PEACH INSECTS 273 



After the removal of the ])orers in the fall there is nothing 

 to be gained by applying washes or wrappers, but many growers 

 believe it pays to make such applications in June before mound- 

 ing the earth around the trunks. At least fifty different kinds 

 of washes havo been suggested for preventing the attacks of 

 the peach-tree borer in the century or more; that American 

 fruit-grow(Ts have })een fighting this pest ; some have been found 

 injurious to the tree and many others practically worthless; 

 most of these have been eliminated so that now only a very 

 few are in common use. In general, washes are less effective 

 than one would expect because it is very difficult to cover the 

 rough bark of the tree trunk thoroughly enough to fill all the 

 minute cracks and crevices through which the young larvae 

 usually gain entrance. Furthermore, the growth of the tree 

 causes the wash to crack, thus exposing a fresh surface to the 

 young borers. Many washes contain a poison, Paris green or 

 arsenate of lead, intended to poison the borers as they gnaw 

 through the protective coat, but they are of doubtful value. 

 The young larvae are very active and will usually be able to find 

 some unprotected crevice before beginning to feed. 



In an extensive series of experiments conducted in New York 

 in 1895-1900 and also in the hands of some commercial growers 

 gas tar as a protective wash has given excellent results, but as 

 others have found it injurious to the trees under certain conditions 

 it should be used with caution. It should not be applied to 

 trees the first year after planting, before they are thoroughly 

 established, nor should it be used in the fall. If applied to 

 healthy trees in the spring while the vegetative growth is active, 

 there is little danger of injury. A wash much used in com- 

 mercial orchards in Georgia consists of 2 quarts soap, J pint 

 crude carbolic acid, 2 ounces Paris green, all mixed in a pail 

 of water, to which enough lime and clay have been added to 

 make a thin paste. In New Jersey a wash is strongly recom- 

 mended composed of 1 pound arsenate of lead in 5 gallons lime- 



