The Peach-Tree Borer. 237 



vate and feed the trees, and we believe the borers can be controlled 

 more successfnlly and much easier in such an orchard. 



Our experiments. — During the past live years we have conducted 

 the most extensive and scientific series of experiments ever attempted. 

 An experimental orchai'd of 400 peach trees was set for the sole 

 purpose of testing the so-called " remedies." The details of the 

 plan and extent of these experiments are discussed on p. 201. We 

 thoroughly tested about 25 representative methods for combating 

 the peach-tree borer. 



Yulnerahle stage of the insect. — The insect is open to successful 

 attack only in its larva or borer stage and in its pupa stage ; the 

 pupae are reached only by searching for the cocoons and destroying 

 them. 



Destructive Measures. 



Of the destructive or killing methods recommended, the '"''freezing''* 

 method (p. 206) and the use of carhon hisiilphide (p. 207) are unsuc- 

 cessful and unsafe. Boiling water and similar methods (p. 206) 

 have been successfully employed, but they are impracticable on a 

 large scale and may injure or kill the trees. 



The " digging-out " method. — The " digging-out " method (p. 208) 

 is the only thoroughly successful and safe way of killing the peach- 

 tree borer. This method is expensive in time and labor, but our 

 experience leads us to believe that any other equally as successful 

 method will cost just as much. To make it a success, the " digging 

 out " should be thoroughly done, not only on every tree in the 

 orchard, but also on all " old relics" of peach trees in the immediate 

 neighborhood. A half-dozen such " old relics " left untreated near 

 by served to thoroughly re-stock our orchard with borers every 

 year, so that our "digging-out" method, although practiced 

 thoroughly each year, never reduced tlie numbers of the borers 

 below the danger limit (p. 204). This is a very important factor in 

 the success of the " digging-out " method. Under certam millennial 

 conditions, mentioned on p. 209, we believe the numbers of borers 

 could be reduced to the minimum in an orchard by this method 

 alone. Practically every peach-grower, who makes any pretensions 

 of fighting the borers, digs them out at least once a year. Many 

 then apply some wash or other device, but curiously enough, they 



