SB 818 C57 ENT 8 NO. 45, SECOND SERIES. 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 systems 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 appearance. The unpublished register left by Dr.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 were 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-Riley, and later by Riley, 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 arranged in a series in accordance with their sequence in time, an important natural relationship in point of origin and distribution is plainly indicated. Taking first the broods of the 17-year race, it will be seen from the subjoined table that if the enumeration begin with Brood XI, the 17-year broods follow each other in regular succession for eleven consecutive years; then after a break of one year follows Broods V and VIII, and after another break of one year, Brood IX; another break of one year precedes the next recurrence of Brood XI, with which the series starts. . Chronological order of the broods of the Cicada from 1893 to 1910. 6] / f : | 17-year |; 13-year | rae rere 17-year | 13-year Year race. | race. Year. race. | race. | PSOne ccc cccwawcactstm te cees XI XVI TQO2S seer ee eet See te ed. 2 1) ae eee ee 79), See XTT,,| RSV || 19032 ee sh ES Ly | BOkan a Ola SOME ces oceans we eee ke eee SLE II 1904_ oe 5 = Lae - if cs TE XIv | TFN || 0905 a enna, eR Se Vile ee A OUHME <2 oa Me wi ca dubonee oe XV} VAD i 90 Ge 6 ere SN VIII XVI che 1): ee a Me pee ar = XVII | BVA EWA ie BY 0 fen Se Le ee Ba ee XV [ee PDR cea || 51008, jue eine taco ibe u MOQQE . 2.20 2285.42 eee DO. | Bote Seeeee TGQG Rane eer mee oa eee | ees ee IV 90M ae. Seen ees eee | XXI | xX OTOL Seer aera LSS ee XI VI Taking up the 13-year broods in the same way, it will be seen that if the enumeration start with Brood X VI, a 13-year brood follows in regular succession for six years. With the exception of the very doubtful Brood X, which is separated from the last 13-year brood by three years, there follow seven successive years in which no 13-year broods occur. Under the supposition that the different broods of the 17-year and 13-year races sprang in the remote past from an original brood of each, it would naturally follow that the broods most closely related in time would also present a closer relationship in their range, and this, in fact, proves to be generally true. To show this relationship and to indicate the natural order of their occurrence, I have to suggest a new enumeration of the broods in which the two races are separated—the 17-year broods coming first, followed, for convenience merely, by the 13-year broods. Thus Brood XI of the 17-year race becomes Brood I, and the others are numbered in the regular order of their occurrence, except that I have assigned a brood number to each of the seventeen years. This leaves Broods XII, XV, and XVII, as newly numbered, without any definite colonies, so far accepted, as representatives of estab- lished broods. As will be shown later, however, there are records which indicate the existence of small or scattering broods filling the three gaps mentioned in the 17-year series. In the renumbering the broods of the 13-year race I have contin- ued for convenience from the end of the series of the 17-year race, the first 13-year brood becoming Brood XVITI, and I have assigned brood numbers to each year of the 13-year period, making a total enumeration of the broods of both races of XXX. As already indicated, six of the numbers given to the 13-year race have had no brood assigned to them, although records have been secured which seem to indicate the existence of scattering broods filling some of the gaps, as will be noted in the records given further on. It does not necessarily follow, in fact it is quite unlikely, that Brood I, as here designated, is the original or oldest brood of the 17-year race. Undoubtedly some of the 17-year broods, perhaps half or more of them, originated by retardation of individuals, and perhaps half by acceleration of individuals; so that the original brood, if it still exists, is more likely to be one of the intermediate ones. Brood X, being the largest of the 17-year broods, perhaps has best claim to this distinction. For the same reasons an intermediate brood in the 15-year series is doubtless the original brood of the 13-year race, and this title may possibly belong to Brood XIX which has the widest range of all the broods of the 13-year race. The fewer number of broods in this race would seem to indicate that it is of later origin than the 