GRASSHOPPERS AND OTHER INJURIOUS INSECTS OF 1911 AND 1912. 59 



3. It is difficult to detect an injury of this kind until too late 

 to use a remedy- 



4. A tree near a number of infested trees is quite sure to be 

 infested although no outward sign of injury may be noted. Strip- 

 ping off the bark is the only means of detection. 



5. When once the grubs are at work in sufficient numbers, 

 nothing can be done to save the tree. 



6. As soon as detected that the tree is doomed, it should be 

 cut down and burned together with the stump. 



7. With some of the borers like the Two-lined Chestnut 

 Borer, stripping the bark from the trunks and limbs would answer 

 the purpose just as well as burning. 



8. The felled trees instead of being burned may be cut into 

 lengths and stored in closed basements where beetles cannot escape 

 in the spring to lay eggs on other trees. 



9. Valuable healthy trees in the vicinity of infested trees 

 should, during the months when the beetles are flying, be protected 

 by some repellant wash. This wash must have good sticking quali- 

 ties and act in such a way that insects will not alight upon such 

 a treated tree to lay eggs. As the important insects mentioned 

 fly around during the last of May, June and the first part of July, it 

 is at this period that the wash placed on these trees should retain 

 its active qualities. These materials may be put on with a brush 

 but it would be easier and simpler to apply them with a spray 

 pump. 



10. Some of the repellent washes that are recommended to 

 be used are the following: Iron sulphide, ordinary whitewash, 

 whitewash to which has been added one per cent of crude carbolic 

 acid, and government whitewash. When one does not care to 

 disfigure a tree in using the whitewash, lamp black may be added. 



Iron sulphide is a fungicide and not an insecticide, but its stick- 

 ing qualities, disagreeable odor and dark color make it valuable as 

 a repellent wash. 



11. As said in the beginning, co-operation among all concerned 

 is essential. Individual work is practically useless. It is suggested 

 that in the cities, park boards, and other boards or commissioners 

 having charge of shade trees be given absolute authority to enter 

 upon private property within the city limits and take the proper 

 steps against infested trees. 



