REPORT OF THE STATE ENTOMOLOGIST I914 73 



care should be exercised to prevent the escape of the insects during 

 the treatment and possible serious results to the operator, since 

 the sting of this species is very painful. 



The writer has suggested that more valued trees might be pro- 

 tected from attack, to a large extent at least, by spraying the 

 branches with a poison, such as arsenate of lead used at the rate of 

 at least 4 pounds to 50 gallons of water and adding thereto 3 to 4 

 pounds of soap. There would be a fair chance of the insects suc- 

 cumbing to the poison if the application was not sufficiently dis- 

 tasteful to ward off the hornets. 



Elm leaf beetle (Galerucellaluteola Miill.) . The elm 

 leaf beetle continues to be a serious pest of elms, particularly the 

 European varieties, though the damage of the last few years has 

 not been nearly so general as during the preceding decade, partly 

 because of more general and thorough spraying. An interesting 

 development the past season was the discovery by Prof. M. W. 

 Blackman, State College of Forestry, Syracuse, of a well-established 

 local infestation of the elm leaf beetle. Some years ago a few insects 

 were received from Oswego and since then no additional spread 

 has been recorded in that section. It is only a question of time, 

 as has been repeatedly stated in other publications, when this pest 

 will probably become well established and be decidedly injurious 

 in most of the important cities and villages of New York State, 

 aside possibly from some localities lying at high elevations or where 

 climatic conditions are so rigorous as to prevent the pest multi- 

 plying freely. 



In the report for 1 9 1 2 ^ we called attention to the influence adverse 

 weather conditions in mid- June had upon an apparently vigorous 

 generation which threatened serious and widespread injury to the 

 elms. Observations at that time showed that this period of 

 abnormally cool weather came at a time when oviposition should 

 have been at its height. Somewhat similar conditions prevailed in 

 the vicinity of Nassau, at least, last June, and a study of climatic 

 conditions based upon the records of the United States Weather 

 Bureau revealed an interesting correlation between arrest in the 

 development of this insect and unseasonable cool weather. Owing 

 to the fact that more detailed observations were made upon the 

 development of the beetle at Nassau, the weather records for 

 Chatham, less than 10 miles distant and the nearest record- 

 ing station, were utilized. Earlier studies show that under normal 



1 N. Y. State Mus. Bui. 156, p. 



