Hex Mayflies
Hexagenia limbata
The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
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Mayfly Family Baetidae (Blue-Winged Olives)
"These little critters supplant the importance of many other well-known mayfly hatches."
-Fred Arbona in Mayflies, the Angler, and the Trout
Arbona did not overestimate these critters. Their great numbers and multiple broods each season make up for their size, which is rarely larger than size 16 and often smaller than size 20.
Hardly mentioned in angling literature prior to the middle of the last century, baetids have become increasingly important to anglers, rivaling any other family of mayflies in this regard. This is largely due to the extension of fishing seasons that now include the early and late periods when this family’s species usually dominate hatching activity. Another important reason is the tremendous improvement in tackle allowing more practical imitation of these little mayflies. The dramatic ecological changes in many of our watersheds and the subsequent impact this has had on the makeup of taxa populations is also a factor.
Common baetid hatches with a national distribution are the species Acentrella turbida, Baetis brunneicolor, and Baetis tricaudatus. In the West, Baetis bicaudatus, Diphetor hageni and Plauditus punctiventris can also be common. In the East and the Midwest, look for Baetis intercalaris and Plauditus dubius. The species Iswaeon anoka is important in both the West and Midwest. Some of the Procloeon and Anafroptilum (previously Centroptilum) species are coming to the increasing notice of anglers across the country.
Stillwater anglers are likely to run across Callibaetis ferrugineus ferrugineus in the East and Midwest. Western anglers will find Callibaetis californicus and Callibaetis ferrugineus hageni to be very important.
Streamside identification of these mayflies to the level of genus, let alone species, has always been difficult. It's a very rare angler who can correctly proclaim a mayfly to be "Baetis" at a glance and be right on purpose, rather than making a lucky (albeit likely) guess at that genus versus the many others in the family. This is now even more so as new taxonomic evidence has shown hind wing conformation (or lack of hind wings) and other features are less dependable as ways to tell the genera apart. Many of the lesser-known species probably produce excellent local hatches but have not caught enough attention to be properly recognized by anglers. The lesson is that we should not assume anything about the identity of many Baetidae hatches we come across; they may not even be in the Baetis genus, let alone familiar species.
Taxonomic History
Taxonomically speaking, this is an unruly family. The entomological community seems to be perpetually reclassifying its genera and species to the chagrin of many anglers. These changes are not capricious. The reason is older nomenclatures haven't provided the taxonomic flexibility required as more becomes known about the complexities of baetid relationships. Classification of this family’s genera and species is very much a work in progress. The changes have been so extensive that it is beyond the scope of this hatch page to track the taxonomic history effectively without interjecting even more confusion. If you are frustrated by the inability to find some of the old familiar names, you're not alone. Rest assured these popular hatches are listed here, just under the latest classifications. The old famous names are referenced in their hatch pages.
Where & when
In 981 records from GBIF, adults of this family have mostly been collected during June (25%), July (24%), August (15%), May (12%), April (8%), and September (7%).
In 1450 records from GBIF, this family has been collected at elevations ranging from -66 to 29016 ft, with an average (median) of 2854 ft.
Family Range
Hatching behavior
The Baetidae mayflies are so important, in part, because their life cycles include several points of unusually high vulnerability to trout. They emerge on the surface, and the nymphs may drift just under it for a while before breaking through. They have trouble escaping their shucks in the film, taking a long time and often becoming stuck in the process. Those which do escape may ride the water for quite a distance before taking flight.Nymph biology
The fast-swimming Baetidae nymphs are an important trout food even during non-hatch periods. The popular Pheasant Tail Nymph pattern, in small sizes, imitates them fairly well.Identification
To determine whether a specimen of Ephemeroptera belongs to Baetidae, use the Key to Families of Mayfly Nymphs or Key to Families of Mayfly Duns and Spinners.
Specimens of the Mayfly Family Baetidae
10 Male Duns
This dun molted most of the way into a spinner (though the wings got stuck) the evening after I photographed it, so I took some more photos of the spinner.
I found a female nearby, probably of the same species.
I found a female nearby, probably of the same species.
This is one of four specimens I photographed together from the same hatch, also including a nymph, a female dun, and a male spinner.
This male was associated with a female of the same species.
