Here is a simple hatch chart for the Upper Credit River. As with any hatch chart, dates are approximate and may vary depending on the year, weather patterns and other factors. This chart is not meant to be exhaustive and has been purposely simplified to include only those insects that are of importance to the fly angler.

You can also view the full Credit River Insect and Fly Reference here.

¹ Includes both the larger Sulphur Dun (Ephemerella Invaria) and the later and slightly smaller Pale Evening Dun (Ephemerella Dorothea).
² Isonychia is easily the most prolific and reliable mayfly on the Upper Credit River.
³ Late Hex (Hexagenia Atrocaudata) is the later and slightly smaller cousin of the better known Hexagenia Limbata.

A number of insects that may be occasionally found on the river but do not generally have reliable hatches have been omitted. Terrestrials such as ants and grasshoppers have also been omitted, although they can still be productive on warm windy days in the summer and fall.