Serratella ignita (BWO) fly fishing
The Serratella ignita is one of the classic mayflies for the summer months and its imitation can be well rewarding to any fly angler in Europe. It is widely spread throughout the continent and mass hatches are common. Furthermore, if there was a rank of preference of what insect fish like to feed on, I'd account the BWO dun at the second place of such hypothetical ranking list, right after the Ephemera danica. (Picture: subimago male, red spinner after turning into imago)