FISHERIES, CAME AND FORESTS. 9 



delay and in practice it is very difficult to have the spraying properly done, and then 

 there may be hindrances incident to several days or a week of rain at the time the 

 poison should be applied. 



Not a few wait till the trees show signs of serious injury and then ask for some 

 means of stopping the ravages. Under such conditions, resort may be had to spraying 

 with a larger proportion of poison in order to kill the caterpillars quickly or they may 

 be shaken from the limbs, provided the tree is not too large. The latter means will 

 give a certain amount of relief where practicable and should be supplemented by the 

 use of cotton bands or other means of preventing the ascent of those shaken from 

 the tree. 



In order to spray trees successfully, certain rules must be observed. Apply the 

 poison at the time the insects begin to feed and where they must eat it if the tree is 

 attacked. In the case of this insect and the following, it is best to throw the spray on 

 the under surface of the leaves so far as possible, as the young caterpillars prefer the 

 tender lower epidermis. Do thorough work, that is, try to cover every leaf with the 

 mixture and spray till the tree begins to drip, but no more. The finer the spray, the 

 better, as a more even distribution is ensured. The poisonous mixture must be kept 

 agitated while spraying is in progress. While a power spraying apparatus is the best, 

 good work can be accomplished with hand pumps, but plenty of hose must be supplied 

 as a fine spray can not be thrown far and it is, therefore, usually necessary to do more 

 or less climbing. One pound of Paris green, one pound of quicklime, to 150 gallons 

 of water is a very good spraying mixture for this insect. London purple may be used 

 in place of Paris green, if desired. Though costing a little more, arsenate of lead is 

 probably the best poison for most to use, since it adheres an indefinite time to the 

 foliage, its whiteness renders it easily detected, and it can be applied in large 

 quantities without danger of burning the foliage. It is prepared as follows: Dissolve 

 eleven ounces of acetate of lead (sugar of lead) in four quarts of water in a wooden 

 pail and four ounces of arsenate of soda ($0% purity) in two quarts of water in another 

 wooden pail. As the acetate of lead dissolves rather slowly in cold water, the process 

 can be hastened by using warm water. Pour the resulting solutions into the spraying 

 tank which should contain about eighty gallons of water. This poison may be used in 

 much larger proportions without the slightest danger of burning the foliage. 



Polder Spraying Out/it. In the extended work against insects conducted by 

 certain cities and villages, it has been found necessary to have apparatus that will 

 admit of more rapid work than is possible by hand. This has led to the refitting of 

 retired fire engines and the designing of more or less cumbersome outfits for this 

 purpose. In all cases these makeshifts have been successful, though they are not 

 usually so satisfactory in operation as those specially fitted for the purpose. Probably 