This specimen emerged indoors from nymphs I had collected, then partly molted into a spinner but got stuck along the way. I've included a couple pictures showing some of the spinner colors. It got a bit waterlogged after emerging, so the wings aren't in perfect shape, but it still represents one of two Baetids that were emerging and drawing trout to rise on the Yakima. Based on body size and shape, it is most likely the same species as this nymph.
This ia a very tiny (hook size 22-24) dun. The pictures are terrible, but it's very fragile and it's one of the first adult mayflies I ever photographed.
This dun emerged from a mature nymph on my desk. Unfortunately its wings didn't perfectly dry out.
15 Female Duns
This dun emerged on my desk from a container of nymphs I was sorting, so I was able to get an ID from the nymphs. I also uploaded photos of a female nymph and a male nymph.
This female was associated with a male of the same species.
This dun of a fairly large Baetidae species was one of only a couple I saw all evening.
I found this female in the same area as a male with similar markings, probably of the same species.
This specimen was collected on the same trip as a similar dun.
This specimen was collected on the same trip as a similar dun.
This little early-season dun molted into this spinner after I photographed her.
This is one of four specimens I photographed together from the same hatch, also including a nymph, a male dun, and a male spinner.
This one emerged from a nymph of this kind in my studio but got a bit waterlogged before I could pull it out to photograph.
I captured this dun on the same night as a spinner which is probably of the same species.
This little gal is of the usual size for Baetid mayflies, around size 20. She came with two tails, but it's kind of hard to transport size 20 mayflies without a little bit of damage.
10 Male Spinners
This is a tricky one to ID. The forewings seem to be on the low end of the "crossvein count" key characteristic. There are paired marginal intercalaries in the middle area of the fore wing (kind of visible in photos, verified 100 % under microscope), and the wing and its veins are pale. Keys would seem to point to Callibaetis pictus in this case, but several other characteristics including size don't fit (pictus is smaller), and this is a bit out of its range.
Some notes from identifying this specimen under the microscope:
1. The hind wing has three longitudinal veins, but the third is faint, short (about half the length of the wing), and close to the wing margin.
2. Then antenna is brown fading into white at the tip, and the base is ringed with white.
3. The joints of the tarsal segments on the middle and hind leg have fine black markings.
It was also collected in association with a female spinner.
1. The hind wing has three longitudinal veins, but the third is faint, short (about half the length of the wing), and close to the wing margin.
2. Then antenna is brown fading into white at the tip, and the base is ringed with white.
3. The joints of the tarsal segments on the middle and hind leg have fine black markings.
It was also collected in association with a female spinner.
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.
I love the shape of this guy's eyes.
I would not like to have to match this hatch. These are the smallest mayflies I have ever seen. I used to think Caenis was the smallest adult mayfly in the west but these guys are about 4mm long. The male eyes are two toned, brown above and olive below. The abdomen is dark brown interspersed with light brown. The abdomen is clear for the anterior 2/3rd and the remainder is white. The tails are twice as long as the insect. There is only one pair of wings.
15 Female Spinners
This female spinner was deceased when photographed, so the posture is unnatural, but it was a substantial hatch and clearly worth imitating (with wet flies to imitate the sunken ovipositing females) so I went ahead with the photos.
It was collected in association with a male spinner.
It was collected in association with a male spinner.
I captured and photographed this specimen as a dun before she molted into the spinner photographed here. Her wings got a bit torn up in the process.
This is one of the smallest mayflies I've ever collected, about 3mm long.
15 Nymphs
This specimen and many like it were found with other specimens I found to be duller-colored females of the same species. I wasn't aware of such a difference between male and female nymphs in Baetids, but all the morphological characteristics I checked in the key were the same, and the color patterns are, too -- just not the brightness.
A nymph of the same species as this one emerged into a dun in my studio so I got photos of both stages.
NOTE: I missed an important key characteristic the first time I tried to identify this one (robust setae on the abdominal sternites, which were harder to see than I expected but are clearly present), so I went on a bit of a wild goose chase and landed at a dead end. After spotting that characteristic, this one keys more straightforwardly to either Baetis tricaudatus or the Baetis piscatoris complex. It doesn't seem to be a perfect fit for either one in the key, but I'm going with tricaudatus based on range and abundance. It's not certain.
However, I'm leaving the flawed analysis below with this disclaimer, because some aspects of how I approached that dead end might be informative in the future.
----Incorrect analysis below----
After spending a lot of time with this one under my shiny new microscope, I'm still not quite sure what it is. I botched my attempt to expose the mouth parts that might make the ID more definitive. Based on the key in Webb et al 2018's "Baetis Larvae of North America," here's my reasoning at each key couplet.
