Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin

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.

Stream photos

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Limnephilidae (Giant Sedges) Caddisfly Larva Limnephilidae (Giant Sedges) Caddisfly Larva

Dorsal view of a Limnephilidae (Giant Sedges) Caddisfly Larva from the Yakima River in Washington

This specimen resembled several others of around the same size and perhaps the same species, which were pretty common in my February sample from the upper Yakima. Unfortunately, I misplaced the specimen before I could get it under a microscope for a definitive ID.

10 Recently Added Photos

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.

Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

midges two by two?

This topic is about the True Fly Family Chironomidae

Midges are the most important aquatic insects in some places, especially fertile spring creeks where they are extremely abundant and the current is so slow that it's efficient for trout to surface feed on very tiny insects.

Some midges are large, up to hook size 14, but the majority are size 22 or smaller. The number of genera and species is hopelessly huge for angler entomologists to ever learn, and the identifing characteristics often require slide-mounting tiny parts under high-powered microscopes. Even the most Latin-minded fisherman must slip back to the basics--size and color--to describe his local midge hatches.

Example specimens

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Chironomidae (Midge) True Fly Larva

Dorsal view of a Chironomidae (Midge) True Fly Larva from the South Fork Snoqualmie River in Washington

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Chironomidae (Midge) True Fly Larva

Lateral view of a Chironomidae (Midge) True Fly Larva from the South Fork Snoqualmie River in Washington

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Chironomidae (Midge) True Fly Adult

Lateral view of a Chironomidae (Midge) True Fly Adult from the South Fork Snoqualmie River in Washington

This extremely tiny fly was puzzling to identify. I collected it from a sparse mating swarm just above the surface of the river. It just doesn't have the "look" I'm used to seeing in Chironomids, but the key characteristics in Merritt, Cummins, & Berg point that way. -Maxillary palp apparently with 4 segments, antenna with 6 -I can't see any ocelli and wing venation doesn't seem to match Axymyiidae -Costa definitely ends at or near apex of the wing (pictured) -Obvious characteristics and wing venation rule out a few other things -Simuliidae seems like a possibility due to the broad wings, but bugguide says they're supposed to have more antennal segments (eleven, though a different source says some have ten, at least in the Southern Hemisphere). -Postnotum with median longitudinal groove (pictured) rules out Ceratopogonidae So my guess is some kind of chironomid from a genus that doesn't have the classic midge look. There are some like that.

CaseyP

Arlington, VA/ Mercersburg, PA

Posts: 653

CaseyP on May 24, 2007May 24th, 2007, 3:13 am EDT

in the air over the stream last night was a cloud of "midges", all floating in pairs. the hundreds of pairs looked like little colons (:), little black dots keeping a constant distance. you had to see it to believe it. mating dances? has anyone else seen this?

river: Little Juniata, PA
water temp: 62 degrees
air temp: high 70s
time: twilight

"You can observe a lot by watching." Yogi Berra

Troutnut

Administrator
Bellevue, WA

Posts: 2758

Troutnut on May 24, 2007May 24th, 2007, 3:39 am EDT

Can't say that I have. Maybe they were all joined mating?

Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist

CaseyP

Arlington, VA/ Mercersburg, PA

Posts: 653

CaseyP on May 24, 2007May 24th, 2007, 5:02 am EDT

the pairs were closer to each other than to other pairs, and the pairs were about equidistant from other pairs as they moved in the air. it looked like space was important, like birds on a wire; one of nature's really amazing regular patterns, i guess.

"You can observe a lot by watching." Yogi Berra

Troutnut

Administrator
Bellevue, WA

Posts: 2758

Troutnut on May 24, 2007May 24th, 2007, 5:49 am EDT

Oh, so they weren't touching. I guess that rules out mating. Still probably some behavior related to that. It sounds really interesting.

Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist

CaseyP

Arlington, VA/ Mercersburg, PA

Posts: 653

CaseyP on May 25, 2007May 25th, 2007, 3:24 pm EDT

can we post video on this board? my camera can take short sequences of up to a minute, so next time i see this midge dancing class i'll think to record it.

"You can observe a lot by watching." Yogi Berra

Martinlf

Moderator
Palmyra PA

Posts: 3047

Martinlf on May 26, 2007May 26th, 2007, 1:25 pm EDT

Casey, wish I'd known you were up at the J. I just returned from a two night trip (24th and 25th), and Jason joined me last night for a dense sulphur spinner fall. I'll let him tell you about it. How was your fishing?

"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell