The Seventeen- Year Cicada on Staten Island between the 

 Years 1894 and 1911^ 



William T. Davis 



Next June our island will resound with the songs of the 

 seventeen-year cicada, Tihicen septendecim L., for 191 1 is 

 " Locust Year " in the valley of the Hudson. This brood covers 

 a considerable area and extends to the south into the mountains 

 of North Carolina. 



It is well known to entomologists that while the seventeen- 

 year cicada appears periodically in certain districts in great num- 

 bers, there are other years when it is to be found in the same 

 places but in less numbers. The limits of the various broods are 

 not sharply defined, and when a few seventeen-year cicadas are 

 found on Staten Island, for instance, there may be a considerable 

 visitation of them not many miles away. The advent of the 

 white man with his farming operations and the consequent de- 

 struction of the forests, have had an influence upon the cicadas 

 and, no doubt, broken up the broods to some slight extent. 



In the Proceedings of the Natural Science Association of 

 Staten Island for February 1894, an account is given of the 

 appearance of the seventeen-year cicada on the island between 

 the brood years of 1877 and 1894. In 1881 a considerable num- 

 ber appeared belonging to the brood now known as number VI. 

 In 1885, 1888, and 1889 only slight evidence was found of the 

 occurrence of the insect on the island. In 1890 and 1892 a few 

 were found, and in 1893 they were more numerous, but these 

 last may have been precursors of the general swarm of 1894. 



Since 1894 the seventeen-year cicada has been observed on the 

 island during eight different years, as appears by the following 

 chronological record. 



^Presented January 21, 1911. 



