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NOTES ON CICADAS. 

 By Walter W. Froggatt. 



Regularly every season as the warm summer days set in, toward 

 the latter part of the year, the shrill call of the Cicadas, or "locusts " 

 as they are popularly called, is heard with monotonous regularity 

 in every cluster of trees or shrubs about Sydney. It is noticeable 

 that every third year they appear in much greater numbers than 

 in the two preceding seasons; and with the well known fact 

 before us that the American " Seventeen-year Cicada " (C. 

 septemdecim) reappears every seventeenth year, I am led to the 

 conclusion that several of our larger species take three years to 

 reach maturity. 



During this last season (1894-5) they appeared in countless 

 numbers all round the neighbourhood of Sydney, and were much 

 more in evidence about the suburbs than they had been for many 

 years previously. The paddocks about Croydon were literally 

 covered with the tubular holes through which the pupte had 

 escaped, while every tree trunk and fence was festooned with the 

 dry larval skins split down the middle of the back and firmly 

 fixed in position by the powerful claws of the fore legs. For fully 

 three months they kept up one continuous screech, unless a 

 thunder storm sprang up, and then every Cicada was mute. 

 Acting on a suggestion made by Dr. Cox at one of our meetings 

 some time ago [Proceedings iii. (2), p. 1508], I jotted down a 

 number of observations made in the bush under these very favour- 

 able circumstances, of which the following notes are the result. 



At Croydon the first Cicada was heard on the 30th of October 

 about sunset, and a few days later I caught several of the small 

 black ones (Melampsalta melanopygia, Ger.). In February their 

 dead bodies began to be plentiful under the trees, and the calls of 

 the survivors were fitful and irregular, according to the state of 

 the weather, being heard only on fine days. The last heard at 



