104 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



No. 39. — A duplicate of experiment 17 tried on 200 trees ; pure whitewash 

 was applied as a second treatment. 



Emulsion applied April 21, 190S; whitewash applied September 1, 1908. 



No. J/O. — Placed pieces of branches as traps in trees of small orchard to see 

 if beetles would settle on them. 



No. .'/l. — One-half barrel kerosene emulsion used instead of water to make a 

 good stiff whitewash, applying with broom to plat of 200 or 300 trees. 



First application made May 4, 190S; second application, July 9, 1908. 



No. .'i2. — One gallon of chlorouaptholeum added to every barrel of white- 

 wash used. Whitewash made as thick as possible and applied with a broom 

 to plat of about 200 trees. 



First application. May 6, 1908 ; second application, July 9, 1908. 



No. -'i3. — One gallon of Avenarius carbolineum added to each barrel of white- 

 wash used : whitewash made as thick as possible and applied with a broom to a 

 plat of about 200 trees. 



All fertilizer used in above experiments was of the following 

 formula : 



Per cent. 



Phosphoric acid 8 



Nitrogen 5 



Potash 2 



All trees fertilized made a growth of rich green foliage and the 

 trees looked healthy, yet many of them were again attacked by the 

 beetles. 



RESULTS OF EXPERIMENTS. 



The first 6 experiments seem to show that whitewash acts as a re- 

 pellent, not affecting the beetles once they are in the bark, but if the 

 trees are kept well coated the beetles do not seem to attack the white- 

 washed parts. The addition of fertilizer to the trees causes a strong 

 flow of sap which, exuding through the burrows, seems to repel the 

 beetles. The treatments given in Nos. 7, 8, and 9 seemed to have no 

 effect whatever. In experiments 10, 11, and 12 the beetles in the tree 

 at the time of application appeared to be killed, but the mixture did 

 not act as a repellent and beetles settled on the trees again in a short 

 while. Experiments 13, 14, 15, IG, and 17 were more promising, and 

 two applications a season would undoubtedly keep the beetles down. 

 The expense of these experiments, however, makes them impracti- 

 cable as tried here. In experiment No. 18 all beetles attacking the 

 trees at the time of application were killed, and others did not settle 

 on the trees during the entire season. 



The cost of the materials used in this experiment, however, makes 

 the treatment impracticable. Experiments 19, 20, and 21 had no 

 effect whatever, neither killing the beetles in the trees nor repelling 

 others. In experiment 22 all trees treated were killed. Experiments 

 23, 24, and 25 gave very good residts, the whitewash sticking well and 

 the beetles not attacking the trees until long after the whitewash had 

 fallen off. Experiments 26, 27, and 28 seemed to have had very little 

 effect on the beetles in the bark and did not repel later attacks. Ex- 



