Mayfly Genus Cinygmula (Dark Red Quills)

This dun hatched out from a nymph in my aquarium on July 16th, after being collected July 10th. It is probably of the same species as this nymph, and this dun which also hatched from one of these seemingly identical nymphs.

I'm calling this one Cinygmula just based on the general look and the fact that the genus is very common in this river. Official keys can't rule out other Heptageniidae, though.

This female dun emerged from a creek loaded with mature Cinygmula nymphs including this specimen, so they're probably the same species. Unfortunately there aren't species keys for either stage.

This dun is almost certainly of the same species as this nymph, as it hatched in my cooler from a nearly identical nymph.

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.

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

This male was collected from the same cloud of spinners as this female and is probably the same species. I'm tentatively calling them both Cinygmula for now, but I'm really not sure about that ID yet.

The lengths of the wing and body, measured with a caliper, are both 8 mm.

Keys in Needham's 1935 Biology of Mayflies point to either Cinygmula reticulata or Cinygmula gartrelli. It seems to have crossveins in costal half of forewing only, slightly margined with brown and wings tinged with amber at base and along costal margin of both wing (gartrelli) as opposed to all crossveins of both wings faintly but broadly margined with pale smoky and wings entirely amber-tinged (although there is a slight amber tinge throughout, just more pronounced in places) as in reticulata. However, wing length reported for reticulata (9 mm) is closer to this specimen than gartrelli (10 mm). Ventral median marks are supposed to be "traces" for reticulata and "present" for gartrelli. Descriptions for both species involve semi-hyaline anterior abdominal segments not present on my specimens. Distribution records suggest reticulata lives nearby, so I'm going with that, but I can't confidently rule out gartrelli.

This specimen was collected from a swarm with a female and another male.

This spinner came from one of those huge swarms that make one just stop fishing and admire the spectacle. Not bad for a little-known species.

In the same swarm I collected a female and another male.

I'm unsure of the ID on this one; keys put it closest to Cinygmula reticulata, but I'm very doubtful of the species and not positive on the genus. Epeorus is another possibility, but I don't know which species it would be.

This one was collected in association with a female dun probably of a different family.

This one was preserved in ethanol and partially dissected, so it doesn't have its natural wild coloration, and it's missing some appendages. I'm posting it for identification purposes.

Male Cinygmula mimus spinner trapped in its subimago skin, a cripple??

Adults were collected from the North Fork of the Touchet River at Touchet Corral, 21 Sept. One photo is the swarm of males over the stream about 3 PM, air temp about 66 degree.

This female was collected from the same spinner cloud as this male.

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

This female spinner was captured in a swarm with this male and this other male, allowing for identification.

Unfortunately there's no good key to species of Cinygmula nymphs and I didn't find an adult, so this one will have to stay at genus level.

This one doesn't have the protruding mouthparts typical of Cinygmula, but I think it's just an oddball individual.

This nymph was one of many I collected with vivid white or semi-transparent markings on the front of the head, the sides of the pronotum, and the last abdominal segments.

This very strange nymph appears to be undoubtedly Cinygmula, yet it lacks the telltale protruding mouthparts that usually make that genus so easy to identify.

This nymph is almost definitely the same species as this dun, which hatched from a nearly identical nymph from the same collection.

This nymph is missing a few gills, but is otherwise in good shape. It was the only one of its species which turned up in my sample.

I had heard reports of a bright red heptageniid nymph before but never seen one until I found this early instar specimen in a very high water quality small stream in the Catskills.

I collected several live specimens of nymphs and reared them to the imago stage. They were C. reticulata. The interesting thing is they were collected in May and were emerging along with Rhithrogena (March Brown). This seems to be an overlooked hatch since in some rivers it emerges very early, before runoff.