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Hatches › Mayfly
Baetis · genus
A small, dependable mayfly hatch that keeps Idaho trout looking up in cool-weather windows.
Category
Mayfly
Category
The insect or forage category for this profile.
Size
Small; commonly imitated in the #16-22 range, sometimes smaller.
Size
Typical size range anglers imitate on the water.
Key stages
Eggs, Nymph, Emerger, Dun, Spinner, Egg Laying Spinner, Spent Spinner
Key stages
Life stages most relevant to fly fishing this hatch or forage.
Water types
Rivers, Streams, Spring creeks, Tailwaters
Water types
Water types where this bug or forage is commonly found.
Baetis is a genus of mayflies in the family Baetidae, commonly called Blue-winged Olives by anglers. With at least 150 described species worldwide and strong variety in North America, this is a broad hatch group rather than a single bug.
Also known as: BWO, Baetis
Female mayflies deposit hundreds to thousands of tiny eggs either in or near the water. These eggs then sink to the stream bottom to develop.
Nymphs reside on the stream bottom, where they feed and grow through a series of molts, spending the majority of their lives underwater.
The nymph actively swims to the water's surface, where it begins the crucial process of emerging into its adult form.
After emerging, the freshly hatched adult, known as a dun, rests briefly on or just above the water's surface before flying off.
Matured duns molt into spinners, which are the sexually reproductive adult stage. These spinners take to the air for mating.
After mating, the female spinner returns to the water's surface to deposit her eggs, initiating the next generation.
Having completed their reproductive cycle, the adult mayflies die, often floating dead on the water's surface, a common sight for anglers.
nymph
Savage Flies
Materials
emerger
tightlinevideo
Materials
dun
Fly Fish Food
Materials
spinner
Holsinger's Fly Shop
Materials
Egg Laying Spinner
East Rosebud Fly & Tackle
Materials
Spent Spinner
troutcastz
Materials
Blue-winged Olive
One species, multiple rivers.