Couplet 1. The pronotum lacks dark, submedian U-shaped markings. Also, if I were to follow through to couplet 2, there seem to be characteristics that rule out each of the options: the intercalaris complex is ruled out by the abdominal markings, and the caudal filaments have neither a dark median band (ruling out the flavistriga complex) nor uniform pale coloration (ruling out Baetis notos). This sends me with decent confidence to couplet 4.
Couplet 4. I cannot find robust setae in my microscope on the scapes, pedicels, paraprocts, or sterna. I also do not see a pair of dark, bilobed markings on the pronotum. Unless I overlooked these characteristics, proceed to couplet 9.
Couplet 9. Abdominal tergum 5 is a bit paler than adjacent terga, but "distinctly paler"? The figure for Baetis alius in the paper, as well as a very nice picture posted by Millcreek in the forum here, shows that Baetis alius would have darker tergites surrounding #5. So proceed to couplet 11.
Couplet 11. The length of the gills is obviously less than 2X their width. This leads to the Baetis vernus complex, which could include that species or Baetis brunneicolor. This key doesn't say how to tell those species apart.
Switching over to Burien et al 2018 as the source, the characteristics used to distinguish vernus from brunneicolor seem to rule out either one. Brunneicolor should have more uniformly brown abdominal tergites, whereas vernus should have a lack of visible tracheation in most of the gills.
The fore femur length is about 3.8x its width.
Also worth noting: In the genus ID, I thought I could see the villipore in my microscope, but I'm not sure. If I back out of Baetis altogether and assume there's no villipore, I end up at Fallceon, but this specimen doesn't seem to have the frontal keel on the head that's supposed to be present on Fallceon quilleri. So that seems like a dead end as well.
NOTE: I missed an important key characteristic the first time I tried to identify this one (robust setae on the abdominal sternites, which were harder to see than I expected but are clearly present), so I went on a bit of a wild goose chase and landed at a dead end. After spotting that characteristic, this one keys more straightforwardly to either Baetis tricaudatus or the Baetis piscatoris complex. It doesn't seem to be a perfect fit for either one in the key, but I'm going with tricaudatus based on range and abundance. It's not certain.
However, I'm leaving the flawed analysis below with this disclaimer, because some aspects of how I approached that dead end might be informative in the future.
----Incorrect analysis below----
After spending a lot of time with this one under my shiny new microscope, I'm still not quite sure what it is. I botched my attempt to expose the mouth parts that might make the ID more definitive. Based on the key in Webb et al 2018's "Baetis Larvae of North America," here's my reasoning at each key couplet.
Couplet 1. The pronotum lacks dark, submedian U-shaped markings. Also, if I were to follow through to couplet 2, there seem to be characteristics that rule out each of the options: the intercalaris complex is ruled out by the abdominal markings, and the caudal filaments have neither a dark median band (ruling out the flavistriga complex) nor uniform pale coloration (ruling out Baetis notos). This sends me with decent confidence to couplet 4.
Couplet 4. I cannot find robust setae in my microscope on the scapes, pedicels, paraprocts, or sterna. I also do not see a pair of dark, bilobed markings on the pronotum. Unless I overlooked these characteristics, proceed to couplet 9.
Couplet 9. Abdominal tergum 5 is a bit paler than adjacent terga, but "distinctly paler"? The figure for Baetis alius in the paper, as well as a very nice picture posted by Millcreek in the forum here, shows that Baetis alius would have darker tergites surrounding #5. So proceed to couplet 11.
Couplet 11. The length of the gills is obviously less than 2X their width. This leads to the Baetis vernus complex, which could include that species or Baetis brunneicolor. This key doesn't say how to tell those species apart.
Switching over to Burien et al 2018 as the source, the characteristics used to distinguish vernus from brunneicolor seem to rule out either one. Brunneicolor should have more uniformly brown abdominal tergites, whereas vernus should have a lack of visible tracheation in most of the gills.
The fore femur length is about 3.8x its width.
Also worth noting: In the genus ID, I thought I could see the villipore in my microscope, but I'm not sure. If I back out of Baetis altogether and assume there's no villipore, I end up at Fallceon, but this specimen doesn't seem to have the frontal keel on the head that's supposed to be present on Fallceon quilleri. So that seems like a dead end as well.
