New York Agricultural Experiment Station. 433 



Table VI.- 



Activities of Hibernating Brood of Pear Psylla and Conditions 

 of Trees During the Spring of 1912. 



have been little discussed and for this reason efforts have been 

 made in our work to secure more abundant data concerning the habits 

 of the winter "flies " during the spring months. In 1910 the great 

 spring movement of the "flies" took place on March 26 in western 

 New York and they remained active until a severe rainstorm accom- 

 panied with ice caused them to seek the protection of the bark 

 again. In 1911 the psyllas remained dormant until about April 6, 



28 



