SEVENTEEV-YEAR LOCUST: ITS LIFE-HISTORY. 



173 



Time of Appearance. 



The time of the appearance of the insect would, of course, vary with 

 the latitude, the southern ones being several weeks earlier than the ex- 

 treme northern. In general terms, it may be stated as in the latter part 

 of May. Dr. Harris states that "in Alabama, they leave the ground in 

 February and March; in Maryland and Pennsylvania in May, but in 

 Massachusetts they do not come forth until the middle of June." 



In the extensive brood of 1868, which reached from the Atlantic to 

 west of the Mississippi river, individuals were first noticed in Maryland 

 and Pennsylvania from the 20th to the 25th of May; in Illinois on the 

 19th of May, and at St. Louis, Missouri, on the 2 2d of the same month. 

 They usually continue for from five to six weeks, although straggling 

 specimens may sometimes be seen for weeks later. 



Life-History. 



For detailed description of the egg, larva, pupa and perfect insect 

 the First Report of Dr. twitch may be consulted, and for the natural his- 

 tory, the excellent volume of Dr. Harris. It may suffice for this pres- 

 ent notice, to state that the female selects a small branch 

 of an apple-tree, oak or some other hard wood, near its 

 tip, into which to place her eggs, always taking a position 

 with her head directed toward the trunk. With her ovi- 

 positor shown at h, in Fig. 44, she saws little slits in the 

 twig, making an oblique hole to the pith, and en- 

 larging it into a fissure with splintered outward 

 edges, as represented in Fig. 45. In each of 

 these she places from ten to twenty eggs, in pairs 

 side by side, but separated from each other by 

 portions of woody fibre, and inserted somewhat 

 obliquely so that their ends point upward. About 

 fifteen minutes are required to make a fissure and 

 fill it with eggs. Moving backward toward the tip of the branch 

 another and others are made in line — sometimes to the num- 

 ber of fifty, if the twig be favorable for the purpose, by the 

 same insect. Her complement of eggs is from four to five 

 hundred. The female, exhausted by her labor, soon there- 

 after drops from the tree and dies. 



The time required for the hatching of the eggs has been 



variously stated at fifty-two days, forty-two days, and even so 



low as fourteen days. t«ms"pi")c'- 



The newly-hatched Cicadas — about the one-sixteenth of an cica'ia.* "'* 



inch long, and shown in Fig. 46 — are slender, grub-like creatures, lively 



Fir.. 41. — CiCAD.v 

 SEPTEXDKciM. show- 

 ing al«, til" beak; at 

 b, till! ovipositur. 



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