58 INSECTS AND MAN 



the lover of nature there is something regrettable in this 

 slow extermination of an insect which represents, as does 

 the periodical cicada, so much that is interesting and 

 anomalous in its habits and life-history. During the long 

 periods of past time the species has recurred with absolute 

 regularity, except as influenced by notable changes in the 

 natural topographical conditions and the despoliation of 

 forests which has followed the path of white settlement. 

 It is interesting, therefore, taking as time measures its 

 periodic recurrences, until in retrospect it is possible to 

 fancy its shrill notes jarring on the ears of the early 

 colonists or listened to in the woodlands bordering the 

 ocean by the still earlier discoverers and explorers. Still 

 more remotely one can picture its song causing wonderment 

 to the savage Indians, who attributed to it baleful influences, 

 and yet, less dainty than their white followers, used the 

 soft, newly emerged cicadas as food; or further back in 

 time, when it had only wild animals as auditors. With 

 these long-time measures our brief periods of days, weeks, 

 months, and years seem trivial enough." 



The early study of this peculiar insect was one of great 

 difficulty, till it was discovered that two distinct races 

 existed : the one, limited to the northern half of the range 

 of the species, with a seventeen-year developmental period ; 

 the other, hailing from the southern half, with a develop- 

 mental period of thirteen years. The latter race has been 

 called Cicada tredecim, and, by many, it is considered 

 simply as the seventeen-year form with an accelerated 

 metamorphosis, owing to more favourable atmospheric con- 

 ditions. In colour, form, and habit, in fact in every respect, 

 except for the length of the developmental period, the two 

 resemble one another. In both races, however, there are 

 two distinct types : a large form, comprising the majority 

 of each brood, and a rarer, small, or dwarf form. The large 

 form (fig. 7) measures about one and a half inches from 

 the head to the tip of the closed wings, which have an 



