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Arthropod Class Insecta (Insects)

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

Order in Insecta
ColeopteraBeetles	7	24
DipteraTrue Flies	56	284
EphemeropteraMayflies	821	4053
HemipteraTrue Bugs	9	48
HymenopteraAnts, Bees, and Wasps	10	40
LepidopteraMoths	3	16
MegalopteraHellgrammites, Dobsonflies, and Alderflies	13	90
Odonata-AnisopteraDragonflies	12	31
Odonata-ZygopteraDamselflies	8	30
OrthopteraGrasshoppers and Crickets	1	7
PlecopteraStoneflies	147	781
Psocodea	1	4
TrichopteraCaddisflies	129	820

1 order isn't included.

Common Name

Match	Common Name
	Insects

Pictures Below ↓

Nearly a million species of insects have been described by entomologists. I have left several of them off of this site, just to save time, but I've tried to include all the main aquatic insects trout eat in North America.

This site focuses on aquatic insects, of which the most important are mayflies (Ephemeroptera) and caddisflies (Trichoptera). Stoneflies (Plecoptera) come in third, a position arguably challenged by the many two-winged true flies of the Diptera order, which includes midges and craneflies. I've also included some terrestrial (Terrestrial: Insects which live on land and are fed on by trout only when they incidentally fall into the water are known as "terrestrials" to fly anglers, and they're very important in late summer.) insects which I've found on or near trout streams. Terrestrials (Terrestrial: Insects which live on land and are fed on by trout only when they incidentally fall into the water are known as "terrestrials" to fly anglers, and they're very important in late summer.) like ants, beetles, and grasshoppers are an important food source for trout in many places, especially during the summer months.

Aquatic insects do not live their entire lives in the water. Instead, they grow for a year (give or take quite a bit) as nymphs or larvae underwater, and then they emerge into air-breathing winged insects for a short while to mate and die. There are many variations on this theme.

The most important aquatic insects for fly fishermen are mayflies, stoneflies, caddisflies, and midges. Mayflies and caddisflies are the most discussed by angler-entomologists, because it's so useful to closely identify them. The behavior of their species guides the behavior of feeding trout, and an angler who understands the lifecycle of a particular species has the upper hand when it's hatching. This is not so important for stoneflies and midges, because their hatching behavior is less variable.

Pictures of 1229 Insect Specimens:

Specimen Page:12 3 4...124

Baetisca obesa (Armored Mayfly) Mayfly Nymph

View 12 Pictures

Collected May 6, 2007 from the Neversink River (above reservoir) in New York
Added to Troutnut.com by Troutnut on May 10, 2007

Neophylax (Autumn Mottled Sedges) Caddisfly Adult

View 20 PicturesThis large caddisfly looks really neat close-up.

Collected September 19, 2006 from Mystery Creek #43 in New York
Added to Troutnut.com by Troutnut on October 4, 2006

Male Baetis (Blue-Winged Olives) Mayfly Dun

View 14 PicturesThis 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.

Collected September 19, 2006 from Mystery Creek #43 in New York
Added to Troutnut.com by Troutnut on October 4, 2006

Specimen Page:12 3 4...124

114 Underwater Pictures of Insects:

Underwater Photo Page:12 3 4...13

View Full Size and Comment (2.5X larger)

Hundreds of cased caddisfly larvae live on this log in a small brook trout stream.

In this picture: Insect Order Trichoptera (Caddisflies).

StateWisconsin

LocationEighteenmile Creek

Date TakenApr 14, 2004

Date AddedJan 25, 2006

AuthorTroutnut

CameraOlympus C740UZ

Shown Full Size

A Brachycentrus "Apple Caddis" pupa scoots around in the surface film. Apparently it had some difficulty emerging, so I was able to slip my camera underneath it and take a picture from below.

In this picture: Caddisfly Species Brachycentrus appalachia (Apple Caddis).

StateNew York

LocationEast Branch of the Delaware River

Date TakenApr 19, 2006

Date AddedApr 22, 2006

AuthorTroutnut

CameraPENTAX Optio WPi

Shown Full Size

In this picture: Insect Order Trichoptera (Caddisflies) and Animal Class Gastropoda (Snails).

StateWisconsin

LocationNamekagon River

Date TakenMar 24, 2004

Date AddedJan 25, 2006

AuthorTroutnut

CameraOlympus C740UZ

Underwater Photo Page:12 3 4...13

Recent Discussions of Insecta

Trico nymphs and emergers 2 Replies »

Posted by Steamntrout on Sep 10, 2021 in the genus Tricorythodes

Last reply on Sep 11, 2021 by Martinlf

Recently I decided to tie up some trico soft hackle flies, and wanted to do as I have been for a while tie up Nymphs, emergers, and drys to have a better arsenal in my offerings.

I find very little on trico nymphs, and less for emergers.

Would really like to see some photos of the actual bug with actual measurements not hook sizes.

Reply Possible ID 2 Replies »

Posted by Sreyadig on Apr 11, 2021 in the species Apobaetis futilis

Last reply on Apr 19, 2021 by Crepuscular

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...

Reply Hexagenia orlando 5 Replies »

Posted by Curtis on Feb 29, 2008 in the genus Hexagenia

Last reply on Nov 20, 2020 by SALTYQUILL

Does anyone have any hatch dates for hexagenia orlando in the Central Florida area? Several lakes near me have populations and I am gathering data. I have photos and one hatch record.

Reply Yea...

Posted by Imaxfli on Oct 23, 2020 in the species Ephoron leukon

Me too looking for photos or better yet, video of matching. These things seem to pop outa the water like no other ......

Reply Trico emergers 6 Replies »

Posted by Bwoklink on Jul 14, 2018 in the genus Tricorythodes

Last reply on Sep 11, 2020 by Martinlf

Anyone have experience fishing Trico emergers patterns? I’ve had experience fishing the winged and spinner stage, but haven’t heard of anyone fishing emergers during the early morning female hatch. Anyone used emerger patterns and if so would you might sharing which ones you have found effective?

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Jargon Defined:

Dun: Mayflies have two adult stages. They first emerge from the water as duns (scientifically known as the subimago stage). They then molt into the spinner (imago) stage, in which they mate and die. Sometimes the word "dun" is confusingly used to refer to a brownish gray color in fly tying materials.

Larvae: Many classes of aquatic insects, such as caddisflies, midges, craneflies, dobsonflies, alderflies, and many more, are known as "larvae" rather than "nymphs" in their juvenile stages. They have mostly soft bodies rather than hard exoskeletons. These insects also advance through a "pupa" stage before reaching adulthood.

Nymphs: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).

Pupa: Any insect which spends most of its juvenile lifetime as a larva first becomes a pupa for a time before emerging as a fully grown adult. Depending on the species, the pupal form can be very important for fly fishermen to imitate.

Spinner: There are two winged stages of adult mayflies. They emerge from the water as duns, molt on land (usually) into their fully mature stage, spinners. As spinners, they mate, lay eggs, and die.

Terrestrial: Insects which live on land and are fed on by trout only when they incidentally fall into the water are known as "terrestrials" to fly anglers, and they're very important in late summer.