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LIFE-HISTORY OF LESTES LED A SELYS. 



By R. J. Tillyard, B.A. 



(Plates xxxii -xxxiii.) 



This paper embodies the results of observations carried out 

 during the past two years. So far, the work done on the Odonala 

 of Australia has been limited to the description of species; not 

 a single life-history has yet been attempted. The group, as 

 far as Australia is concerned, has been singularly neglected. The 

 descriptions of known species we owe mostly to European ento- 

 mologists, who have never studied the insects on the spot, but have 

 received them from collectors here. Hence very little is known 

 of their habits and their life-histories. This paper then marks a 

 new departure in the study of Australian Odonata. 



The difficulties in the way of studying insects such as these, 

 whose early days are aquatic, are great. It has taken me two 

 years to complete the history of this common species. Many 

 points of dispute, notably as to the method of oviposition, can 

 oniy be cleared up by spending a great deal of time in careful 

 observation. Even so, there will generally remain points which 

 are still open to discussion. I have attempted here to put down 

 accurately all the observations I have made, and to draw the 

 correct conclusions from them. 



In breeding this species in captivity I used a large glass 

 aquarium, about 1 ft. 6 in. by 1 ft., and 1 ft. high. Besides this, 

 half-a-dozen glass jars were required for the observation of 

 isolated specimens. At my first attempt I tried a bottom of 

 clear sand, but the larvae did not do very well. After trying 

 various methods, I found that the best plan was simply to pro- 

 vide them with fresh water and plenty of water weed from their 

 native ponds. They appeared to thrive better on the tiny 

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