DnlYersity of the State of New York Bulletin 



Entered as second-class matter August 2, 1913, at the Post Office at Albany, N. Y., under the 



act of August 24, 1912 



Published fortnightly 



No. 589 ALBANY, N. Y. April 15, 1915 



New York State Museum 



John M. Clarke, Director 

 EpHRAiM Porter Felt, State Entomologist 



Museum Bulletin 175 



29th REPORT^OF THE STATE ENTOMOLOGIST 



1913 



D7' John M. Clarke, Director of the State Museum 



I have the honor to present herewith my report on the injurious 

 and other insects of the State of New York for the year ending 

 September 30, 1913. 



Two leaf feeders attracted general notice the past season, namely, 

 the apple tent caterpillar and the allied forest tent caterpillar. The 

 former, devouring the leaves of many orchard and wild cherry 

 trees, was easily recognized by the large nests in the forks of the 

 limbs. It was particularly injurious in the upper Hudson and 

 Mohawk valleys. The latter pest, distinguished by the somewhat 

 diamond-shaped, silvery white spots down the back, defoliated ex- 

 tensive areas of oak on Long Island, attacked the sugar maples in 

 the upper Hudson valley and stripped poplars in the Adirondacks. 

 The probabilities of such injuries were foreseen last year and timely 

 warnings issued. A number of rare or particularly interesting 

 species have been observed during the year, and brief notes con- 

 cerning a number of them are given in the body of the report. 



Petroleum compounds as insecticides. The serious condition 

 of many sugar maples, following the application of miscible oils in 

 191 1 and similar trouble in several apple orchards in 1912, was 

 followed up the past season by studies of some cases, which, in 

 connection with certain experiments, have resulted in confirming 

 our opinion as to the cause of the trouble. This is a matter of 

 much practical importance, since the injudicious use of these mater- 

 ials may jeopardize the existence of hundreds of valuable shade or 

 fruit trees. The details of this work are given on subsequent pages. 