This specimen keys to the Baetis flavistriga complex, which could be either flavistriga or Baetis phoebus.
Under the microscope, this one clearly has hind wingpads.
Here I'm just copying and pasting, without cleaning up, my notes from spending a long time with this one under the microscope (and keying with Merritt & Cummins 5th Ed) only to end up confirming the most likely guess.
7. Baetis bicaudatus nymph
1. Hind wingpad present but small and hidden beneath forewing pad
2. Segment 2 of labial palp with well-developed medially projecting corner --> Baetis (couple 44). BUT no sign of scale-like setae on abdominal terga. Conflicts at this couplet.
3. Gills on segments I-VII
4. Tarsal claws with denticles, seemingly 2 rows but very hard to tell… and the key options with 2 rows don’t make sense
5. Assuming no villipore, we land confidently at couplet 48
6. Leads to Fallceon, except antennal scape doesn't have robust setae
7. Treated as Baetis, leads to brunneicolor, but McDunnough et al 1932 (Can Ent 64) suggests middle tail should be 5/6 as long as outer ones
8. Keys VERY confidently to couplet 36 in M&C (villipore)
9. If assuming villipore present:
1. 37 --> Scape of antennae has no distal lobe --> rules out Labiobaetis (100 % certain)
2. 38 --> Terminal filament much shorter than cerci --> not Barbaetis benfieldi (100 % certain)
3. 39 --> Terminal filament reduced (100 % certain)
4. 40 --> Tarsal claw denticle count couplet. If two rows of denticles: Either Iswaeon or Heterocloeon. Can't be Iswaeon because cerci lack dark median band. Can't be heterocloeon because it's not in the Platte drainage or in Texas. Thus, it must be one row of denticles. Moving on to 42.
5. 42 --> Hind wing pads present (100 % certain)
6. 44 --> Segment 2 of labial palpi with well-developed medially projecting corner (80 % certain), scale-like setae not evident on terga but maybe limitation of my scope --> Baetis (alternative would be Acentrella, but pronotum shape is all wrong for those, although not an official characteristic)
7. CONFIDENT in Baetis bicaudatus after distinctive leg markings (J-shaped light mark on first femur, L-shaped on second and third) matches original species description to a tee.
7. Baetis bicaudatus nymph
1. Hind wingpad present but small and hidden beneath forewing pad
2. Segment 2 of labial palp with well-developed medially projecting corner --> Baetis (couple 44). BUT no sign of scale-like setae on abdominal terga. Conflicts at this couplet.
3. Gills on segments I-VII
4. Tarsal claws with denticles, seemingly 2 rows but very hard to tell… and the key options with 2 rows don’t make sense
5. Assuming no villipore, we land confidently at couplet 48
6. Leads to Fallceon, except antennal scape doesn't have robust setae
7. Treated as Baetis, leads to brunneicolor, but McDunnough et al 1932 (Can Ent 64) suggests middle tail should be 5/6 as long as outer ones
8. Keys VERY confidently to couplet 36 in M&C (villipore)
9. If assuming villipore present:
1. 37 --> Scape of antennae has no distal lobe --> rules out Labiobaetis (100 % certain)
2. 38 --> Terminal filament much shorter than cerci --> not Barbaetis benfieldi (100 % certain)
3. 39 --> Terminal filament reduced (100 % certain)
4. 40 --> Tarsal claw denticle count couplet. If two rows of denticles: Either Iswaeon or Heterocloeon. Can't be Iswaeon because cerci lack dark median band. Can't be heterocloeon because it's not in the Platte drainage or in Texas. Thus, it must be one row of denticles. Moving on to 42.
5. 42 --> Hind wing pads present (100 % certain)
6. 44 --> Segment 2 of labial palpi with well-developed medially projecting corner (80 % certain), scale-like setae not evident on terga but maybe limitation of my scope --> Baetis (alternative would be Acentrella, but pronotum shape is all wrong for those, although not an official characteristic)
7. CONFIDENT in Baetis bicaudatus after distinctive leg markings (J-shaped light mark on first femur, L-shaped on second and third) matches original species description to a tee.
Another nymph probably of the same species as this one emerged and was photographed as a dun and partly-molted spinner.
These nymphs were highly abundant in my early April kick net samples from the Yakima Canyon, and one of them emerged into a dun, which I photographed immediately. Similar-looking nymphs but with distinctly brighter color patterns were also abundant. I just photographed one. After extensive views under the microscope, it's clear the bright ones are males and the dull ones are females of the same species.
