28 



The amount of money to be expended in this direction would natu- 

 rally vary with the number of trees to be attended to, as well as with 

 the variety and the size of the trees and the geographical location of 

 the city. Even in Brooklyn, however (and this seems to the casual 

 observer to be the most unfortunate of all our Eastern cities from this 

 standpoint), it is within bounds to estimate that the expenditure of. 

 14,000 to 15,000 a year would result in green shade trees the summer 



through. This amount, 

 moreover, will in all proba- 

 bility not need to be an an- 

 nual appropriation. The 

 first cost of a proper spray- 

 ing apparatus will have to 

 be added, but the appara- 

 tus once purchased and 

 thorough work performed 

 for two or three years con- 

 secutively, the probabili- 

 ties are strong that the 

 number of shade-tree in- 

 sects would be reduced to 

 such an extent that a con- 

 siderably smaller annual 

 expenditure would be suf- 

 ficient. 



The question of proper 

 spraying apparatus is a 

 rather serious one, since in 

 this direction a considera- 

 ble amount of money 

 should be expended. A 

 steam apparatus will do the 

 work with much greater 

 yet with a strong, double-acting 

 force pump, which can be operated by a single man, and a tank of 

 100 gallons capacity, mounted upon a strong cart, many large trees 

 can be well sprayed in the course of a day. From such a pump two 

 lines of hose may be run with advantage.^ The working force of such 

 an apparatus should be a horse to draw the cart, a man to drive and do 

 the pumping, and one man to each line of hose. Several such machines 

 have been used with good results in the work of the Gypsy Moth 



^In the Yearbook of this Department forl896will.be found an article by the 

 writer entitled "The use of steam spraying apparatus," to which persons interested 

 in such matters are referred in this connection. 



Fig. 10.— Fall webworm. a, light form of full-grown larva; 

 b, dark form of aame; c, pupa; d, spotted form of moth 

 (compare fig. 9)— all slightly enlarged (original). 



rapidity than a hand pump; and 



