192 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



Through the efficiency of this nozzk^ $2 per acre was saved in spray- 

 ing a piece of woodland containing 3,018 acres. It is very essential 

 that the operator of this nozzle shall use good judgment in directing 

 the stream, so that the foliage will not be reached by it directly. He 

 should hold it in such a position that the solution will reach the foliage 

 as a mist, for if the force of the stream is apphed directly to the foliage, 

 the greater part of the poison will run off, and not sufficient remain to 

 kill the caterpillars. 



We have secured the best results in spraying woodlands the second 

 year, when the undergrowth is allowed to grow up, and the poison 

 which ordinarily falls on the forest cover is deposited on the under- 

 growth, within easy reach of the caterpillars. These machines are 

 capable of filling through a 23^'2-inch suction hose in five minutes, or 

 even less time, if pushed to their full capacity. In discharging, the 

 average time is twelve to fourteen minutes, and nearly an acre is 

 usually covered wiih. one tank of poison. 



A good comparison between the machines previously used and the 

 one designed by this department is that in filling with the old machines, 

 it took from eighteen to twenty minutes, and discharging was done 

 in from twenty-five- to thirty minutes. The saving of time in this 

 operation is a large item in the work, although it is necessary for the 

 men to be much more active in their movements and there is but very 

 little time to lie idle while the filling process is going on. 



In what is known as the North Shore work, that is, the woodlands 

 in Beverly, Manchester and Gloucester, where between 3,000 and 

 4,000 acres are being cared for, and where we have been fighting 

 the moths systematically for three successive years, there will be 

 from 1,000 to 1,500 acres the coming season that it will not be neces- 

 sary to spray. These colonies will probably need to be sprayed 

 alternate years. 



The work on the shade trees in our state, where the trees on 14,000 

 miles of streets must be treated in suppressing the gypsy and brown- 

 tail moths, is a very large problem in itself. Previously, the trees 

 that were sprayed were climbed, and treated with a mist spray, taking 

 much time and with great expense, but by means of the more modern 

 apparatus used this last season, all of the street trees in several towns 

 and cities were sprayed with the solid stream, which resulted in a large 

 saving of money. It has been often argued that not as good work 

 is done with the solid stream on shade trees as with the mist spray,, 

 but in looking over the results which have been secured, very little 

 difference can be observed. It is our belief that the sohd stream will 

 give as good results as mist spray, except in a few cases where buildings 

 may be temporarily defaced by the poison. Some of the machines are 



