DIPTERA. 361 



Bibio marci, L. (St Mark's Fly). 



This insect is known as a dung-fly, and has never been considered 

 as a forest insect. Its connection with forestry was introduced to me 

 through Mr Thring, Boughton Kettering, who sent me samples of one- 

 year seedling ash very much eaten on the thick portions of the root. 

 The damage varied in appearance, and was therefore suggestive of 

 being the work of different insects. Mr Thring kindly sent me some 

 larvae on ash seedlings. They changed into pupse near the end of March, 

 and hatched* out flies (fig. 339) about the beginning of May, which 

 were identified by Eev. W. J. Wingate, Bishop Auckland, as Bibio 

 ward. Judeich and Nitsche say they are not of much importance in 



s 



^Ur- -*$&*~ ^k L 



Fig. 339. Bibio marci. 

 a, females ; b, males. 



forestry ; but the roots in question were very much injured, and Mr 

 Theobald informs me that they are often very injurious to the roots 

 of hop and other plants. 



References to Literature consulted. 



Binnie, Francis G. On the Asphondyliro of the Glasgow District. Nat. Hist. 

 Soc. Glasgow. 1876. 



Cambridge Natural History. Insects. Part II. 1899. 



Collinge, Walter E. Report on the Injurious Insects of the Midland Counties. 

 1904-6. 



Collinge, Walter E. The Life-history of the Pear Midge. 1905. 



Frank. Die Krankheiten der Pflanzen. 1896. 



Gardener's Chronicle, various articles from. 1870. 



