212 PROC. ENT. SOC. WASH., VOL. 23, NO. 9, DEC., 1921 



desirability of putting on record a few of his own observations 

 made in the vicinity of the District of Columbia. Both of the 

 articles referred to record nocturnal singing by this cicada; 

 testimony agreeing with the writer's experience, but disagreeing 

 with the statement in our most complete publication 1 on the 

 seventeen-year "locust." During the height of abundance of 

 the insect in the Washington region the nights were very warm 

 especially for the period May 29 to June 4 inclusive. On these 

 dates not only were the insects singing as I retired and when I 

 arose, but whenever I waked at night I did not fail to hear the 

 cicada chorus. Perhaps nocturnal singing occurs only when 

 the temperature surpasses a certain and probably rather high 

 minimum. 



It does not seem that the general ring of cicada music can 

 be produced by the notes one hears made by individual cicadas 

 close at hand. The most common solo note, in my experience, 

 is perhaps the " Pha-r-r-r-aoh " note. To me the first part of 

 it sounds like the distant cry of Fowler's toad; the latter part 

 passes from a cooing to an "o" sound, this phrase descending 

 rapidly both in pitch and volume. The end of the abdomen of 

 the insect is depressed each time these falling notes are given. 



Another common note produced by the cicadas is a clicking 

 sound. It is given rapidly and the end of the abdomen of the 

 insect is depressed with each click; one individual I noted lifted 

 the wings and swiftly depressed them at each emission of the 

 sound. This note is quickly taken up by nearby cicadas and 

 a clicking chorus is soon under way. 



A note that I have not seen described is a zip, zip, z-e-e-e-e- 

 a-a-ah, of quite orthopteran quality. This note also is quickly 

 taken up by a number of individuals and in such a chorus, as 

 well as in the case of the clicking note, a considerable degree of 

 synchronism is apparent. 



It was observed at Laurel, Md., that a large number, and 

 apparently a high percentage, of cicadas which had been com- 

 pelled to make their exit holes through a compact gravel walk, 

 were so injured in the process that they either did not win free 

 from the pupal shell, or having accomplished that failed to 

 complete their metamorphosis. The most common defect 

 was that the wings did not fully expand, being more or less 

 crumpled and withered in appearance; probably this was caused 

 by undue pressure on the wing pads occurring while the nymphs 

 were tunneling through the very hard sidewalk. 



The following observation on a dragon-fly feeding upon the 

 Periodical Cicada is offered as a contribution to knowledge of 

 the predatory enemies of the insect. On May 30, 1919, near 

 Laurel, Md., I flushed a Tachopteryx thoreyi from near the 



'Mat-late, C. L., Bui. 71, U. S. Bur. Ent. p. 85, 1907. 



