dcabarle
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Isonychia bicolor is a species of mayfly commonly referred to as the "mahogany dun" or "slate drake" by anglers. Here are some details and facts about this mayfly species:
- Habitat: They are found in many streams and rivers, especially in the Eastern United States. These mayflies prefer clean, running water.
- Life Cycle: Like other mayflies, Isonychia bicolor has a short adult lifespan, sometimes only lasting a few hours to a couple of days. The purpose of the adult stage is primarily reproduction. They undergo an incomplete metamorphosis, which includes the egg, nymph, subimago (dun), and imago (spinner) stages.
- Nymph Stage: The nymphs are active swimmers and can be found in the fast currents of streams. They have a distinctive appearance with dark bodies and pale markings.
- Importance for Anglers: This species is of particular interest to fly fishermen because trout and other fish often feed on the nymphs and emergers. As such, there are many fly patterns designed to imitate both the nymph and adult stages of Isonychia bicolor.
- Appearance: Adults generally have a dark, mahogany-colored body. They are relatively large as compared to some other mayflies, making them easy to spot.
- Hatches: The hatches of Isonychia bicolor can be significant events on the streams where they occur, attracting many fish to feed. These hatches generally occur in late spring to early summer and then again in early fall.
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