17-year race, and this belief is further justified by the fact of its occupying, in the main, a territory of later geographical formation. The following table, beginning with 1893, when the initial broods of both the 17-year and the 13-year series appeared in conjunction, illustrates the new nomenclature suggested, and in parallel col- umns also are given the corresponding nomenclatures proposed by Professor Riley, by Walsh and Riley, by Fitch, and the year records in Dr. Smith’s register :* Nomenclatare of the broods of the periodical Cicada. Broods of the 17-year race. Broods of the 13-year race. | Jere dS Et : EES —_____—_ ailsh Year. proposed Riley Walse Fitch | Smith Proposed) Riley Waieh; Fitch | gmith enumer- | num- | crea | num- regis- |enumer-| num- | eel ; num- register. ation. | bers. | pers | bers. | ter. ation. | bers. | pers | bers. Meets a5 | I 0.41 194 Nace eee | a See 1842 | XVIII REV ie see ee sistent 1854 Lee ed ||) VLE 1 1843 XIX |'XVIII | XIII 3 | 1842-1855 III | XIII TX ||sea2s2 | 1844 xx Th ereeuae peck gece 1843 IV | XIV Xeg (beeen eee 1845 XXI | Via Santee |beses eel 1844 Ws XV | 2-4 I ose 1846 XXII | VI | TV, | eee 1845 VI} XVII XII | 7 1847 | XXIII} VII | Vv 5 | 1846-1559 VIL SRATERG |S Seek See 1848 DO. CINE I leet onan fame eee ss (scce cons Geers ccs Vill xx XIV 2-8 1849 D2: ©) fq ane ee ea | eee Ane TX XXI XV 5 1850 | XxXVI 2 SF Pees ee. | 1849 2:69) | )..4 (ES D-aial 1 1851 2: @. Of OE ee eer (Seer er |= ec an xa) 1 i 9) 1852) | EXEXOVIIET, We 222 a= [he ee | ee ee eee SSOUMGIE =oecs0 | TE esses 8 le BBB N Is RERUNS || Comme OO VE ee eee (eee ee XII Vell 0G 6 | 1854 5.3.6. c) Pee mee [aia Ema Ae AS SS XIV VILL | VI 3} 1855 VTL eenoVil 2 abe Se | eee 1854 | | XIX (XVIII | XIII 3 | 1842-1855 |. .9.G 111 ih eS ewe Se 1843 =| es XXI IV eae ere | 1844 | *In Bul. 14, Div. Ent., U. S. Dept. of Agr., the Riley numbers given in col- umn 2 were employed, and should be corrected to the later enumeration indi- cated in column 1. THE RELATIONSHIP OF THE DIFFERENT BROODS. As arule the relationship of the broods in point of distribution agrees with their kinship as indicated by their sequence in time of appearance. The relationship indicated by the latter, viz, their sequence in time, is doubtless untrustworthy as indicating origin, in some instances, on account of the uncertainty arising from the action of the principle of retardation on the one hand and acceleration on the other in the forming of new broods. In the case of a widely scattered brood, like Brood VI, it is quite possible that certain swarms originated from a later-appearing brood by retardation of individuals, and other swarms from an earlier brood by acceleration in time of appearance of individuals. This same condition may be true of other of the more scattered broods, but with the broods presenting a compact range a singleness of origin is evident. Examination of the distribution of the broods in connection with their sequence in time of appearance indicates, however, a certain relationship between the different broods in point of origin, which may be indicated as follows: THE RELATIONSHIP OF THE 17-YEAR BROODS. From the standpoint of distribution the broods of the 17-year race may be grouped as follows: (1) Broods I and II; (2) Broods III and IV; (3) Brood V; (4) Brood VI; (5) Broods VII, VIII, [X, X, and XI; (6) Broods XII, XIII, XIV, and XV; (7) Broods XVI and XVII, the last connecting again with Brood I. Taking up these broods in regular order: The main body of Brood I occupies territory immediately west of the more important Brood II, and also presents a number of colonies extending westward to Colorado. Broods I and II seem, therefore, closely allied in point of origin. Brood III presents little, if any, relationship to Brood II in point of location and distribution, but is closely allied to the following brood, IV, and the latter is evidently a western and southern exten- sion of III. Brood V presents little relationship with Brood IV in point of dis- tribution and covers a very compact territory. Brood VI, being a widely scattered one, and occurring usually in small numbers, does not seem to present any particular relationship with any of the preceding or following broods. Brood VII is local in distribution and not very important, and is divided into two sections by the territory occupied by the following Brood VIII, with which it thus seems to be closely allied. Brood LX is very distinctly a southern extension of Broods VII and VIII. 5 These three broods seem, therefore, to be closely allied