16 ENTOMOLOGICAL SOCIETY 



A SUCCESSFUL SEVENTEEN-YEAR BREEDING RECORD 

 FOR THE PERIODICAL CICADA. 



By C. L. Marlatt. 



The long underground life of this most wonderful of Amer- 

 ican insects always arouses, in the minds of those who have 

 not given the subject study, doubt as to the accuracy of the 

 records. This doubt can exist in the mind of no one who has 

 followed the history of this insect as recorded by Hildreth, 

 Potter, and Smith, and many modern observers, but the proof 

 for, respectively, the 17 and 13-year periods for the develop- 

 ment of the cicada has hitherto been based, for the full term, 

 solely on chronological records of occurrences. To silence the 

 skepticism which arose from the lack of actual breeding rec- 

 ords the late Professor Riley was for many years interested 

 in demonstrating, by rearing experiments, the validity of the 

 long underground development of this insect ; in other words, 

 to follow a particular generation throughout its subterranean 

 life of 17 or 13 years, as the case might be, watching its devel- 

 opment and preserving examples of the different stages. 

 Many experiments were made, some of them being efforts to 

 rear the insects about potted plants, and others to follow par- 

 ticular broods in the field. The difficulty of keeping potted 

 plants in a healthy condition for so long a period, especially 

 where examinations of the soil must needs be made from time 

 to time, together with the unreliability of caretakers, led to an 

 early failure of all such efforts. The first attempts to follow 

 the development of the cicada in the field in Missouri were 

 successful in a measure, but here again the experiment failed 

 because of the difficulty of keeping up observations in a par- 

 ticular place over so long a period. Observations, however, 

 were made on a brood in Missouri under Doctor Riley's direc- 

 tion by Mr. J. G. Barlow for a period of ten years. These 

 observations related to the 13-year brood appearing in 1881, 

 and during these ten years the larvae of the cicada had slowly 

 increased in size through the four larval stages, and were ready 

 to enter the first pupal stage. 



A much more careful series of experiments was instituted in 

 connection with the 17-year brood making its appearance in 

 1885, and the 13-year brood of the same year. Quantities of 

 eggs of the 17-year brood were collected in Virginia and dis- 

 tributed under certain linden and oak trees on the grounds of 

 the Department of Agriculture at Washington, D. C. A very 

 considerable quantity, also, of eggs of the same brood were 