The most likely guess at the species is Baetis tricaudatus, which may be a complex of related species that haven't all been sorted out yet. It isn't a perfect fit to every key characteristic (and I never seem to find a Baetis that matches the expected pronotum color patterns, but that seems to be the closest.
The microscope images here were taken with different specimens from the main photos (so I could dissect them while preserving that one intact), but clearly the same species.
The most likely guess at the species is Baetis tricaudatus, which may be a complex of related species that haven't all been sorted out yet. It isn't a perfect fit to every key characteristic (and I never seem to find a Baetis that matches the expected pronotum color patterns, but that seems to be the closest.
The microscope images here were taken with different specimens from the main photos (so I could dissect them while preserving that one intact), but clearly the same species.
I collected this one along with a male that was quite a bit smaller but equally ready to emerge in mid April.
I spent quite a while on the identifications, because they really don't look very much like the Baetis bicaudatus nymph I caught last year in Idaho. However, the presence of hind wing pads rules out Acentrella turbida and Iswaeon anoka, the lack of a fringe of long setae on the tibiae rules out Acentrella insignificans, range rules out Heterocloeon, and the thumb-like projection on the labial palp points to Baetis. Thus, Baetis bicaudatus is a fairly confident ID, and it's not too surprising that it looked different from my previous specimen because bicaudatus is thought to be a species complex with multiple types that haven't been fully sorted out yet.
The microscope pictures for this specimen aren't from the same exact nymph, but a mixture of a few others of the same kind that I didn't mind dissecting.
I spent quite a while on the identifications, because they really don't look very much like the Baetis bicaudatus nymph I caught last year in Idaho. However, the presence of hind wing pads rules out Acentrella turbida and Iswaeon anoka, the lack of a fringe of long setae on the tibiae rules out Acentrella insignificans, range rules out Heterocloeon, and the thumb-like projection on the labial palp points to Baetis. Thus, Baetis bicaudatus is a fairly confident ID, and it's not too surprising that it looked different from my previous specimen because bicaudatus is thought to be a species complex with multiple types that haven't been fully sorted out yet.
The microscope pictures for this specimen aren't from the same exact nymph, but a mixture of a few others of the same kind that I didn't mind dissecting.
This nymph was one of a horde I could see cruising the still shallows of a cold tailwater, mixed in with an intense emergence of duns. It's one of four specimens I photographed together from the same hatch, also including a male dun, a female dun, and a male spinner.
This nymph keys to either Callibaetis ferrugineous or Callibaetis pallidus. The lack of a darkened preapical band on the femora would suggest pallidus, but I can't definitively make out the "single seta" on the outer, ventral apex of any of the tarsi, the length of which is supposedly a more reliable characteristic to tell the species spart. I can maybe make something out on one of the legs at the highest magnification, and its dimensions would suggest ferrugineous.
This nymph keys to either Callibaetis ferrugineous or Callibaetis pallidus. The lack of a darkened preapical band on the femora would suggest pallidus, but I can't definitively make out the "single seta" on the outer, ventral apex of any of the tarsi, the length of which is supposedly a more reliable characteristic to tell the species spart. I can maybe make something out on one of the legs at the highest magnification, and its dimensions would suggest ferrugineous.
10 Streamside Pictures of Baetidae Mayflies:
Often mayflies can be found on houses near the river. This one molted from a dun into a spinner on the outside of our kitchen window.
Any lit dwelling near the river can attract a lot of mayflies at night. A good way to determine what's hatching is to visit a gas station (or anything else with bright lights) close to the river early in the morning.
Any lit dwelling near the river can attract a lot of mayflies at night. A good way to determine what's hatching is to visit a gas station (or anything else with bright lights) close to the river early in the morning.
In this picture: Mayfly Family Baetidae (Blue-Winged Olive).
Spent Acentrella turbida spinners on the water
In this picture: Mayfly Species Acentrella turbida (Tiny Blue-Winged Olive).
Callibaetis spinner on an alpine lake in Washington's Cascades, the one referred to by the alias of Upper Lake in my Golden Trout trip report.
In this picture: Mayfly Genus Callibaetis (Speckled Dun).
Baetis spinners trying to lay eggs on my waders
In this picture: Mayfly Genus Baetis (Blue-Winged Olive).