in their origin, and, curiously enough, occupy territory which divides the two main sections of the great 17-year Brood X, which next follows in regular succession. Brood XI, following X, is evidently an extreme northeastern extension of the latter. Brood XII, immediately preceding XIII, is represented by a series of colonies connecting the western Brood XIII with group 5. Brood XIII is the principal representative of group 6 and represents a large western group of the 17-year race of group 6, which comprises the main western branch of the 17-year race, as group 5 clustered about X is the principal representative of the eastern branch of the same race. Brood XIV has a very wide range to the eastward of XIII, and connects with the latter through the colonies in northern [linois and Indiana. Brood XV, following XIV, is limited to the Atlantic seaboard with the exception of one doubtful colony in Indian Terri- tory, and connects directly with the eastern colonies of XIV. Brood X VI is based on somewhat doubtful records, the Colorado locality perhaps being due to confusion with some other species, and the other records needing confirmation. Brood X VIT is intermediate between Brood XVI and Brood I, its western colonies connected with the former and the eastern colonies with the latter. THE RELATIONSHIP OF THE 13-YEAR BROODS. The broods of the 13-year race break up into the following natural groups: (1) Related closely to Brood XIX, and comprising Broods XVIII, XIX, and XX; and (2) related to Brood XXIII, and com- prising Broods XXI, X XII, XXIII, and our new Brood XXIV. The first of these broods, Brood X VIII, is a rather insignificant one and is undoubtedly an eastern extension or offshoot of the great 13-year Brood XIX, which succeeds it. Brood XX is undoubtedly a section of -Brood XIX retarded one year, just as Brood XVI is an accelerated swarm of the same. Both represent eastern extensions of the parent brood. Brood XXI, separated from Brood XIX by two years, seems to bear little relationship to the latter, and a more logical arrangement consists in connecting it with Brood XXIII through Brood XXII, of which last it may be considered as an eastern and northern exten- sion. Brood X XII is a very marked instance of the formation of a new brood by an acceleration in time of the appearance of a portion of a larger and older brood. Its relationship with Brood X XIII is very marked and can not be questioned. Brood XXIII, the main representative of this group, is followed by the new Brood XXIV, which is evidently a retarded swarm of the preceding brood. Of the new Broods X XIX and XXX, both of which need verifi- cation, no significant relationship can be pointed out. 6 Brood X XIX is very doubtful, and the records are possibly based on confusion with the 17-year race. NEW BROODS 17-YEAR RACE. Brood XII, 1904.—If his records are correct, this brood is the one referred to by Dr. G. B. Smith as occurrring in 1853 in Vinton County, Ohio, and Jo Daviess County, Il. Its recurrence seems not to have been recorded either in 1870 or 1887, and Smith’s records are therefore open to question. Mr. J. R. Burke, Milton, Cabell County, W. Va., writing under date of May 22, 1897, says: ‘‘ The Cicada is not due here until 1904; its last visit was in 1887.” Mr. W.S. Herrick, Thurman, Allen County, Ind., writes under date of June 10, 1898, that ‘‘ We had the 17-year locust in 1887, if I remember correctly.” This is also a doubtful record, and it is possible that he referred either to Brood XXII, occurring in 1885, or Brood V, occurring in 1888. That all these records are open to some doubt is apparent, but they are of sufficient importance to warrant investigation in 1904. Brood XV, 1907.—This brood is represented by the colony appear- ing at Tivoli, Duchess County, and Galway, Saratoga County, N. Y., in June, 1890, as recorded by Prof. J. A. Lintner in his Seventh Report, pages 297-301. Mr. Davis records the occurrence of scat- tering individuals the same year on Staten Island. In a letter of June 2, 1890, Prof. J. B. Smith, New Brunswick, N. J., reports that the periodical Cicada had been taken by several Newark collectors, and had also been observed at Anglesea, Cape May County. Another record which perhaps applies to this brood is given by Mr. I. N. Smith, Scotland Neck, Halifax County, N. C., in letter of June 22, 1885. He reports that his ‘‘ First recollection of the locust was about the year 1839 or 1840, when the whole of the white-oak lands were filled with them. * * * In 1855 or 1856 they appeared again, but nothing to compare with the period first stated. The locusts were all on the white-oak land and on the Roanoke River and not on the pine lands.” Assuming the dates 1839 and 1856 to be the correct ones, this would throw this swarm of Cicadas into Brood XV, and if there are any representativs left they should reappear in 1907. The late Mr. W.8. Robertson, of Muscogee, Ind. T., in a letter of June 17, 1879, incidentally mentioned also the occurrence of a brood of Cicadas 1839. This record could not fall in any one of the old broods, and if it belongs to the 17-year race it would be an extreme western outpost of XV. Brood X VII, 1909.