THE BROWX-TAIL MOTH. 67 



How to Spray. 



One might suppose that the spraying of a tree or a plant 

 was a simple operation, requiring but a modicum of skill 

 and intelligence. This view doubtless is responsible for a 

 large part of the failures in spraying, for particular care and 

 attention must be given both to the mixing and the appli- 

 cation of the insecticide materials, in order to obtain satis- 

 factory results. 



Assuming that the proper materials in proper quantities 

 have been obtained and mixed according^ to directions, a 

 suitable outfit provided, and the water used carefully 

 strained, the work of spraying may be commenced. 



Where trees are treated, spraying should commence at 

 the top. If the wind is blowing, the work should be car- 

 ried on from the windward side. Often in a breeze of low 

 velocity large trees can be thoroughly sprayed from the 

 windward side alone, the mist being drifted on the air. 



The spray should be applied as a fine mist, never in a 



stream. The dew remains on the leaves ; the rain runs off. 



The same is true of spraying ; a mist adheres, but drops 



run off. The nozzle should have a very small aperture, and, 



if backed by a pump of adequate power, the spray will burst 



forth as a fine mist, which should be allowed to diffuse in 



the air before striking the foliage. Hence it is desirable to 



hold the nozzle a few feet from the leaves to be treated. 



In all cases spraying should cease as soon as the foliage 



begins to drip. 



Spkaying Experiments. 



Numerous experiments with insecticides on brown-tail 

 moth larva?, were carried on at the insectary of the gypsy 

 moth committee. So thoroughly, however, had this field 

 of experimentation been covered in the case of the gypsy 

 moth, that few additional facts of value Avere discovered. 

 Certain field experiments upon the brown-tail luotli cater- 

 pillars are of particular value, however, as showing results 

 obtained under the actual conditions which confront the 

 property owner having infested trees. 



In May, 1898, there were secured for experimental pur- 