Female Baetid spinners were abundant subsurface looking for substrates to lay their eggs, and they found my waders. I'll update the ID for this picture after identifying the associated male spinner. I caught several fish on a small brown soft-hackle fished as a crude imitation of these spinners before the fish all started taking Tricorythodes spinners instead.
In this picture: Mayfly Family Baetidae (Blue-Winged Olive).
10 Underwater Pictures of Baetidae Mayflies:
Several Baetidae nymphs line up on a rock.
In this picture: Mayfly Family Baetidae (Blue-Winged Olive).
This is my favorite underwater picture so far. It shows a bunch of Simuliidae (black fly) larvae clinging to a rock and swinging in the fast current. There are also at least four visible mayfly nymphs, probably in the family Baetidae.
In this picture: Mayfly Family Baetidae (Blue-Winged Olive) and True Fly Family Simuliidae (Black Fly).
There are several mayfly and stonefly nymphs clinging to this log.
In this picture: Stonefly Family Taeniopterygidae (Willowfly) and Mayfly Family Baetidae (Blue-Winged Olive).
Several Baetid mayfly nymphs cling to this rock. There are also some clumps of small stones which hold strong caddisfly larvae.
In this picture: Insect Order Trichoptera (Caddisfly) and Mayfly Family Baetidae (Blue-Winged Olive).
In this picture: Mayfly Genus Epeorus (Little Maryatt) and Mayfly Family Baetidae (Blue-Winged Olive).
In this picture: Mayfly Genus Epeorus (Little Maryatt) and Mayfly Family Baetidae (Blue-Winged Olive).
In this picture: Insect Order Trichoptera (Caddisfly) and Mayfly Family Baetidae (Blue-Winged Olive).
Discussions of Baetidae
Possible ID
1 replies
Posted by Sreyadig on Apr 11, 2021 in the species Apobaetis futilis
Last reply on Apr 11, 2021 by Taxon
In searching for nymphs in my small stream in northern Maryland, 500 yards from the PA line, I came across a 2 tailed mayfly that was not a of the Epeorus genus.
It was in a fast riffle section along with Epeorus nymphs. This was about 3/8” in overall length including tails. Darker straw coloration with dark brownish black wing cases that were pronounced in color and shape. Biggest factor was the tails. Median caudal filament was truncated, very small compared to the outer pair. Not even sure if tail/ caudal filament should be used to describe. In my books the closest thing is the Pseudocloeon futile. Which is an old taxonomic name I’m finding out.
This find seems rare in my area and experience. Hopefully I can get a photo...
It was in a fast riffle section along with Epeorus nymphs. This was about 3/8” in overall length including tails. Darker straw coloration with dark brownish black wing cases that were pronounced in color and shape. Biggest factor was the tails. Median caudal filament was truncated, very small compared to the outer pair. Not even sure if tail/ caudal filament should be used to describe. In my books the closest thing is the Pseudocloeon futile. Which is an old taxonomic name I’m finding out.
This find seems rare in my area and experience. Hopefully I can get a photo...
Mayfiles other than Callibaetis
1 replies
Posted by Royal_Coach on Jan 15, 2018 in the genus Callibaetis
Last reply on Jan 15, 2018 by Millcreek
every book/article I read says Baetidae is the most imporant family and Callibaetis the most important genus of mayfly. Why? Does this just mean they are the most prolific? Am I not likely to encounter any other family/genus on a western river?
Big Green River, Wisconsin, late September
1 replies
Posted by Admiralb on Sep 28, 2013 in the species Baetis brunneicolor
Last reply on Sep 30, 2013 by Entoman
I hosted two visiting delegates to the T.U. National Convention in Madison, WI. on September 25, 2013, taking them to the Big Green River in Grant County near Fennimore. There was a high overcast in the morning, and these mayflies [which I merely called "BWO's" and imitated with #16 parachute dries - thin olive bodies, gray wing posts and dun parachute hackle] - were active. Both of my guests raised browns fishing a gray nymph behind a #16 parachute dry BWO. As long as my flies catch fish, I don't need to be a detailed entomologist. Nevertheless, I do sincerely appreciate the detailed scientific info, because it helps me focus my flytying and fly selection. Thank you.
