Catalogue of the Odonata of Ohio. 



69 



94. Celithemis elisa Hagen. 



The first captures were by E. B. Williamson and R. C. Os- 

 burn at Sandusky, June 26th. This fine insect was common 

 around the marshes until the end of July. Taken by Mr. 

 Hine at Wauseon in August. 



Elisa in flight and habits very much resembles C. eponina. 

 It appears, however, to be the butt of odonate society for 

 Anax, Libellula, and C. eponina are sure to pay it their disre- 

 spects whenever they spy it in passing; they are sure to 

 make a dive for it and, as it appears, tear its gauzy wings; 

 for it was not uncommon to see the males, otherwise in good 

 condition, with the hind wings shredded. 



NOTES. 



1. The season of 1896 was somewhat at variance with that 

 usual in Ohio. The temperature remained constantly low 

 until April 10th, when summer conditions came suddenly 

 and continued almost without interruption until the usual 

 time of summer heat. In consequence several species 

 appeared weeks earlier than usual. At Columbus ten species 

 were taken in April and nearly forty in May. Five is the 

 highest number recorded for April in any previous year. 



2. A dearth of Odonates was looked for this year on 

 account of the prolonged drouths of 1894 and 1895. Such 

 was not the case ; on the contrary, both species and indi- 

 viduals were abundant everywhere that observations have 

 been made. It seems to follow that the nymphs somehow 

 are able to survive severe drought. Again, in more than one 

 instance, species of Diplax were seen industriously oviposit- 

 ing among the grass growing in the bed of a pond from 

 which the water had long since disappeared. Perhaps eggs 

 thus cast away may remain uninjured until the return of 

 water. 



3. It is well known that when the females of some species 

 are held with the wings back to back they soon begin rapidly 

 to extrude their eggs ; this seems to be an instinctive effort 

 to prevent their destruction, and doubtless often succeeds, for 

 the eggs are undoubtedly fertilized and when they happen to 

 fall into the water are saved. 



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