rio\] 



[From THE ANNALS OF APPLIED BIOLOGY, Vol. Ill, Nos. 2 and 3, Jajidaby 1917.] 



[All rights reserved.] 



ON THE BIOLOGY AND ECONOMIC SIGNIFICANCE 

 OF TIPULA P ALU DOS A. 



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



{North of Scotland College of Agriculture.) 



Pabt II. Hatching, Growth and Habits op the Larva^. 



(With Plates XVIII— XX and 3 Text-figures.) 



The most common species of Crane-fly larva occurring in grass 

 and com land in the north-east of Scotland is Tipula paludosa. Tipula 

 oleracea occurs also, but is much less frequently met with. Along 

 with these, there has also been found in comparatively small numbers 

 in fields the larval stage of Pachyrhinu histrio, but this species appears 

 to occur more frequently in garden ground. The following Tipulidae 

 in addition have been found in the winged stage in the district sur- 

 rounding Aberdeen: 



Tipula varipennis, common and generally distributed. 

 T. gigantea, in small numbers. 

 T. lutescens, in small numbers. 



Pedicia rivosa, L. widely distributed in the northern area, but not 

 common. 



The Egg. 



Hatching of the flies goes on during the months of June, July, 

 August and September, and as already recorded (Part I) the first 

 mating and oviposition may take place within a very short period. 

 In captivity, hatching mating and oviposition have all occurred within 

 a few hours. A newly hatched female contains considerably over 400 

 shelled ova. In two such taken at random the actual numbers were 

 found to be 448 and 490. A third female captured out of doors in coitu 

 contained 255 black shelled ova together with a quite small number — 

 about 12 — of pale coloured immature shelled examples. The form of 



1 The work recorded in this series of papers has been carried out with the aid of 

 Grants from the Board of Agriculture for Scotland. 



