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THE PERIODTCAL CICADA 
SUMMARY OF THE HABITS AND CHARACTERISTICS OF THE 
CICADA. 
T]\o jxM-iodical Cicada, often orroneously called the " 17-yeai' 
locust," or merely tlie "locust" — a term which should apply only 
to i2:rassho})})ers " — is, in the curious features of its life history, 
und()ul)tedly the most anomalous and interesting of all the insects 
peculiar to the American Continent. This Cicada is especially 
remarka])le in its adolescent period, the features of particular diver- 
gence from other insects being its long subterranean life of 13 or 17 
years, during all of which time its existence is unsuspected and 
unindicated by any superficial sign, and the perfect regularity with 
which at the end of these periods every generation, though numbering 
millions of individuals, attains maturity at almost the same moment. 
To the naturalist, familiar in a general way with the peculiar habits 
of this Cicada, its regular periodic recurrence always arouses the 
keenest interest on account of the anomalous life problems presented. 
To those unfamiliar wdth its habits, these sudden recurrences not 
only startle but often excite the gravest fears for the safety of trees 
and shrubs or even of annual plants. 
In view of the damage often occasioned by unusual insect out- 
breaks, such fears are not unreasonable, when, without w^arning, this 
Cicada suddenly emerges over greater or smaller areas, filling the 
ground from which it issues with innumerable exit holes, swarming 
over trees and shrubs, and making the air vibrate with its shrill, 
discordant notes. During its short aerial life it leaves very decided 
marks of its presence in the egg slits which thickly fill all the smaller 
twigs and branches, the killing or injury of which causes some tem- 
porary harm and a sort of general twig pruning not especially inju- 
rious to forest trees, but more so to fruit trees, and very undesirable 
and disastrous to young trees and nursery stock. (See PI. I.) 
o The confusion of the Cicada with the true locust or grasshopper was a natural one 
and appeared in the earliest published notice of the Cicada (1GG6), and the name locust 
has ever since remained the popular designation of this insect. The sudden appear- 
ance of the Cicada in vast numbers very naturally recalled to the first observers the 
hordes of migratory locusts or grasshoppers of the Old World, as Say and Fitch early 
pointed out. 
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