Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

> > Lepto question

This topic is about the Mayfly Family Leptophlebiidae

The champions of this family are Leptophlebia and Paraleptophlebia, along with the relatively newly-defined genus Neoleptophlebia containing several important species that were once in Paraleptophlebia. The large mayflies of Leptophlebia are on the water sporadically for a long time. The Paraleptophlebia and Neoleptophlebia flies are smaller but come in much more concentrated numbers.

Leptophlebiidae also contains several genera and species which are never mentioned in fly-fishing literature, either because they are too rare or because they require water too warm for trout.

There are 60 more specimens...

The Discussion

JasonMMarch 7th, 2010, 12:18 am
Prescott, AZ

Posts: 1
I live in Arizona and I have a question...

Over the past several years I have witnessed a spectacular emergence of mayflies on a stream I frequent in the Mogollon Rim area of Arizona. The stream is a tributary to the Little Colorado River drainage.

The adults seem to emerge on exposed midstream rocks of along the shoreline. The duns can be very dense, sometimes every rock along shore has one drying its wings beforetaking flight They are a dark greyish brown bodied, dark grey winged adult, I have named them MOCHA DUNS for lack of knowledge of their true identity. Three tails on the adult as well. They are pretty big....a big size 14 to 16. I have captured several specimens as larvae that I believe are the same species as the ones I have observed as adults. The larvae have prominent gills. 3 long split tails, similar size and color, hign densities along shore and in the shallows, etc. I'm 90% sure that they are Leptophlebiidae. But I don't know the species, yet.

The trout don't seem to key in on the adults...since they emerge on land...but I have experienced some incredible fishing during very windy days while the hatch is on. The nymphs appear to have trouble holding on to the substrates they are trying to emerge on. I have witessed several swimming to a streamside cobble, grasping the rock for a moment, only to be swepped back into the water by small, lapping waves being caused by the wind. They try repeatedly but seem to get exhausted pretty quickly. They must be easy picking for fish cruising along the bank, as I have great success fishing imitations along the shore with short twitches. I have rarely seen duns on the surface of the stream, even on the windiest of days. They seem to emerge late morning to early afternoon.

CAN ANYBODY SUGGEST WHAT SPECIES THIS MAYBE. I don't have a scope or any literature anymore. I have experience with ID'ing but not lately

Any help would be appreciated by this inquisitive angler. Thanks

Jason Mszaros
The Drag Free School of Fly Fishing
TaxonMarch 7th, 2010, 12:45 am
Site Editor
Royse City, TX

Posts: 1350

What month of the year does this emergence seem to peak?

If it's some time between mid-June and mid-July, my guess would be Paraleptophlebia memorialis.

Here is a detailed description:

Family: Leptophlebiidae
Scientific name: Paraleptophlebia memorialis

Previously know as: Leptophlebia memorialis, Leptophlebia pallipes (in part), Paraleptophlebia pallipes
Common name: Mahogany Dun, etc.
Locality: W
CAN Regions: NW
MEX Regions: SW
USA Regions: NW, SW
Cent. Amer. Countries:
CAN Provinces: AB, BC.
MEX States: BN.
USA States: AZ, CA, CO, ID, NM, OR, SD, UT, WA
Emergence (begin) date: mid-Jun
Emergence (end) date: early-Aug
Emergence time of day: afternoon
Spinner fall time of day:

Nymph minimum length: 6 mm.
Nymph maximum length: 7 mm.
Nymph identification keys: gill fork 1/3 from base; abdominal spines on segment 8 & 9; tergites dark, each w/three light dots, a medium-sized one on center-line, and a small-sized one forward on each side of center-line
Nymph body description:
Nymph legs:
Nymph gills: gill/filament length ratio (1:3), trachael branching: (absent)
Nymph tusks: absent
Nymph tails: 3,

Dun minimum length: 6 mm.
Dun maximum length: 8 mm.
Dun identification keys:
Dun body description: brown to dark reddish brown
Dun wings: medium gray, hind wings w/o costal angulation
Dun legs: brown
Dun tails: 3, light to dark brown

Spinner minimum length: 7 mm.
Spinner maximum length: 7 mm.
Spinner identification keys: male claspers w/3 joints
Spinner body description: abdomen whitish
Spinner wings: hyaline, fore wing with attached intercalaries, hind wing w/o costal angulation
Spinner legs:
Spinner tails: 3,

Best regards,
Roger Rohrbeck

Quick Reply

You have to be logged in to post on the forum. It's this easy:
Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.

Related Discussions

TitleRepliesLast Reply
Re: Unidentified Baetidae
(2 more)

In the Identify This! Board by Benthosfan
8May 5, 2021
by Benthosfan
Re: Little White Mayfly
In General Discussion by Lastchance
6Aug 1, 2009
by Taxon
Re: Emerger
In the Mayfly Genus Serratella by Martinlf
6Jun 11, 2009
Re: Thoughts
In Male Eurylophella Mayfly Spinner by Taxon
5Mar 7, 2013
by Entoman
Re: Mayfly from Chalk stream
In the Identify This! Board by Stanislav
12May 4, 2007
by Taxon
Re: does color=species?
In the Mayfly Family Ephemerellidae by CaseyP
5May 2, 2008
Re: White Mayfly ---- Euphron leukon?
In the Identify This! Board by JumpNotZero
1Sep 9, 2008
Re: can you identify this bug?
In the Identify This! Board by Wchougland
1Jan 12, 2021
by Troutnut
Distance between the eyes of male Epeorus
In the Mayfly Genus Epeorus by Troutnut
Re: Turkey Feathers
In Fly Tying by GldstrmSam
3Sep 24, 2012
by GldstrmSam