This dun is smaller than would normally be expected for Drunella flavilinea, but it seems to fit the physical description of that species fairly well. I wasn't sure from the dun pictures alone, so I was hoping it would molt into a spinner. It never made it out of the dun's shuck, but it did begin the process, which allowed me with great care to tease out the last couple abdominal segments of the spinner from the still tightly attached dun shuck, enabling a more confident ID based on the shape of the spinner's penes and sub-genital plate. I also collected a nymph of flavilinea in the same river on the same evening, as well as a shed exuvium that looked large enough to belong to an emerging dun. The other possibility I considered for a while based on the dun was Drunella pelosa, which would be the right size, but the other characteristics don't fit.

A few days after unexpectedly collecting a female dun of this species, but in a sad, bedraggled shape, I went back to the same pool to see if I could find more. I was able to catch this one male dun during a dusk emergence dominated by other species, and he made it home in prime shape for photos.

I collected this female spinner with a male dun and a female dun of the same species.

A few of these nymphs turned up in my kick net sample, with this being the only one fully mature and ready to emerge. It keys pretty straightforwardly to Ameletus suffusus, particularly because of the triangular dark patch on the labrum. The abdominal markings are close but don't quite match other drawings, likely just individual variation.

Key characteristics verified under the microscope: -The head has 3 ocelli. -Maxillary palp has 5 segments, with the second segment rounded. In some of the pictures it looks like 6 with the 3rd segment rounded, but the basal "segment" in that case isn't part of the palp. -Foretibiae lack preapical spurs. -Pronotum with mesal setose warts widely spaced. All of this very clearly indicates Glossosomatidae. Beyond there: -The tibial spur counts (fore / middle / hind tibiae) are 2, 4, and 4. -From the pictures, the hind wing discoidal cell is closed, not open. Subfamily Glossosomatinae. -The upper and lower parts of the mesepisternum are separated by a constriction, not a transverse suture. Microscope picture included. This leads to a very confident genus ID of Glossosoma. I don't have the information to take it to species.

I collected this female dun with a male dun and a female spinner of the same species.

I collected this male dun with a female dun and a female spinner of the same species. Identification was initially difficult because I didn't catch a male spinner, and this dun was missing its legs. I was able to tease the spinner's penes out of the dun's shuck after it expired, although the shape was pretty similar. Fortunately, the shape is a distinctive match to the Epeorus albertae species group. In the key in Needham et al (1935), it keys to Epeorus youngi, which is now considered a synonym of albertae. It's also a very plausible dun version of this spinner collected a few years earlier, a few drainages to the north, at a similar time of year. Additionally, the female dun and spinner collected with this one match very closely those I've collected in the past.

This specimen keys pretty well to Cultus. Key characteristics observed under the microscope but not necessarily apparent on my photo are the lack of submental gills (or any gills at all), the lack of short, stout setae on the occiput or anterolateral prothoracic margins, and the lack of a low knob below the subapical tooth on the lacinia. Species known to be found in Washington are Cultus pilatus and Cultus tostonus. It clearly does not fit the description by Frison (1942) of Diploperla pilata, as Cultus pilatus was first named. I cannot find a detailed description of the nymph of tostonus, but Ricker 1952 describes a defining character of the adults, "Head mostly yellow, the only important dark marking being the bands which join the anterior to the lateral ocelli ; median pronotal stripe, at its middle, about one-fifth of the width of the pronotum." The nymph shows a very dark pattern fitting that description on the head (likely retained into adulthood) and the pronotal stripe is about the right width, too. Given that visual description, the range, and the poor fit to pilatus, I'm calling this Cultus tostonus.

This female spinner was collected with a male from the same swarm.

A couple days earlier I caught a male spinner of this species with some wing damage and missing tails, so I went back to the same pool try to get one more intact. This one has some leg damage, but between the two specimens you can get an idea what the whole insect looked like. There were small clouds of Cinygma dimicki spinners again over the same two small, specific locations in the pool, which is an interesting testament to how repeatably they choose their ideal mating habitat. I was able to capture this one and a female.

For details about the tentative identification of this male dun, see the page for associated male spinner, captured from a mating swarm in the same location and at the same time as this dun was emerging.

