78 



and unique for a mosquito of our fauna I saw a phenomenon which strengthened 

 my supposition. After having sent the specimens to Prof. Simon Bengtson in Lund 

 and asked him to compare them with the specimens of 0. nigripes in the collection 

 of Zetterstedt, he kindly told me that a very similar specimen was caught in Scania 

 and was determined as 0. nigripes hut differed from this by a brighter colour and 

 in not being so hairy. In a small preliminary paper the specimens were then des- 

 cribed as 0. nigripes. Later on I learned that this determination was wrong. The 

 Royal Museum of Copenhagen possessed mosquito larva? from Greenland, from 

 where we have hitherto only got one single mosquito species: C. nigripes; they were 

 kindly given me by Inspector Lundbkck and will be described in the following; it 

 will then be seen that the two larva? differ very much from each other. 



It seems therefore that 0. communis in our country really can have two 

 generations and that the late autumn generation differs a little especially with 

 regard to colour from the spring generation. 



As described in the anatomical chapter the larva? have very short flabella?; 

 and are very well equipped with comb-hairs. Nevertheless they are not bottom- 

 feeders, but live mainly in the surface of the ponds, hanging down from it by 

 means of the flaps of the sipho. In this attitude the ecdysis takes place too, also 

 the last one from larva to pupa. The larva often hung down in such countless 

 numbers from sunlit surfaces of the forest ponds that they almost touched each 

 other. The millions of flabella?, all in activity about a centimeter under the surface, 

 must produce an uninterrupted water current, lifting a deeper water layer upwards 

 to the surface. The flabella 3 of 0. communis being very small, they act in quite a 

 different way to the large flabella? of Culiceta morsitans. Whilst the flabella? of the 

 last-named species strike about 100 to 180 strokes a minute by summer tempera- 

 tures, the flabella? of 0. communis strike with such an enormous rapidity that it is 

 quite impossible to count the number of strokes. Besides, the larva has also an- 

 other method of using the flabella?, and according to my view this is more signifi- 

 cant when the organ is to be used for gathering nutriment. We see that there are 

 always certain larva' which, when kept in aquaria, constantly hold the apex of 

 the sipho in the surface, suddenly bend the head upwards and now press also the 

 flabella? against it. Immediately after the bending of the corpus in a bow, the whole 

 body begins to describe a circle round the sipho which is held quite still; during 

 the circular movement the flabella? are pressed against the surface and used as 

 brushes which clean the underside of the surface of all adherent particles. 



Geographical distribution: The species has been so confused with <). 

 punctor (Kirby) that it is almost impossible to determine its range with certainty. 

 Most probably it is the most common forest mosquito with unhanded legs in North 

 and Central Europe. 



