Dark Fishfly

''Nigronia serricornis'' has many common names including; hellgrammites or fishflies or saw-combed fishfies. The genus ''Nigronia'' has one other North American member ''N. fasciatus'' which lives in much of the same territory and is quite similar in all regards. They are holometabolous insects with an aquatic larval stage. ''N. serricornis'' is a common inhabitant of woodland streams in North America and they are often the largest insect predator found in 2nd and 3rd order streams. The larvae are a sit-and -wait ambush predators that feed on a large variety of invertebrates. Studies have shown that ''N. serricornis'' has a varying diet throughout the seasons.