160 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



of the United States it would not be necessary or desirable to spray 

 with poison so late in the season and this being the case the poison 

 which would remain on the fruit from ordinary spraying, would be 

 much less than the amounts recorded in the paper presented. 



President W. D. Hunter: The next paper will be by Mr. G. D. 

 Shafer on, "How Contact Insecticides Kill." 



HOW CONTACT INSECTICIDES KILL 



By G. D. Shafer, Lansing, Mich. 

 (Withdrawn for publication elsehere.) 



President W. D. Hunter: As the amount of time remaining is 

 very limited it has been suggested that Dr. Felt's paper be read and 

 discussed and that the remaining papers be placed on the program 

 for the next session. If there is no objection we now will listen to the 

 paper by Dr. Felt, entitled, "Injuries Following the Application of 

 Petroleum and Petroleum Products to Dormant Trees." 



INJURIES FOLLOWING THE APPLICATION OF PETROLEUM 

 OR PETROLEUM PRODUCTS TO DORMANT TREES 



(Abstract) 

 By E. P. Felt, Albany, N. Y. 



Attention was called in a summary manner to earlier injuries in 

 New York state by petroleum or mechanical emulsions of the same. 

 More recent damage following the application of miscible oils to hard 

 maples and apple trees was briefly described. The conclusions reached 

 were as follows: 



The use of oils or oil preparations on dormant trees has been fol- 

 lowed in several cases by severe injury. 



Trees, as living organisms, respond to climatic and cultural condi- 

 tions and, as a consequence, their power of resisting penetration 

 and injury by oils undoubtedly varies with the season and probably 

 from year to year. 



Since certain weather conditions promote injury by oils, it appears 

 impossible to be certain that deleterious effects may not follow spraying 

 trees with an oil or oil preparation. 



Fall treatment with an oil appears to be more hazardous than 

 spring applications. 



Other things being equal, we believe there is less danger of pene- 

 tration by oil and a consequent injury if the applications are made 



