PROC. ENT. soc. WASH., VOL. 22, NO. 9, DEC., 1920 229 



a period of ten days. During this time adults were most nu- 

 merous and the notes most shrill. 



The results of these records show that the adults began to sing 

 when the temperature ranged from (>() (if) F. At no time did 

 they sing when the temperature was below (50 F. During two 

 successive nights when the temperature ranged from (52-74 F., 

 it is believed that the concerts were continuous both nights. 

 The writer was awake many times those nights and concerts 

 of considerable volume could be heard, resembling those in the 

 middle of the day. Both Dr. F. C. Craighead and Mr. S. A. 

 Rohwer had similar experiences those nights, therefore, it seems 

 probable that the song was continuous both nights. On the 

 night of June third an attempt was made to start a concert by 

 false alarm. About two o'clock a male was caught. It imme- 

 diately began to sing. Upon being released it crawled away 

 continuing to sing. The note aroused others about, and one by 

 one it was taken up until the whole neighborhood seemed to be 

 one continuous concert. This lasted about five minutes. Grad- 

 ually the song subsided and all was quiet once again. The tem- 

 perature at the time of the concert was (>5 F. 



Relation of Phenological Events in Plants and Cicada. 



The relation of phenological events in plants and cicada may 

 serve as an index as to when the various stages of cicada activity 

 should appear. The following plant records were selected from 

 those taken about Falls Church, Va., and vicinity by Mr. S. A. 

 Rohwer and the writer. Trees representing the range for the species 

 were selected when possible as well as those which were more 

 common and widely distributed. 



Phenological Table. 



a normal g buds swelling 



Buds h swelling h opening 



c opening i first out 



Flowers / half out 



d unfolding k full 



Leaves e first full grown / fading 



/ falling m falling 



n out 



Catkins o flowers opening 

 p pollen falling 



