54 



quitoes; its life-history has there been worked out by BRESSLAU in an excellent 

 study (1917 p. 507). It is hatched in the large meadows which are flooded with 

 water twice a year, in spring and summer, owing to the hayharvest. It was ascer- 

 tained that no mosquitoes were flying before the first inundation took place; only 

 two days after this the w r ater teemed with larvae which, at a tp. of 20 25 C., in 

 the course of from 14 to 18 days, gave enormous swarms of mosquitoes. In June 

 and July no other brood appeared in the small waterpools which remained in the 

 now dry meadows. The mosquitoes were to be found at first in the meadows, later 



Textfig. 3. Pond near Tjustrup. O. vexans, communis, cantons, stamm phot. 



on in cottages and stables. In June the mosquitoes appeared again over the mea- 

 dows, and the egg-laying process took place; the eggs were laid upon w r holly dry 

 ground. Experiments showed that the eggs were laid singly or in small batches, 

 and that they had no apparatuses which could be used for floating purposes. 

 After the second inundation the water teemed with larvaB again and, owing to the 

 higher temperature, in the course of a week this generation was hatched. In the 

 middle of July this second generation visited the meadows and laid their eggs. The 

 species most probably hibernates as eggs, but it is possible that they also hibernate 

 as larvae. SCHNEIDER (1914 p. 33) maintains that he has found females in December. 

 GALLI VALERIC on the seventh of March. I refer also to the interesting supplementary 

 remarks by ECKSTEIN (1919 p. 97). The larva has been described by SCHNEIDER 

 (1914 p. 32) and ECKSTEIN (1919 p. 294). The larva must resemble that of 0. can- 



