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Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

Lateral view of a Male Callibaetis ferrugineus (Baetidae) (Speckled Dun) Mayfly Spinner from Mystery Creek #304 in Idaho
This is one of four specimens I photographed together from the same hatch, also including a nymph, a male dun, and a female dun. According to the key in Check (1982), the clear wing venation on the associated dun shows that it is either Callibaetis ferrugineous or Callibaetis pallidus, and the characteristics to tell the difference between those two are maddening for both the nymph and adult. If the partial shading in the wing is "medium to dark brown," and the dots on the body are "fuscous to dark brown," then it's ferrugineous. If the wing shading is "chestnut brown" and dots on the body are "yellowish to chestnut brown," then it's pallidus. However, several spare specimens I collected alongside the one in the photo have no markings on the wing at all, which would seemingly indicate ferrugineous according to the key. It's enough for a contingent ID, but I still wouldn't rule out pallidus.
27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
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Dorsal view of a Stenacron interpunctatum (Heptageniidae) (Light Cahill) Mayfly Nymph from the Marengo River in Wisconsin
Posts: 1
Chadwick on Jul 1, 2009July 1st, 2009, 12:19 pm EDT
I would like to know the best way to present the nymph and in which section of the river. Should they be dead drifted mid riffle, swung through tail out ect.
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"Bear Swamp," PA

Posts: 1681
GONZO on Jul 2, 2009July 2nd, 2009, 11:12 am EDT
Hi Chadwick,

Although heptageniids can swim, they generally do it out of the current. If you were to rate the swimming ability of mayfly nymphs, Isonychia would be Michael Phelps, and most heptageniids would be something like the fat kid in remedial gym class. When you watch heptageniids like Stenacron, Maccaffertium, or Stenonema in aquaria, they often try to cling to airstones or, in the absence of stones or other debris, to each other. However, when they get caught in the turbulence created by the airstone without first getting a good grip, they usually freeze and drift in a kitelike manner until they are free of the current. Then they might swim around awkwardly until they regain a foothold on something.

So, clinger nymph imitations presented in stronger current should usually be dead-drifted with at most an occasional feeble twitch. A gentle twitching lift or swing would be imitative as the nymph moves into emergence sites near edges, eddies, or slack areas around boulders.

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