blue-winged olive, BWO (Great Britain)　 English　《insect》

　 A mayfly with bluish wings and an olive body, it is often abbreviated to BWO.　The mayfly called BWO differs in Britain and the United States, and this paragraph describes BWO in Britain.

　 It seems to stand for Ephemerella ignita in Britain.　This mayfly is a common species and is distributed widely over the whole country in Britain, Ireland, and Europe.　It has been recognized in fly fishing for many years in Britain.　It inhabits various sized rivers, lakes, also in high elevations.　Body length is about 9 mm, it hatches during evenings in June - October.

　 As an imitation of a dun, there are BWO Dun, Red Quill, and Orange Quill of Skues.　Because the body resembles the color of sherry wine (reddish cinnamon color), the female spinner is called sherry spinner.　The male spinner is of a similar color, but has a little darker body, and because they are few in numbers, it is not treated as important.　Making an imitation of a sherry spinner is said to be difficult, but, there are excellent fly patterns such as Orange Quill, Sherry Spinner made by William Lunn, and Rusty Spinner introduced by Skues.

【Reference】An angler's entomology, 1952.　Trout flies of Britain and Europe, 1991.　Nymph fishing for chalk stream trout, 1960 (1939).　Collins illustrated dictionary of trout flies, 1998 (1995).　The new encyclopedia of fly fishing, 1999 (1986).

→Ephemerella, Red Quill, Orange Quill, Sherry Spinner,