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ZOOLOGICAL SOCIETY BULLETIN. 



SEVENTEEN-YEAR "LOCUST." 



Cicada septendeckn- 



This insect is not a true locust. The locusts 

 belong to the order of grasshoppers and their al- 

 lies, which are voracious feeders. Actual swarms 

 of locusts are very destructive to vegetation, but 

 these do not occur in the eastern United States. 

 The damage from a swarm of the seventeen-year 

 "locust" is superficial. 



The present species lives in the ground for seven- 

 teen years. In the winged state it lives about 

 five weeks. The eggs are embedded in branches 

 of trees. From the point of injury the branch 

 usually dies. This is the only damage done. The 

 insect in a winged state does not feed. 



MOUNTED SPECIMENS. 

 Prepared for the schools. 



been affected by grading and drainage. Such 

 changes in the character of the soil appear to 

 be fatal to the larvae. A marked illustration 

 was a narrow strip of woodland along the East 

 Chester Road. Here the ground was honey- 

 combed with burrows and it was impossible to 

 take a step without trampling the larval shells 

 under foot. North of this was a partially im- 

 proved or drained area, extending considerably 

 over a mile and without traces of the insects. 



Up to the 4th of June, there were no indica- 

 tions of tlie Cicadas depositing eggs. They ap- 

 pear to be extremely sensitive to low tempera- 

 ture and a cold evening so benumbs them that 

 myriads fall to the ground and lie helplessly on 

 their backs. They will not endure close con- 



DESCR1PTIVE LABEL. 

 Back of tablet opposite. 



finement and several batches of over five hun- 

 dred each lived less than forty-eight hours. 



The days of the 5th, 6th" and 7th of June, 

 were marked by a steady northeast wind, with 

 intermittant rain and a low temperature. Ob- 

 servations on June 8, a day of bright sunshine 

 and rising temperature showed that the swarms 

 had not been permanently affected. 



The entire day of June 10 was spent in in- 

 vestigating the swarms along the Palisades of 

 the Hudson. The insects were particularly 

 abundant in the vicinity of Fort Lee and Coytes- 

 ville, New Jersey. Near these towns they ex- 

 isted in enormous numbers and the continuous 

 hum from the trees was actually trying to the 

 nerves of the observers. On this day the first 



TWIGS IN WHICH THE FEMALE CICADA HAS DEPOSITED EGGS. 

 The powerful ovipositor penetrates the twig to a depth of at least a quarter of an inch, raising the small spurs of wood 

 along the sides of the twig as shown in the photograph. Sometimes the punctures are so deep that the twig is twisted off 

 by the slightest breeze. 



