Sucking Insects 141 



showing variations from ten cents to ten dollars per tree.^ 

 Of the trees of Springfield, Mass., 16,000 were sprayed at 

 an average cost of twenty- ,.;4.^ 

 nine cents. This cost was 

 reduced in Saratoga, for 

 5,667 trees of twenty to 

 eighty feet in height, to 

 seventeen and a quarter 



, J • -n 11 vu Fig. ^i;. — "Vermoral" sprav nozzle. 



cents, and m Brooklyn, with ^^ ^ - 



steam apparatus for 8,712 trees, to twelve cents per tree, 

 and this may be still further reduced by perfecting the 

 apparatus and the organization. With hand apparatus, 

 the cost for spraying trees up to forty feet in height may be 

 as many cents as there are feet in height, but after that it 

 increases more rapidly with the height. 



It is hardly practicable for each tree owner in a city, town, 

 or village to provide himself with a spraying outfit, but 

 every city, town, or even village can afford to supply an 

 apparatus which would serve the entire community and, 

 either at public expense or by cooperative effort, all trees 

 could be sprayed cheaply, and in a few years the insect 

 question would be easy to take care of, if there is also co- 

 operation in exterminating those insects which cannot be 

 readily reached by poison. 



Sucking Insects. As stated before, these poisons are 

 effective mainly with those biting insects which de\'our 

 their food. They are not effective, or only partially so, 

 . with scale-insects, plant-lice, borers, as well as Curculios, 

 ' chinch-bugs, etc., and all other kinds that suck the sap of 

 the plants. These are best reached by a kerosene or soap 

 emulsion, also applied by spraying, but in such a manner 

 that the insect is struck, for they act by contact. 



'Reported by A. H. Kirkland in The Shade-tree Insect Problem. 



