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Mayfly Genus Leptophlebia (Black Quills and Blue Quills)

Taxonomic Navigation -?-
» Genus Leptophlebia (Black Quills and Blue Quills)
Species in LeptophlebiaNumber of SpecimensNumber of Pictures
Leptophlebia cupidaBlack Quill1773
Leptophlebia johnsoniWhirling Dun00
Leptophlebia nebulosaBlack Quill00

4 species aren't included.
Common Names
Pictures Below
Leptophlebia mayflies do not generate superhatches, but their medium-large size and other properties make them a relevant part of the early season.

The information below was mostly discovered in Leptophlebia cupida, the most important species, but it is not known to differ in the others.
  

Where & When


Caucci and Nastasi in Hatches II tell an interesting story of their unsuccessful search for fishable populations of Leptophlebia nymphs. I have had better luck. They searched during the time when these nymphs are supposedly concentrated in schools in preparation for emergence; this may be exactly why they did not catch any. If the nymphs abandoned most of their habitat to gather in schools, they would be hard to find without some luck to stumble upon one of the schools. I have sampled good populations of Leptophlebia cupida from prime trout water during January and February, when they were more spread out.

Hatching Behavior


Time Of Day (?): Sporadic from midday through evening, usually peaking near midday

Water Temperature: 55F and up
The duns usually emerge laboriously at the surface. Fred Arbona notes in Mayflies, the Angler, and the Trout that they swim to and from the surface for an hour before they emerge, a habit usually found in the Ephemerellidae family.

Some authors report that they occasionally crawl out onto shore to emerge.

Spinner Behavior


Time Of Day: Afternoon and evening

Habitat: Medium to fast water
Most sources say the spinners lay their eggs over fast water, but I have watched them over smooth-water runs of medium current speed, too. The females rise and fall over the water to oviposit, dropping some eggs as they contact the surface at the bottom of each dive. As they fall they lock their wings in a V-shaped position and look like little airplanes dive-bombing the surface.

When they fall spent (Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.) or get stuck on the surface during egg-laying, they are taken eagerly by trout. To my knowledge these spinner falls are never very intense, but they can get the trout rising. I have seen it on a little farmland brookie stream in Wisconsin.

Nymph Biology


Current Speed: Slow

Substrate: Silt, detritus (Detritus: Small, loose pieces of decaying organic matter underwater.), leaf drift (Leaf drift: The mass of dead leaves gathered on the bottom of the stream, sometimes stacked thick in still places like back eddies. Many aquatic invertebrates use the leaf drift for shelter and food. Most insects shred the leaves to digest the bacteria and plankton living on them, rather than digesting the leaves themselves.)

Although Leptophlebia cupida nymphs are universally described as slow-water dwellers, I have also found good concentrations in strong riffles. They probably reside in slow microhabitats near the bank and in pockets in these fast stretches of the river.

These nymphs are known for gathering in schools like little minnows and migrating for distances up to a mile through the slow shallows of a river before emerging. The word "migration" is overused in angling entomology books to describe the pre-emergence activities of many species, but this is one of the only mayflies for which the word is no exaggeration.

Some authors say that Leptophlebia nymphs are poor swimmers, but I have found the opposite. They are a notch slower than the true swimmer families, but they swim much faster and more gracefully than other crawlers or clingers like Ephemerellidae and Heptageniidae. If they were as slow as some suggest, their lengthy migrations would be difficult to believe.

Because the nymphs are especially tolerant of warm, slow-flowing water, they make excellent aquarium mayflies. They are good species to take to the science classroom, where they can survive in a goldfish bowl with a few leaves in it and are likely to emerge before the end of the spring term.

In the wild, the nymphs are mostly nocturnal.

Pictures of 20 Mayfly Specimens in the Genus Leptophlebia:

Specimen Page:123
Female Leptophlebia (Black Quills and Blue Quills) Mayfly DunFemale Leptophlebia (Black Quills and Blue Quills) Mayfly Dun View 7 PicturesI collected this mayfly after user Al514 tipped me off to the presence of some Leptophlebia mayflies I didn't seem to have yet with his ID request of a male dun. This seems to be of the same species. I also collected a female spinner. Based on that spinner, I can tell that this is either Leptophlebia cupida or Leptophlebia nebulosa, but I can't tell which.

Unfortunately none of the specimens I collected made it through the hot, sunny day very well. So the pictures aren't great, but they're better than nothing.
Collected May 9, 2007 from Factory Brook in New York
Added to Troutnut.com by Troutnut on May 18, 2007
Specimen Page:123

Recent Discussions of Leptophlebia

Steamntrout
Posted by Steamntrout on Jun 14, 2017 in the species Leptophlebia nebulosa
Looking at Purdue's May Fly Central it shows nebulosa being found in Canada's Far North, North East and North West as well as USA's North East, South East & Far West.
ReplySoutheast Mayflies 24 Replies »
Posted by DarkDun on Nov 20, 2006 in the species Leptophlebia cupida
Last reply on Mar 4, 2007 by Taxon
This is one of the species that seem to be prevalent in our area of southwest NC. It emerges in March as I recall and again in October on certain streams. I would like to confirm that this next season.
Reply

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