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Closeup insects from the Fall River

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Female Lepidostoma podagrum (Little Brown Sedge) Little Brown Sedge AdultFemale Lepidostoma podagrum (Little Brown Sedge) Little Brown Sedge Adult View 3 PicturesThese specimens are still alive, just very cold, so the colors are accurate. I put them in the freezer for a bit to settle them down and overdid it a little:)
Collected May 12, 2011 from the Fall River in California
Added to Troutnut.com by Entoman on December 14, 2011
Female Anafroptilum album (Tiny Sulphur Dun) Mayfly DunFemale Anafroptilum album (Tiny Sulphur Dun) Mayfly Dun View 3 PicturesApprox. 5 mm. This is a very significant hatch. It is mostly seen at the height of Summer and I was very surprised to see it emerging this late in the season and in such numbers. When this one is emerging, the fish can become quite selective.
Collected November 9, 2011 from the Fall River in California
Added to Troutnut.com by Entoman on December 10, 2011
Female Paraleptophlebia debilis (Mahogany Dun) Mayfly DunFemale Paraleptophlebia debilis (Mahogany Dun) Mayfly Dun View 3 PicturesSize: 9mm. These photos really highlight the brown pigmentation of the wing venation (Venation: The pattern in which the veins on the wings of an insect are arranged. It is usually one of the most useful identifying characteristics.), but in the hand the wings look to be a uniform smokey gray. - Entoman
Collected October 22, 2011 from the Fall River in California
Added to Troutnut.com by Entoman on February 4, 2012
Female Ephemerella excrucians (Pale Morning Dun) Mayfly DunFemale Ephemerella excrucians (Pale Morning Dun) Mayfly Dun View 3 PicturesSize: 10mm. At emergence the specimen was a fairly bright olive green and there was obvious difference in color between the forewing (med. dun) and the hind-wing (pale cream). It was really noticeable as they floated by. You can just make these features out in the second photo, but not so much in the first that was taken 24 hours after capture. Total time from emergence to molting - approx. 48 hours.

Entoman


Edit 2/25/13 - This specimen was originally posted to E. d. infrequens because of its size. It turns out large size doesn't hold up as a way to tell these two apart. This is because excrucians has much greater variability than previously understood. The assumption by anglers that excrucians is always the smaller of the two is apparently not supported by science. There is a lot left to sort out with western Ephemerella species. This may include new discoveries and/or synonyms (Synonym: A former name of a taxon, usually a species. Entomologists frequently discover that two insects originally described as different species are one in the same, and they drop one of the names. The dropped name is said to be a synonym of the remaining name. These changes take a while to trickle into the common knowledge of anglers; for example, Baetis vagans is now a synonym of Baetis tricaudatus.) as well as reportage on new intraspecific variations broadening the descriptions of recognized species. Based on this specimen's Fall maturity, the best guess is that it is an unusual form of excrucians.

As to color, both species duns (nymphs too) demonstrate a tremendous amount of intraspecific variability from pale yellow to bright green with a multitude of sulfur shadings in between, ranging from pale amber, through orange to cinnamon and even dark brown. I've seen wings from pale cream through tannish and almost every shade of dun except the dark shades. Some have pigment stained leading edges matching their bodies, some don't. Most of these variations are undocumented except in angler references and periodicals. It seems a rare year that a new variation doesn't pop up to the notice of anglers.

Bottom line - size is only reliable if the specimens are smaller than size 16, pointing to excrucians. Otherwise, the only fairly dependable way to tell them apart (especially the females) is by timing as infrequens is the first of the two to appear, rarely lasting longer than a couple of weeks or later than the end of June most years. The problem with using timing for determination is it requires knowledge of the hatch sequences as they actually occurred for a given year on a given piece of water. Obviously, this kind of information is seldom available. Without it, determining between the two duns if they are larger than size 18 is speculative at best - at least until very late in the Summer.
Collected October 16, 2011 from the Fall River in California
Added to Troutnut.com by Entoman on October 21, 2011
Lepidostoma podagrum (Little Brown Sedge) Little Brown Sedge LarvaLepidostoma podagrum (Little Brown Sedge) Little Brown Sedge Larva View 2 PicturesThe photo of the specimen cased is alive. The photo of the uncased larva is the same specimen taken after it was preserved in its case. Unfortunately, there was a lot of pigment transfer making the specimen look olivaceous. In life it was grayish white as shown in the first photo.
Collected May 12, 2011 from the Fall River in California
Added to Troutnut.com by Entoman on December 14, 2011
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