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This topic is about the Mayfly Genus Tricorythodes

A cult following is something to which few insects can lay claim, but the tiny Tricorythodes mayflies certainly qualify. Their widespread, reliable, heavy hatches draw impressive rises of ultra-selective trout which demand the most of a technical dry-fly angler's skills.

It is surprising that such a great hatch took so long to come to the attention of fly fishermen. The Tricos were first introduced to anglers in a 1969 Outdoor Life article by Vincent Marinaro, who misidentified them as Caenis. By the early 1970s the identification had been corrected but Swisher and Richards still wrote in Selective Trout, "Few anglers are familiar with these extremely small but important mayflies." The next wave of publications boosted Tricorythodes to its current fame. I suspect their early dismissal was due in part to tackle limitations; anglers in the 1950s had no means to effectively tie and present size 22-28 flies. Read more...

There are 7 more specimens...

The Discussion

SteamntroutSeptember 10th, 2021, 9:10 am
Posts: 5Recently I decided to tie up some trico soft hackle flies, and wanted to do as I have been for a while tie up Nymphs, emergers, and drys to have a better arsenal in my offerings.

I find very little on trico nymphs, and less for emergers.

Would really like to see some photos of the actual bug with actual measurements not hook sizes.
WiflyfisherSeptember 11th, 2021, 4:26 am

Posts: 663
I love the Trico hatch and try to fish it every year. I also try to study the insects as well. I have read the male Trico duns (all black body) hatch sometime during the night. The female Trico duns (olive body with black thorax) hatch in the early mornings. All my morning sampling seems to prove that correct.

The females than fly off to the grass or brush along the banks and molt into spinners. Then join the males in the clouds along the edge of the stream to mate and then fall on the water to lay their eggs and die.

I find the average size of the female dun's body to be 3-4mm long and the wings about 20% longer.

I have a much more difficult time hooking the trout during the female dun emergence than during the spinners on the water. Tiny nymphs and olive body emergers are tough to see. Plus, any micro-drag will put the trout down in my experiences. My most successful pattern during emergence has been an olive thread body, black dubbing thorax with gray CDC wing. I have tried several soft hackle variations and had little success.

When the trout are staying just under the surface and sticking their nose above to gulp in Trico spinners I find it much easier to hook the trout than during emergence. I often have found a size #18 Renegade works great than because I can see it and avoid drag and better placement of the fly to the trout's feeding lane. The trout are so busy gulping in spinners that it works well. I also tie a black body, thick thorax spinner using organza for the wing. It is super effective but tough to see on the water.

My preferred hook is a size #20 or #22 TMC 2488. It is 2x short and 3x strong. In my experience, the lightweight dry fly hooks often get straightened by the bigger trout. Plus, I need to keep the trout's head up to keep them from diving into the weeds.

Here are some recent photos from this year:

John S.
MartinlfSeptember 11th, 2021, 7:11 pm
Palmyra PA

Posts: 3233
Great photos. We have several Trico threads with other photos that can be pulled up with a few searches. I too am a Trico addict.
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
Brian314January 4th, 2022, 1:07 am
Fenton, MI.

Posts: 51
I learned something new about tricos a few months ago - apparently, the olive abdomen on the females will turn white after the eggs are deposited. I can't say I've ever actually observed this but I did tie up a few back in October (using white thread for the abdomen) and will try them in 2022. :-)
MartinlfJanuary 4th, 2022, 9:56 am
Palmyra PA

Posts: 3233
I use olive abdomens on my Trico duns (for females that hatch in the early morning; males hatch at night), and I tie some female spinners with white abdomens. Search "Trico" on Troutnut for other threads with lots of information.
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
PartsmanJanuary 4th, 2022, 1:51 pm
bancroft michigan

Posts: 420
Great pics John, and very informative post.
Thanks, Mike

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