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Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

Dorsal view of a Amphizoa (Amphizoidae) Beetle Larva from Sears Creek in Washington
This is the first of it's family I've seen, collected from a tiny, fishless stream in the Cascades. The three species of this genus all live in the Northwest and are predators that primarily eat stonefly nymphs Merritt R.W., Cummins, K.W., and Berg, M.B. (2019).
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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Stonefly Species Isoperla burksi (Yellow Sallies)

Species Range


Source: Taxonomic Notes On The Eggs Of Eastern Nearctic Isoperla (Plecoptera: Perlodidae: Isoperlinae)

Diagnosis. Szczytko & Kondratieff (2015) placed this species in the Isoperla burksi group with Isoperla cotta Ricker, 1952 and Isoperla orata Frison, 1942. Egg characteristics uniting these species include a concave cross-section, well-developed collar, distinct ridges off-setting the cell impressions, and lack of an eclosion line (Szczytko & Kondratieff 2015). Eggs of Isoperla burksi from Indiana and Kentucky, however, possess a distinct eclosion line (Figs. 4 - 6) that easily distinguishes this species from Isoperla cotta (Szczytko & Kondratieff 2015, figs. 10.14, 10.18) and Isoperla orata (Szczytko & Kondratieff 2015, figs. 37.9, 37.12). Each of the other three characteristics listed above are exhibited by Isoperla burksi.

Physical description

Most physical descriptions on Troutnut are direct or slightly edited quotes from the original scientific sources describing or updating the species, although there may be errors in copying them to this website. Such descriptions aren't always definitive, because species often turn out to be more variable than the original describers observed. In some cases, only a single specimen was described! However, they are useful starting points.

Source: Taxonomic Notes On The Eggs Of Eastern Nearctic Isoperla (Plecoptera: Perlodidae: Isoperlinae)

(Figs. 1 - 6) http: // lsid. speciesfile. org / urn: lsid: Plecoptera. speciesfile. org: TaxonName: 468714Source: Taxonomic Notes On The Eggs Of Eastern Nearctic Isoperla (Plecoptera: Perlodidae: Isoperlinae)

Egg. General shape oblong, cross-section concave (Figs. 1 - 2), anterior and posterior poles broadly-rounded (Figs. 2 - 4). Color pale brown. Collar well-developed, with irregular longitudinal ridges, slightly flared apically (Fig. 3). Follicle cell impressions near collar ranging from elongate to hexagonal (Figs. 1, 3). Chorion covered mostly with irregular-shaped pentagonal or hexagonal follicle cell impressions with thickened elevated ridges (Figs. 4 - 6); floors with numerous shallow pits (Fig. 5 - 6). Eclosion line present (Figs. 4 - 6). Micropyles located along ridges near eclosion line in anterior ¼ (Figs. 5 - 6).

Start a Discussion of Isoperla burksi


Stonefly Species Isoperla burksi (Yellow Sallies)

Species Range
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