. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 6 THE PERIODICAL CICADA. It SO happened that one of the hxrgest 17-year broods, together with one of the largest 13-year broods, apj)eared simultaneously in the sum- mer of 1868. Such an event, so far as regards these two particular bloods, had not taken j)lace since the year 1647, nor will it take place again till the year 2089. There are absolutely no perceptible specific differences between the 17-year and the 13-year broods, other than in the time of maturing ; but while the insects forming these two classes
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 6 THE PERIODICAL CICADA. It SO happened that one of the hxrgest 17-year broods, together with one of the largest 13-year broods, apj)eared simultaneously in the sum- mer of 1868. Such an event, so far as regards these two particular bloods, had not taken j)lace since the year 1647, nor will it take place again till the year 2089. There are absolutely no perceptible specific differences between the 17-year and the 13-year broods, other than in the time of maturing ; but while the insects forming these two classes of broods are not specifically distinct, they are good and distinct races which do not cross, and I have therefore, for convenience sake, named the 13-year broods Cicada tredecim. TWO DISTINCT FORMS. It is not a little singular, also, that two distinct forms occur in both races—a large one and a small one—the former by far more numerous than the latter. This fact has been observed^in past years, and was. Fig. 1.— Cica da. A, cT of typical form ; c, d, genital hooks ; g, singing apparatus. B, tf of the small form (cassinii); e, /, genital hooks. (After Ki- ley and Hagen.) noticed in 1868 by independent observers in different parts of the country.* Indeed, it was observed by Dr. Hildreth, of Marietta, Ohio, as far back as 1830 {vide Silliman's Journal, XVIII, p. 47). The true Cicada septendecim of Linnieus (Fig. 1 A, ventral view of male), as as early as May 17, 1845, where lie controverted Dr. Smith's position to the effect that there were no 13-year broods; and that in the same paper, for May 5, 1858, he pub- lished another notice, headed "Cicada ; It was not till 1873 that I became aware of these facts though I had previously been in correspondence with Dr. Phares ; and though I have made every eifort since to obtain a copy of the original article to which Dr. Phares refers, both he and myself have utterly failed to do so. While, therefo
Size: 1693px × 1476px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectentomology, booksubjectinsects, booky
