Help ID this Olive

clwydspecial

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May 1, 2008
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Denbigh
I have been on another forum's entomology page and its suggested its a "Large Dark Olive female dun (Beatis rhodani)" mainly due to the time of the year as no other true olives about this early season.
 

phl

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Dec 30, 2009
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Knaresborough
Yes, Large Dark Olive is likeliest at this time of year. However, there are lots of very similar flies; for example, it could be a (rather early) Pond Olive (Cloeon Dipterum). Do you have a pond in your garden? I used to get Pond Olives in mine. The Large Dark Olive, and all the other Baetis Olives, have very small hindwings, but these are hard to see without a close inspection - I couldn't be sure from your (excellent) pics. It's not a March Brown, however, which has mottled wings.

Paul
 

clwydspecial

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Joined
May 1, 2008
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Denbigh
I'll see if any of the other pics show a hind wing, there is a garden pond about 7 doors up but there is a small muddy stream about 30 mts away so it's probably from there.
 

phl

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Dec 30, 2009
Messages
427
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Knaresborough
Yes, definitely Large Dark Olive, I'd say.
The Baetis Olives: Large Dark Olive, Small Dark Olive, Medium Olive, etc, are very difficult to tell apart; they all look pretty much like the fly in your photographs. "Dark", Medium", etc doesn't mean much: even the Small Dark Olive is sometimes described as a "Pale Watery", and the size differences are not great. However, the Large Dark is much the most likely at this time of year, and is very widespread.

BTW, I don't want to pose as an expert; I like trying to work out what fly is hatching, but I'm really not much good at it!

Paul
 
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