Blue-winged Olive flies is a collective term used by
anglers in
fly fishing to identify a broad array of
mayflies
Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the order ...
having olive, olive-brown bodies and bluish wings in their adult form. Sometimes referred to as BWO , a wide array of
artificial flies
An artificial fly or fly lure is a type of fishing lure, usually used in the sport of fly fishing (although they may also be used in other forms of angling). In general, artificial flies are an imitation of aquatic insects that are natural food of ...
are
tied to imitate adult, nymphal and emerging stages of the aquatic insect. While the family
Baetidae
Baetidae is a family of mayflies with about 1000 described species in 110 genera distributed worldwide. These are among the smallest of mayflies, adults rarely exceeding 10 mm in length excluding the two long slender tails and sometimes muc ...
probably has the most species identified as blue-winged olives, another mayfly family
Ephemerellidae
Ephemerellidae are known as the spiny crawler mayflies. They are a family of the order Ephemeroptera. There are eight genera consisting of a total 90 species (Merritt & Cummins). They are distributed throughout North America as well as the UK. T ...
also contains some. Collectively, blue-winged olive mayflies are an important food source in most trout streams, thus their widespread imitation by fly tiers.
History
The first mention of Blue-winged Olive as common name may be in
Frederick Halford's ''Dry Fly Entomology'' (1897). Halford's Blue-winged Olives were identified as members of the genus
Ephemerella
''Ephemerella'' is a genus of spiny crawler mayflies in the family Ephemerellidae
Ephemerellidae are known as the spiny crawler mayflies. They are a family of the order Ephemeroptera. There are eight genera consisting of a total 90 species (M ...
. Both Alfred Ronald's ''Fly-Fisher's Entomology'' (1837) and Mary Orvis Marbury's ''Favorite Flies and Their Histories'' (1892)
do not refer to any flies as Blue-winged Olives. There is ample evidence in fly fishing literature that what are now called Blue-winged Olives were once called Olive Duns, Blue Duns, Iron-blue Duns, Olive Quills, etc.
General description
Swisher and Richards' ''Selective Trout'' (1971) gives the following description:
[ ]
List of Blue-winged Olive patterns
Adult patterns
Duns
Spinners
References
{{DEFAULTSORT:Artificial Fly
Fly fishing