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Animal Phylum Arthropoda (Arthropods)

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

Class in Arthropoda
ArachnidaMites and Spiders	0	1
CollembolaSpringtails	0	0
Crustacea-MalacostracaCrayfish, Scuds, and Sowbugs	0	10
Crustacea-Maxillopoda	0	0
InsectaInsects	0	114

Common Name

Match	Common Name
	Arthropods

Pictures Below ↓

This is page 9 of specimens of Arthropoda. Visit the main Arthropoda page for:

The behavior and habitat of Arthropoda.
122 underwater pictures of Arthropoda.

Pictures of 1244 Arthropod Specimens:

Specimen Page:1...8910...126

Female Baetisca laurentina (Armored Mayfly) Mayfly Spinner

View 9 Pictures

Collected June 1, 2005 from the Bois Brule River in Wisconsin
Added to Troutnut.com by Troutnut on May 24, 2006

Maccaffertium ithaca (Light Cahill) Mayfly Dun

View 9 PicturesThis dun emerged from a nymph in one of the bowls on my table while I was sorting. I photographed it with the nymphal shuck (

View Full Size

Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.

Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.), and it seems to be of the same species as a nymph I photographed from the same sample.

Collected May 29, 2007 from Paradise Creek in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007

Epeorus (Little Maryatts) Mayfly Nymph

View 9 Pictures

Collected May 6, 2007 from Mongaup Creek in New York
Added to Troutnut.com by Troutnut on May 18, 2007

Male Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Spinner

View 15 PicturesI wasn't actually fishing the river where I caught this one. I was just scouting, didn't like the look of the water, and as I was walking back to the car this little dun landed on my vest. Why can't they all be so easy to collect?

Collected September 8, 2006 from the East Branch of the Delaware River in New York
Added to Troutnut.com by Troutnut on October 4, 2006

Male Stenacron interpunctatum (Light Cahill) Mayfly Spinner

View 8 Pictures

Collected June 10, 2005 from the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on May 26, 2006

Brachycentrus (Grannoms) Caddisfly Pupa

View 10 PicturesThe green blob contained in this case is a pupa in the early stages of transformation from larva to the final stage we generally picture and imitate. This specimen and several like it were fixed to a rock I picked up, and each one had the front of its case sealed off, protecting the helpless pupa from predation. It's neat to see the insect part-way through such a radical transformation.

It was very hard to extract this thing from its case, so there's a bit of extra goo near the head from where I accidentally punctured it.

Collected April 14, 2007 from Cayuta Creek in New York
Added to Troutnut.com by Troutnut on April 22, 2007

Hydropsyche (Spotted Sedges) Caddisfly Pupa

View 8 PicturesSeveral users have interesting comments in the discussion of this specimen, but this observation by Creno is especially good:

Also, this is what I would call an "immature" pupa. The wingpads of caddis pupae darken to nearly black as the enclosed adults near emerging. The darkening is the developing adult wing inside the pupal wing pad (

The wing pads on this final instar Baetidae mayfly nymph are extremely dark.
Wing pad: A protrusion from the thorax of an insect nymph which holds the developing wings. Black wing pads usually indicate that the nymph is nearly ready to emerge into an adult.). The ultimate coloration of the adult wing is not very apparent in most pupal wing pads (

The wing pads on this final instar Baetidae mayfly nymph are extremely dark.
Wing pad: A protrusion from the thorax of an insect nymph which holds the developing wings. Black wing pads usually indicate that the nymph is nearly ready to emerge into an adult.) as the majority of the adult wing coloration comes from the color/position of the adult wing hairs and setae (Seta: Little hairs on insects.). But dark pupal wingpads are a good indication that the emergence will occur very soon, likely that day or so, and that the adult parts are sufficiently developed within the pupae to make a species determination from the specimen, particularly if it is a male.

Collected May 13, 2007 from the Delaware River in New York
Added to Troutnut.com by Troutnut on May 18, 2007

Male Rhithrogena morrisoni (Western March Brown) Mayfly Spinner

View 9 Pictures

Collected June 22, 2017 from the South Fork Snoqualmie River in Washington
Added to Troutnut.com by Troutnut on June 23, 2017

Male Epeorus pleuralis (Quill Gordon) Mayfly Spinner

View 10 PicturesA few days earlier I photographed this same specimen as a dun. The changes between dun and spinner seem particularly dramatic in this species.

Collected April 30, 2007 from Dresserville Creek in New York
Added to Troutnut.com by Troutnut on May 3, 2007

Female Hexagenia limbata (Hex) Mayfly Dun

View 8 Pictures

Collected June 13, 2005 from the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on May 26, 2006

Specimen Page:1...8910...126

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.

Emergence: The transformation of a nymph or pupa into the adult winged stage of an insect. The term may refer to the emergence of an individual, or the daily or yearly event in which all individuals of a species emerge.

Larva: 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.

Nymph: 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.

Setae: Little hairs on insects.

View Full Size

Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.

Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.

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.

The wing pads on this final instar Baetidae mayfly nymph are extremely dark.

Wing pad: A protrusion from the thorax of an insect nymph which holds the developing wings. Black wing pads usually indicate that the nymph is nearly ready to emerge into an adult.