This is a nice, all purpose pattern that could stand in for chrionomids-gnats-buzzers, as well as the larger Hawthorn fly. The simple body of wrapped pheasant feather fiber (or turkey, or very light dubbing) will have it floating low in the surface film. There is a foam wingcase-head here. The UK pattern is in response to the April/May ‘hatch’ of the terrestrial insects. But, the many on line variations of the Hawthorn (Bibio Marci) (see Google Images) suggests it would be a great pattern year round on streams and stillwaters. Additional bug info.
SwittersB & Exploring 