294 THE DRY-FLY MAN'S HANDBOOK 



The name black gnat applied by anglers for many- 

 generations to this insect is 

 Black gnat. a most inaccurate one. The 



fly is scarcely black, and cer- 

 tainly is not a gnat. It is one of the family Bibionida, 

 genus Bibio, and species johannis. The larvae are 

 cylindrical maggots living underground, feeding on 

 the roots of plants and destroying the vegetation. 

 They are whitish brown in colour, with brown head 

 and two biting mandibles. The pupa is dark brown, 

 of shrivelled appearance, and the wing cases are small. 

 The male black gnat {Bibio johannis) is shown in Plate 

 XXXVI. The female is broader and shorter in the 

 body than the male. In the new set of patterns the 

 imitations of them are Nos. 26 and 27, the male and 

 female respectively. 



This insect, one of the Chironomidse, must be 



described here. In the chapter 



Chironomus tentans. on " Dry- Fly on Lochs and 



Lakes " my friend Sheringham 

 has referred to its abundance in the Blagdon Lake, 

 and also to the fact that it is well taken by the trout 

 there. He submitted specimens to Mr. Mosely, who 

 identified them without much difficulty, and later con- 

 tributed an excellent article to the " Field " on the 

 subject. This, by the kind permission of the pro- 

 prietors and editor, I am allowed to reproduce 

 wholly or in part here. I will give copious extracts 

 from it. 



" A brief description of an insect, Chironomus 



