32 IRON-BLUE DUNS AND SPINNERS 



Family . . EPHEMERID^ 

 Genus . . Baetis 



Species . .(P umilus 

 { niger 



PLATE IV 



The appearance of the iron-blue dun is sure 

 of a welcome from the fly-fisher. One of the 

 smallest of the duns, it seems nevertheless to 

 be a favourite with the trout, and one may 

 confidently look forward to a rise when this 

 fly is present in any quantity. I remember one 

 morning on the Kennet watching little droves of 

 olive duns sailing down the broad, smooth river, 

 with here and there an iron-blue interspersed 

 amongst them. A few trout were busily en- 

 gaged in picking out the iron-blue duns, 

 allowing the olives to sail away unnoticed and 

 untouched. 



The autumn iron-blues are smaller than those 

 appearing in the spring. It is suggested that 

 two broods hatch out during the season, the 

 spring flies being the larger. In the plate the 

 iron- blue and jenny spinner are drawn from 

 autumn and spring specimens respectively. 



The male spinner of the iron-blue dun is the 

 pretty little fly known as the jenny spinner, 

 which does not, however, often succeed in 

 tempting the trout to its fate. The female 

 spinner, on the other hand, is a favourite article 

 in the trout's diet, and is a minute insect with a 

 deep reddish-brown body. 