Instant Baetid Nymph Patterns
36 replies
Posted by PaulRoberts on Feb 1, 2012
Last reply on Mar 7, 2013 by PaulRoberts
Often the first fishing for bug-eaters I do every year is the early Baetis activity. Then…the Baetid activity just continues through the year on virtually all the waters I fish. This is probably so for you all too.
I often fish a Baetid dry ahead of a Baetid nymph, since individual fish could be targeting either. I fish the #18 or #20 nymph on a short (~18-24”) length of 7x to the bend of the hook of a #16 Parachute dry. A tiny daub of tungsten putty helps the short fine dropper break the surface film, as it’s critical to have the dropper line as straight as possible as soon as possible so I can detect every take. I use this combination all year and it's even a smart prospecting rig on waters calm enough to see the small dry.
For my bread-n-butter recipes I can be a pretty lazy tier, so I want as close to an instant tie as I can get. The following are two ~4 minute recipes:
Parafilm Baetid:
This pattern uses a single section of mallard flank barbs (tinted ahead of time with a swipe of a permanent marker) for both the tail and the legs, using the tips for the tail and the butts for the legs. Parafilm (laboratory thermo-plastic film) is used for the body, and tinted with permanent markers. The Parafilm body makes the fly sink a little quicker than dubbed ones, esp with a heavy iron (like the 3906 in this pic).
It’s important to me to have the fly drift correctly in the water, not flip upside down. So it needs an ample tail to right the hook when it’s tethered. Also, with the Parafilm body it helps to adjust the legs with thread so they angle upwards, so they are above the central plane of the fly. I take the most time on this fly with the legs so they are equal on each side in number, length, thickness, and orientation. No need to be anatomically correct so two legs to a side is enough to suggest legs. I suspect the upside down or rolling flies affect my catch rate, as I’ve had repeated refusals to such flies and then made good by tying on a fresh one.
(Yeah, I know there are 4 legs on the left side -I snipped off #3 after I noticed.)
Baetid #2:
The second pattern is similar to a combination of the “WD40” and "Kimball's Emerger", except that it doesn’t bother with the wingcase. The wingcase is suggested with permanent markers: a spot of dark brown behind the head, and two black wing-buds. Again the tinted duck flank for tail and legs, then olive thread for the abdomen, a pale pinkish-golden dubbing for the thorax. Legs equal again, but not so critical that they ride well above the central (dorsal/ventral) plane, as the dubbing adds some buoyancy. The legs should not hang below the plane or the fly will likely ride upside down.
{EDIT}: Just noticed this fly has the wingcase, but I usually just omit it.
I tie a few others too, but these cover the dropper nymph deal pretty well for me.
What Baetid nymph patterns do you rely on?
I often fish a Baetid dry ahead of a Baetid nymph, since individual fish could be targeting either. I fish the #18 or #20 nymph on a short (~18-24”) length of 7x to the bend of the hook of a #16 Parachute dry. A tiny daub of tungsten putty helps the short fine dropper break the surface film, as it’s critical to have the dropper line as straight as possible as soon as possible so I can detect every take. I use this combination all year and it's even a smart prospecting rig on waters calm enough to see the small dry.
For my bread-n-butter recipes I can be a pretty lazy tier, so I want as close to an instant tie as I can get. The following are two ~4 minute recipes:
Parafilm Baetid:
This pattern uses a single section of mallard flank barbs (tinted ahead of time with a swipe of a permanent marker) for both the tail and the legs, using the tips for the tail and the butts for the legs. Parafilm (laboratory thermo-plastic film) is used for the body, and tinted with permanent markers. The Parafilm body makes the fly sink a little quicker than dubbed ones, esp with a heavy iron (like the 3906 in this pic).
It’s important to me to have the fly drift correctly in the water, not flip upside down. So it needs an ample tail to right the hook when it’s tethered. Also, with the Parafilm body it helps to adjust the legs with thread so they angle upwards, so they are above the central plane of the fly. I take the most time on this fly with the legs so they are equal on each side in number, length, thickness, and orientation. No need to be anatomically correct so two legs to a side is enough to suggest legs. I suspect the upside down or rolling flies affect my catch rate, as I’ve had repeated refusals to such flies and then made good by tying on a fresh one.
(Yeah, I know there are 4 legs on the left side -I snipped off #3 after I noticed.)
