542 Report of the Entomologists. 



the same date as in Experiment No. 8. Nineteen trees were 

 used, as follows: Five eleven-year-old peach trees, variety Early 

 Rivers; four bearino- pluin trees, variety Reine Claude; two cherry 

 trees, a variety of sour cherry just come into bearing; and eight 

 dwarf Bartlett pear trees not yet of bearing age. 



June 4, one of the peach trees had lost all of its foliage and 

 was apparently dead. Both of the cherry trees looked sickly. 

 The foliage was abnormally light in (;olor and the young cherries 

 were ripening prematurely. The foliage of the plum trees had 

 also begun to turn a lighter shade. A few days later the deu- 

 drolene was scraped off from the cherry and plupi trees to prevent 

 further injury. The jiear trees did not seem to suffer any in- 

 jury. Before fall, however, four of the peach trees were dead. 



Summary and Conclusions. 



When exposed to the weather, a slight crust forms on the den- 

 drolene, but it is not heavy enough to support insects as large 

 as the female canker worm moth. 



No injury is caused in one season to full-grown apple trees by 

 the application of this insecticide, either in bands around the 

 trunk or to the entire trunk. When applied during the growing 

 season to the trunks of young bearing plum, cherry and peach 

 trees in such a manner as to cover the entire trunk, there is 

 much danger of serious injury to the trees. 



