SB 

 818 



C578 NO. 45, Second Series. 



ENT 



aited States Department of Agriculture, 



DIVISION OF ENTOMOLOGY, 



L. O. Howard, Entomologist. 



A NEW NOMENCLATURE FOR THE BROODS OF THE PERIODICAL 



CICADA. 



By C. L. Marlatt, 

 First Assistant Entomologist. 



[Reprint from Bulletin No. 18, New Series, Division of Entomology, U. S. Department of Agri- 

 culture, pp. 52-58.] 



The writer reviewed the different nomenclatures suggested by 

 various authors for the broods of the periodical Cicada in Bulletin 

 No. 14, new series, of the Division of Entomology, and therefore 

 a brief summary of the old sj^stems is all that need be given here. 



It will be remembered that the earlier writers, viz, Prof. Nat. 

 Potter, Dr. William T. Harris, and Dr. G. B. Smith, classified the 

 broods solely according to the years of their aj^pearance. The 

 unpublished register left by Dr. Smith includes every brood now 

 known classified according to race, and gives the localities for one 

 additional brood, the existence of which seems not to have been con- 

 firmed. Though lacking any special designation for the broods. Dr. 

 Smith's classification is as complete and accurate as that published 

 by Dr. Riley and since followed by all later writers. Dr. Asa Fitch 

 was the first to introduce a numbering system for the different 

 broods, enumerating nine altogether, but his data wdre very limited 

 and he was not aware of the 13-year southern period, and there 

 necessarily resulted no little confusion of the broods of the two races. 

 The Walsh-Riley enumeration of 1878 gave the records for sixteen 

 broods, which were designated by Roman numerals from I to XVI, 

 the enumeration being based on the sequence of the different broods 

 after 1868. In 1869, in his First Missouri Report, Dr. Riley, having 

 in the meantime secured the manuscript paper of Dr. Smith, added 

 the six broods from this paper not represented in the Walsh-Riley 

 enumeration, increasing the number of the broods to XXII, and 

 renumbered them again in accordance with their sequence, beginning 

 with 1869. Several of these broods are rather unimportant, or lack 

 confirmation, and one of them, Brood III, was founded on an erro- 

 neous record and has been dropped. 



In the enumeration of the broods by Walsh-Rilej^ and later by 

 Rilej', the two races are mixed together and a sequence of numbers 

 given which, after the first thirteen years, lost all significance as a 

 record of the order of the broods in time of appearance, and from 

 the first obscured the true kinship of the broods in each race. If, on 

 the other hand, each race be considered separately and its broods be 