Baetid #2:
The second pattern is similar to a combination of the “WD40” and "Kimball's Emerger", except that it doesn’t bother with the wingcase. The wingcase is suggested with permanent markers: a spot of dark brown behind the head, and two black wing-buds. Again the tinted duck flank for tail and legs, then olive thread for the abdomen, a pale pinkish-golden dubbing for the thorax. Legs equal again, but not so critical that they ride well above the central (dorsal/ventral) plane, as the dubbing adds some buoyancy. The legs should not hang below the plane or the fly will likely ride upside down.
{EDIT}: Just noticed this fly has the wingcase, but I usually just omit it.
I tie a few others too, but these cover the dropper nymph deal pretty well for me.
What Baetid nymph patterns do you rely on?
North Country Spiders for Baetids
27 replies
Posted by Entoman on Oct 25, 2011
Last reply on Feb 16, 2012 by Softhackle
I wanted to share a couple of patterns that have proven very successful over the years (and the last several weeks in particular) when baetids are about. They hale from England where they have been popular for a very long time. Their construction is simple - silk thread, a wing covert or shoulder hackle, bee's wax, and maybe the merest smidgen of natural dubbing on a few of them. No plastic flash, no head cement, just natural materials delicately applied. There's something very elegant in their understated appearance, and boy do they work! Their thin bodies and sparseness ape the baetids perfectly and the hook set is enhanced as well.
Fished dead drift or under a controlled swing with the rod elevated, they can be deadly when the small stuff is awash in the drift. The two patterns below are the Waterhen Bloa and the Snipe & Purple both in the class of wet flies called North Country Spiders. I find them especially valuable for fishing during baetid spinner activity on freestone rivers in the moderate to slow current sections. They also work fishing "under" the hatch of duns. I never know which one they will prefer, nor have I found any increase in catch rate by doubling up on the one they do for that day, so I just tie 'em both on and leave it be.
Size 16 Waterhen Bloa
Size 18 Snipe & Purple
Fished dead drift or under a controlled swing with the rod elevated, they can be deadly when the small stuff is awash in the drift. The two patterns below are the Waterhen Bloa and the Snipe & Purple both in the class of wet flies called North Country Spiders. I find them especially valuable for fishing during baetid spinner activity on freestone rivers in the moderate to slow current sections. They also work fishing "under" the hatch of duns. I never know which one they will prefer, nor have I found any increase in catch rate by doubling up on the one they do for that day, so I just tie 'em both on and leave it be.
Size 16 Waterhen Bloa
Size 18 Snipe & Purple
Start a Discussion of Baetidae
References
- Arbona, Fred Jr. 1989. Mayflies, the Angler, and the Trout. Nick Lyons Books.
- Hafele, Rick and Hughes, Dave. 2004. Western Mayfly Hatches. Frank Amato Publications.
- Knopp, Malcolm and Robert Cormier. 1997. Mayflies: An Angler's Study of Trout Water Ephemeroptera . The Lyons Press.
Mayfly Family Baetidae (Blue-Winged Olives)
Taxonomy
Genus in Baetidae
AcentrellaTiny Blue-Winged Olives
7
45
AcerpennaTiny Blue-Winged Olives
5
32
AnafroptilumTiny Sulphur Duns
2
5
ApobaetisTiny Blue-Winged Olives
0
0
BaetisBlue-Winged Olives
36
248
CallibaetisSpeckled Duns
15
76
Camelobaetidius
0
0
CloeonTiny Sulphur Duns
0
0
DiphetorBlue-Winged Olives
1
6
FallceonBlue-Winged Olives
0
0
HeterocloeonTiny Blue-Winged Olives
0
0
IswaeonTiny Blue-Winged Olives
0
0
LabiobaetisTiny Blue-Winged Olives
0
0
Neocloeon
0
0
Paracloeodes
0
0
PlauditusTiny Blue-Winged Olives
0
0
ProcloeonTiny Sulphur Duns
2
9
PseudocloeonTiny Blue-Winged Olives
0
0
Waynokiops
0
0
Genus in Baetidae: Acentrella, Acerpenna, Anafroptilum, Apobaetis, Baetis, Callibaetis, Camelobaetidius, Cloeon, Diphetor, Fallceon, Heterocloeon, Iswaeon, Labiobaetis, Neocloeon, Paracloeodes, Plauditus, Procloeon, Pseudocloeon, Waynokiops
9 genera (Americabaetis, Baetodes, Baetopus, Barbaetis, Cloeodes, Kirmaushenkreena, Moribaetis, Pseudocentroptiloides, and Varipes) aren't included.