Maccaffertium vicarium or the March Brown mayfly is a major hatch throughout the U.S. In the East and Midwest this hatch usually occurs from early May into late June. Formerly known as stenonema vicarium, concentrated March Brown spinner falls occur in the late evening towards dusk. See also; emerger, comparadun, cripple, and March Brown Set. Tied on a Daiichi 1190 (or TMC 100) barbless, or a Daiichi 1180 barbed chemically sharpened hook.
