The Other Mayfly in Trout's Menu

So Pale Morning Dun (click for details)hatch is still strong on spring creeks in Livingston. Various hatching stages of PMD are definitely main dish for trout. But also, the more I fish, the more I "learn & observe". As I conduct stomach-pumping, I have been finding a certain amount of another mayfly species. It's still considerably minor compared to PMD but as long as certain number of trout are keying on, I can't ignore. And I have developed fly patterns matching for spring creeks!!
Let's see my PMD patterns first.

Sawyer PT - Master Angler Version is the staple among staples.

My own Pheasant Tail Mayfly Cripple.

And this is the other species that has been ticking my mind and imagination; Mahogany Dun (click for details).

As you can see in the link, Mahogany Dun nymphs have distinctive abdomens. Then over all silhouette is thinner than PMD nymphs. So I modified Sawyer PT a bit.

I also adjusted Pheasant Tail Mayfly Cripple into Mahogany Version, that I like it myself!

At Livingston's spring creeks, size 18 is what's mostly seen.
Again, PMD hatch is the most important and that's what you should fish for. But if you want to add some spices on your days, or if you happen to observe Mahogany Dun are taken over PMD, then tie some on!