Big Yellow May
Big Yellow May
Family: Ephemeridae
Genus: Hexagenia
Life Cycle: incomplete
Three Life Stages: egg, nymph, adult cycle which includes 2 phases: dun and spinner
Emergence: May-August
Burrower Mayfly Group
Nymph
Body Description
Antennae: 2, short
Head: tusks on head: rounded projection at front of head
Eyes: large
Tails: 3
Wings: pads
Gills: use to circulate throughout their burrows
Legs: 6
Body Colors: pale yellow-brown
Mobility: dig U-shaped burrows
Size: 18-35mm
Hook Size: 6-8, 3X Long
Largest Mayfly. They live in streams and lakes where they can have firm bottoms to dig burrows.
Dun
Body Description
Antennae: 2, short
Eyes: 2 large
Tails: 2
Wings: 2 sets, no marks on them but well veined
Legs: 6
Body Colors: top, light tan to bright yellow with distinct dark markings; bottom, unmarked lighter shade of top
Mobility: are not fast emergers
Size: 22-35mm
Hook Size: 6-10
Spinner
After spinners emerge they mate high above the water. This takes place in flight. After this process the male falls spent to the water and the female returns to lay her eggs, and then falls spent to the water. Trout like all stages of the Big Yellow May but the spinner is least important to the angler.