—A very definite record which may coincide with this brood is furnished by Mr. Theodore Pergande, of this Division, who states that Mr. Rosseau, of Charlottesville, Albemarle i County, Va., informed him that the Cicada was very numerous in that place in 1875. His informant was positive as to the year from its being the one in which he made a trip to Europe. Another record is given by Mr. John D. Macpherson, Manassas, Prince William County, Va., in letter of July 3, 1895. He writes: ‘*T came here on the 23d of June, leaving the Cicada in full song in Washington (Brood X). Finding none here, I made inquiry and was informed that they appeared in full force in this county (Prince William) in the year 1875. This information I regard as reliable, the date being fixed as the year following the marriage and arrival of my informant in this county.” These Virginia swarms are evi- dently precursors of Brood I, with which they are therefore closely allied. A western extension of this brood seems to be indicated in the record furnished by H. J. Giddings, Sabula, Jackson County, Iowa. He writes, ‘‘ during last June (1892) the periodical Cicada was quite common here. * * * JT thought it was unusual to find them in such numbers four years after their regular appearance. The last regular year was 1883.” (See Insect Life, Vol. V, page 200.) If belonging to the 17-year race, the two records following should also be assigned to this brood. Mr. A. J. Julian, Woolleys Ford, Hall County, Ga., reports under date of June 14, 1898, that the Cicada was present there in 1892. Mr. J. W. Seaton, Strasburg, Cass County, Mo., writes under date of June 9, that the Cicada last appeared in that county in the summer of 1892 and in the summer of 1896, being numerous both years. The 1896 record refers to the 17-year Brood IV, and hence the record of 1892 is probably also of the 17-year race occurring in the same district. The scattering specimens recorded by Mr. Davis as occurring on Staten Island in 1892 may also be assigned to this brood. NEW BROODS, 13-YEAR RACE. Brood X XIV, 1899.—Mr. P. Lynch, Commerce, Scott County, Mo., under date of December 24, 1874, reports that the Cicada ap- peared in the summer of 1873 in considerable numbers, coming in June and remaining about two months. ‘‘ Their eastern limit in this county (Scott) was the Mississippi River, but they were as nu- merous on the opposite side of the river in Alexander County, Ill.” Mr. W.S. Campere, Pickens Station, Holmes County, Miss., writes under date of February 27, 1875, that the Cicadas appeared in great numbers in April, 1873. These two records would indicate a brood originating doubtless by retardation of individuals of Brood X XIII. Brood X XIX, 1894.—It is possible that the following records apply to a 13-year race, and in that case should be assigned to our Brood No. X XIX. WALA ; 3 9088 01272 Mr. C. J. Wellborn, Blairsville, Union County, Ga., writes under date of June 12, 1885, that ‘‘in May, 1878, locusts appeared south of this place and the northern limit then was the present southern limit of the territory covered now (by Brood X, 1885).” Mr. James Pagon, Winnsboro, Fairfield County, 8. C., writes that locusts appeared in South Carolina in 1878, but does not give definite localities. Both these records need confirmation. Brood X X_X, 1905.—Mr. B. H. Brodnax, Brodnax, Morehouse Parish, La., writes under date of May 13, 1892, that Cicadas are scatteringly present, and in a later letter he asserts that the insect in question is the periodical Cicada, with which he is familiar. The records given above Of new broods of the 15-year race are rather unsatisfactory, and it may be true that the 15-year race has not by any means distributed itself over its entire period, and the broods still cluster about the two main representatives of the race, namely Broods XIX and XXIII. WASHINGTON, D. C., May 1, 1902. o a wv