Trout love the blue winged olive mayflies because they tend to hatch in large numbers, and the dun rides the surface water for a long time, making them great dry fly food for trout and a great pattern to have in your fly box. The BWO won’t disappoint.
The general colour for this dry fly is an olive-brown body with a whitish-blue wing and greyish-blue hackle fibres. They can be tied in various sizes, from a size 14 down to a small size 18 fly. Size 16 is the most common size fly to fly fish with.
- Hook: size 12 – 18 standard dry fly hook
- Thread: Griffiths Sheer thread olive or white 14/0
- Wing: Cookshill white CDC
- Tail: Cookshill Coq de Leon feather
- Body: Hareline, olive hairs ear dubbing
- Thorax: Any good quality grizzly hackle fibres
Check out our recommendations for the best fly tying kit if you’re looking to get started here.
How To Tie a Blue Wing Olive Step-by-Step
Lock your hook in the vise, making sure it is secure and not too close to the tip of the jaws, as the hook may slip when you apply tension to it. I advocate using barbless hooks where possible to ease the removal and minimise the damage done to the fish.
Start by tying a good thread base on your standard dry fly hook. Finish with your fly tying thread 2/3 up your hook shank.
For the wing, take two white or grey CDC feathers and lay them on top of each other. This is the traditional way of tying these fly patterns; sculpting fibre or poly yarn can also be used for the wing. This style of dun can also be tied in an Adams style of fly where the wing becomes more of a post. The post steps can easily be found if you search a site shop or two for a few videos.
Pinch wrap the two CDC feathers on top of the shank and tension the tying thread. Gently with your left hand, pull the feather stems until the feather tips are at the correct length for the wing. I generally like a slightly longer wing, so the hook shank length is a good guideline. Once you have your length, secure it with a few wraps and trim off the excess.
Taper the body back towards the tail area.
Tie in the tail with a few Coq de Leon fibers. Spend some time now to get a nice body profile for your pattern.
Start a dubbing thread with your body olive dubbing for the abdomen and wrap forward until just behind the CDC feather.
Wrap back slightly, creating a thread base for the hackle to be wrapped on tightly.
Tie in your feather, making sure the hackle fibers are roughly the same size as the hook gape. Wrap your thread forward, stopping behind the hook eye.
With your pliers, wrap the hackle forward, making sure you don’t trap any hackle fibers. Secure the hackle and create a good head, and whip finish the pattern. You want the hackle tips to be shorter than the wing and prop the wing up and slightly forward.
Summarized step but a step for the bwo
- Secure hook and wrap a good base.
- Tie in your wing.
- Make your tail, using the hook shank as a guideline for its length.
- Wrap the olive body dubbing forward.
- Tie in your hackle and wrap forward.
- Secure the hackle and whip finish.
What Is a Blue Winged Olive Fly?
The Blue Winged Olive (BWO) cleverly imitates the Baetis family of mayflies, with an olive-colored body and wings in shades of dun or blue.
It’s a small but important fly that rides high in the water and is extremely tempting to trout and other fish. In fact, the BWO deserves a spot in every fly angler’s fly box due to its versatility and reliability.
What Is a Blue Winged Olive Hatch?
A Blue Winged Olive hatch refers to when the Baetis mayfly is hatching in large numbers. The trout go crazy for these emerging mayflies as they rise up through the water column.
They may even refuse to eat anything else and will selectively eat just these insects during the hatch. This means that it’s an excellent time to crack out your Blue Winged Olive patterns, tie them on, and catch some fish.
The Baetis mayfly tends to hatch during the warmest parts of the day, between 10 am and 3 pm. It’s not always easy to tell when a Blue Winged Olive hatch will occur, but it is mainly triggered by the water temperature and barometric pressure.
See also our post on Barometric Pressure and Fishing to understand how barometric pressure affects fishing.
Most hatches happen when the water is between 40-44 degrees F. If you are fishing during a mayfly hatch, you won’t go wrong with your Blue Winged Olive patterns and will take home an impressive haul.
Where To Fish the Blue Winged Olive?
The Baetis mayfly is found in streams, creeks, rivers, and lakes all over the US and even worldwide, so it’s not hard to find a suitable spot. Just set up your fly rods, fly reels, fly lines, and tie on a Blue Winged Olive, and you’re all set.
Blue Winged Olive flies perform well on fast-flowing, choppy water. If you’re heading out to a riffly, lively stream or river and want a fly that will ride high on the water, the Blue Winged Olive makes an ideal choice.
You can fish the Blue Winged Olive all throughout the trout season so long as it’s not icy where you live. Many fly fishermen use the Baetis pattern from September through to April. They perform excellently on any trout stream in the country and are dependable flies to take on trips further afield, too.
How To Fish Blue Winged Olives
When you’re fly fishing a Blue Winged Olive, success lies in reading the water, making an accurate cast, and then achieving a natural drift. Ideally, you want to get your Blue Winged Olive very close to the trout and then just drift it gently and naturally past.
During a mayfly hatch, it’s essential to select the right size Blue Winged Olives to fish. When there’s so much forage available for the trout, they are very fussy and selective.
Fly fishing with the right size of fly will make all the difference in the number of fish you catch. Our top tip is to take a range of different size Blue Winged Olives with you on fly fishing trips, so you’re prepared for every possible situation.
You’ll also need to make repeated, precise casts and then aim to slowly drift your Baetis dry flies past any lurking trout looking for an easy and tasty bite. It’s commonly known that trout like to conserve their energy, so they won’t move further than they have to – especially when there are emerging mayflies in abundance.
Perfecting your cast and presentation is critical here, or the trout just won’t be interested. They can quickly spot an artificial fly if your presentation is lacking, and will steer clear. Spend some time working on the accuracy of your cast and a lifelike, natural presentation, and you’ll catch way more fish.
When do you get a strike, take care not to set your hook too quickly, or you will risk losing the fish. Allow yourself a little bit more time before you haul that fish in, tricky as it may be, and you won’t regret it!
The Wrap Up
So there you have our complete guide to the Blue Winged Olive pattern. The Blue Winged Olive is a popular among many anglers, and it’s a reliable choice to take on your fly fishing trips anywhere in the US. The Baetis mayfly is found all over, and this fly pattern will be sure to bring you plenty of success.
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