I collected numerous spinners from a thick dusk mating swarm and spinner fall over the Cedar River on a cloudy evening at the end of June. Duns were emerging at the same time, so I was able to collect several male spinners as well as a female spinner, a male dun, and a female dun of the same species, whatever it is. The microscope pictures here come from a mix of those different males, but all the macro DSLR photos are of the same individual. This one is difficult to identify, though I went into a lot of detail since I caught so many and their fall really got the fish rising for a while at dusk. The penes have a single set of lateral subapical spines, and the wings of the male spinner appear to be untinted, although there may be a barely-perceptible uniform yellow tint. The two claws at the end of each tarsus are similar to each other in shape. The wing is 7.5 mm long and the body is 7 mm long. I think these are the possibilities: 1. The best guess is Cinygmula tarda, which is the only species matching the size of this specimen in Needham et al (1935). The rest of the description seems to fit pretty well. However, the picture of the genitalia in that source and the one Slater & Kondratieff (2004) differ somewhat from each other and from this specimen, which more closely fits the drawing for Cinygmula mimus. 2. My next guess would be Cinygmula tioga. The original description in Mayo (1952) fits remarkably well, and it's only reported to be 1 mm longer than this specimen (within the likely range of natural variation). It hasn't been reported yet from Washington, only California and Oregon, but the sites in north-central Oregon aren't implausibly far from west-central Washington. However, the drawing of the penes suggests that the lateral spine should be longer or located closer to the tip than in this specimen, and that species is also supposed to have yellow-tinged wings. There may be a very faint tinge to this specimen, but it's hard to tell. 3. It could be either a species not yet described or an undescribed variant of a current species. And here's a quick list of why other local species were ruled out: mimus — This species is the best match for the genitalia, but it's supposed to be much larger with a wing length of 10-11.5 mm, and it should have clearer tinting to the wings in a particular pattern. However, Mayo (1952) notes that mimus should not have tracheations on the tergites, as this one clearly does, which would make it fit tioga. I'm not sure where tarda falls on that characteristic. Also, Slater & Kondratieff (2004) describe the compound eyes of mimus as contiguous, which doesn't fit this specimen. This specimen also has dark mid-ventral markings on the sternites, which mimus should lack. uniformis — wing length 10 mm, small ventral subapical spine on penes not present in this specimen, reticulata — wing length 9 mm, has distinctive wing patterning definitely not present on this specimen. par — wing length 9-10 mm, penes lack prominent lateral spines, generally shaped wrong, tarsal claws would be dissimilar in par ramaleyi — wing length 10 mm, penes shape way off gartrelli — wing length 10 mm, crossveins in costal half of forewing margined with brown (unlike this specimen), penes shape similar being in same group with mimus, but has an extra small spine not present in this specimen

I found a couple small (one or two dozen flies) clouds of these male spinners dancing low over the riffly parts of a pool in this fast river draining out of the Cascades.

For details about the tentative identification of this female spinner, see the page for associated male spinner, captured from the same mating swarm.

These duns were emerging sporadically throughout a cloudy evening at the end of June. Had I looked more closely when I caught this one and realized it represented my first collection of this genus, or just noticed the really striking coloration, I would have set my fly rod on shore and spent more time lurking mid-river with my net trying to catch more of them emerging (and at least one in better shape). It's always a bit difficult to identify a female dun, but in this case the three longitudinal stripes on the sternites are very distinctive and narrow the choices to Caudatella heterocaudata and Caudatella columbiella. However, the length of the fore wing measured with a caliper is 7.25 mm, whereas columbiella should be no more than 6 mm, so heterocaudata appears to be the correct ID.

For details about the tentative identification of this female dun, see the page for associated male spinner, captured from a mating swarm in the same location and at the same time as this dun was emerging.

This male spinner molted from a dun I photographed a few days earlier, as did a female of the same species that I captured with it. It keys confidently to Eurylophella temporalis using Allen & Edmunds (1963), primarily based on the shape of the penes, which is more distinctive for this species than for most others in the genus. However, the remainder of the description of the male spinner in that paper fits this specimen perfectly as well.

I found this specimen along with a female on the surface in the shallows of a long flat in a warm-water smallmouth bass stream, during the middle of the afternoon. There were quite a few of them on the water throughout the day, but not enough to interest trout, especially since the nearest trout were several miles away in different rivers. I held on to this one for a few days hoping it would molt into a spinner for a better chance at a positive species ID, and it finally did, so this same individual is listed as a separate specimen as a spinner.

This female spinner molted from a dun I photographed a few days earlier, as did a male of the same species that I captured with it.

I found this specimen along with a male on the surface in the shallows of a long flat in a warm-water smallmouth bass stream, during the middle of the afternoon. This same individual is listed as a separate specimen after molting into a spinner.

This female dun was kind of interesting, having a bit stouter proportions that I'm used to seeing. I forgot to photograph her against the measurement scale.