340 MONOGRAPH OF THE GENUS SYNTHEMIS, 



L i f e - H i s t o r y of S. enstalacta. 



The perfect insect emerges about the beginning of November, 

 and continues on the wing until March. Pairing takes place 

 from the middle of November onwards, but it is always difficult 

 to find either pairs in flight or females ovipositing. On a small 

 swamp at Leura, Blue Mountains, where the insect is common, I 

 have watched the female ovipositing in December. When pair- 

 ing, the male seizes the female in the usual way with his anal 

 appendages, clasping her round the prothorax, with the inferior 

 appendage bent forward over the front of the prothorax. In 

 this position they usually indulge in a wild up-and-down flight, 

 finally fl3'ing away into the bush. When a female appears on 

 the swamp there is usually more than one male ready to pair 

 with her, and often quite exciting scuffles occur before pairing is 

 effected. Pairs are also frequently heckled by single males^ 

 which sometimes succeed in separating them. 



When the female is ready to deposit her ova, she returns to 

 the swamp, flying low, and keeping as nuicli as possible out of 

 the main track of the numerous males flying up and down. 

 However, when she chooses to oviposit right in the track of their 

 flight, they seldom molest her. The place chosen for the eggs is 

 always the same, viz., in still water of from a few inches to a foot 

 or two in depth, overlying deep mud, and close to the main water- 

 drainage of the swamp. If one dredges such places in tlie early 

 spring, larvse of S. eustalacta will be found in abundance, but na 

 larvae of any otlier species. 



Although the female possesses a conspicuous ovipositor, it is 

 apparently of no use to her except perhaps in controlling the 

 exit of the egg-masses. She flies close to the water, along the 

 edges of the reed-beds, continually dipping the tip of her abdomen 

 into the water, so as to wash out the eggs, which fall down and 

 settle on the mud. This is done in characteristic fashion, with 

 the abdomen held nearly vertical and bruslied forward at each 

 dip, so as to touch the water gently. Sometimes the action 

 ai)pears to be done easily and not hurriedly, but at other times — 



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