The sedge (Thricoptera) family of Ryhacophilidae is a world-wide spread insects group of high profile to fly anglers. The family is characterised by a green or greenish colour at the stage of larva, that makes it possible to imitate this large group with very few specific patterns. Based on the lateral gills appendages, some literature divides the genus Rhyacophila in 3 sub-genera: Hyporhyacophila, Rhyacophila (Pararhyacophila) and Hyperrhyacophila. In Europe there are 83 species so far classified.
The larvae of Rhycophilidae do not build a case like most of the caddis but live "naked" amid stones. They like running waters and live as well in strong currents, where they get a grip on the stones with a spiderweb-like secrete. They are carnivore and feed only on organic material and prey other larvae. In the picture on the left a Rhycophila has captured a Baetidie mayfly nymph. Picture on the right: the emerald green ventral view of a Rhycophila sp.
An important imitative stage for fly anglers is the hatching pupa, that is when the insect breaks out of the pupal cocoon and emerges, swimming, to the surface. In this stage the wings are already visible. Fishing with imitation of the pupa is done by casting the artificial upstream , letting it sink and then stripping it to the surface.
The winged insects are often taken by the fish in two cases, 1) while females lie the eggs by diving underwater or flying on surface and dipping the abdomen 2) as spent, that is when the sedges fall in the water and die, after the reproductive cycle. Good results on the surface can be achieved by fishing a pattern with the wings lightly spread from the axis of the body. The wings are realised with the central part of a hackle feathers, shaped by placing the feather in a form and burning the exceeding extremities with a lighter or candle. Lower picture: underwater view of the imitation floating on the surface. Upper picture: the same floating pattern, seen from above.
For many Rhyacophilidae the life cycle is determined by the temperature of the water, hatches of Rhyacophilidae can happen throughout the all year, with peaks beginning and end of summer. All in all there are several good reasons to have always a couple of them in our fly boxes.
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