purchased it from the firm 

 of Johnson & Shaw, India Wharf, Boston, in large quantities for 

 nine cents a pound. 



Next iu importance to the killing of the beetles is the killing of the 

 larvae, as they appear two or three weeks after the unfolding of the 

 leaves. For this purpose Paris green, at the rate of one pound to 

 100 or 150 gallons of water, should be applied in a spray. Both 

 sides of the leaves should be covered since the larvae feed on both 

 surfaces, eating only the outer tissue. The beetles, on the contrary, 

 devour tlie entire sulistance of the leaf. In spraying either with 

 arsenate of lead or Paris green, small trees may be treated with an 

 ordinary hand pump. P^or larger ones the same pump ma}' be used 

 aided by a piece of hose. One man climbs about in the trees apply- 

 ing the spray to the different limbs, while a man on the ground or 

 in a wagon works the pump. Steam pumps will prove an advantage 

 where spraying is to be dorte on a large scale and on large trees. 

 The mixture should be kept well stirred to prevent settling. Any 

 insects escaping the effects of the poison should be subjected to the 

 treatment recommended for killing pupae. I should have added, 

 however, that where the pest is abundant it will be necessary to treat 

 the entire surface of ihe ground beneath the tree, since, as has been 

 mentioned, a part of the insects drop directly to the ground, and to 

 destroy these the ground should be thoroughly sprayed with kerosene 

 ennilsion diluted about four times. 



Although Prof. Fernald has i)reviously published the method of 

 preparing kerosene emulsion we add it here. The substances 

 required are water, two quarts ; common bar soap, one fourth of a 

 pound ; kerosene four quarts. The water is heated to boiling, the 

 soap being dissolved in it meantime, and while still very hot the 

 kerosene is added and with a force pun)p the nozzle of which is 

 directed back into the mixture, the whole is churned for about five 

 minutes, or until it is emulsified (jelly-like when cold). If well 

 prepared this emulsion may be kept for a long time or it may be used 

 at once. For ordinary spraying on foliage it should be diluted with 



