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ON THE BIOLOGY AND ECONOMIC SIGNIFICANCE 

 OF TIPULA PALUDOSA. 



By JOHN RENNIE, D.Sc, F.R.S.E. 



(North of Scotland College of Agriculture.) 



Part I. Mating and Oviposition. 

 (With Plate XXXVI.) 



In the course of the summers of 1913 and 1914 the mating and 

 oviposition of Tipula paludosa formed the subject of special study 

 both in the field and in laboratory experiments. As far as the writer 

 knows no account of the sexual behaviour of this species is on record, 

 at all events in detail. The points of special interest which have been 

 made out are summarised in the present paper ; the observations of 

 the first season have been confirmed in the second. 



Mating. 



The earliest occasion in a season upon which mating was observed 

 in progress was 20th June, 1914. This was in a field cage in which 

 the flies had hatched out naturally. In the previous year, when a closer 

 watch was kept, and the flies were reared in captivity and probably 

 hatched earlier than in the field, the date was actually later, viz. 

 4th July. It may here be mentioned that, as detailed in a subsequent 

 paper, there is only one generation of this species in the year in the 

 north of Scotland. In the south of Britain it is held that two 

 generations occur. 



The flies experimented with were reared from larvae which had 

 been kept in field and laboratory cages. The pupae were collected 

 and transferred to small vessels about the size of ordinary flower pots 



The work recorded in this and subsequent papers has been carried out with the aid 

 of grants from the Board of Agriculture for Scotland. 



