22 FIRST ANNUAL REPORT OP 



brood (tredt aim) that I captured in May, though I took a few speci- 

 mens afterwards. 



THE SEASON OF THEIR APPEARANCE AND DISAPPEARANCE 



differs somewhat with the latitude, though not so materially as one 

 might suppose. According to the records, they appeared the past season 

 earlier in the South than in the North; but the last half of Slay can be 

 set down as the period during which they emerge from the ground, in 

 any part of the country, while they generally leave by the 4th of July. 

 In St. Louis county the past season they commenced issuing on the 22d of 

 May, and by the 2Sth of the same month, the woods resounded with 

 the rattling concourse of the perfect insect. As is the case with a 

 groat many other insects, the males make their appearance several 

 days before the females, and also disappear sooner. Hence in the 

 latter part of the Cicada season, though the woods are still full of fe- 

 males, the song of but very few males will be heard. 



That circumstances favorable or otherwise may accelerate or re- 

 tard their devolopment, was accidently proven, the past season, by 

 Dr. E. S. Hull, of Alton, Illinois; as by constructing underground 

 flues, for the purpose of forcing vegetables, he also caused the Cica- 

 das to issue as early as the 20th of March, and at consecutive periods 

 afterwards, till May, though strange to say these premature individ- 

 uals did not sing. They frequently appear in small numbers, and more 

 rarely in large numbers, the year before or the year after their proper 

 period. This is more especially the case with the 13-year brood. Thus 

 in Madison county in Illinois, and in Daviess and Clark counties in. 

 Missouri, there were in 1854 a few precursors to the true 1855 brood. 

 They were also observed in Madison county, Illinois, in 1867; while 

 M L. W." writing from Guntersville, Alabama, to the Country Gen- 

 tlemen of June 25. 1868, says, "some call them 11-year locusts." Other 

 such cases will be noticed hereafter. 



THEIR NATURAL HISTORY AND TRANSFORMATIONS 



have been sufficiently described in the standard works of both Harris 

 and Fitch, and it is only necessary to mention a few facts not recorded 

 by them. 



Mr. S. S. Rath von, of Lancaster, Pa., who has himself witnessed 

 four of their periodical visits, at intervals of 17 years, discovered the 

 following very ingenious provision which the pupae (Fig. 7, a) made the 

 past season, in localities that were low or flat, and in which the drain- 

 age was imperfect. He says: "We had a series of heavy rains here 

 about the time of their first appearance, and in such places and un- 

 der such circumstances, the pupas would continue their galleries 

 trom four to six inches above ground (Fig. 8, a full view, b sectional 



