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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 15 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...141516...126

Female Heptageniidae (March Browns, Cahills, Quill Gordons) Mayfly Dun

View 10 PicturesThis specimen is really strange, very different in form from any other mayfly I've seen. Unfortunately it was found alone crippled in an eddy and in pretty bad shape, and I couldn't find any others like it.

Collected June 28, 2005 from the Long Lake Branch of the White River in Wisconsin
Added to Troutnut.com by Troutnut on May 26, 2006

Maccaffertium ithaca (Light Cahill) Mayfly Nymph

View 9 PicturesThis specimen seems to be of the same species as a dun I photographed which emerged from another nymph in the same sample.

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

Amphipoda (Scuds) Scud Adult

View 4 Pictures

Collected January 31, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Agnetina capitata (Golden Stone) Stonefly Adult

View 8 PicturesThis stonefly emerged in my aquarium, and unfortunately I severely damaged its wings just trying to catch it. It's still an interesting specimen, especially since I was able to also photograph 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.) it emerged from. I was surprised by just how light it was shortly after emerging. I photographed it a couple days later when it had darkened considerably; it was a pale, almost pastel yellow at first.

Collected May 1, 2007 from Aquarium in New York
Added to Troutnut.com by Troutnut on May 3, 2007

Tallaperla (Roachflies) Stonefly Nymph

View 7 Pictures

Collected April 1, 2007 from Mystery Creek #62 in New York
Added to Troutnut.com by Troutnut on April 3, 2007

Limnephilidae (Northern Caddisflies) Caddisfly Larva

View 5 Pictures

Collected March 1, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

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

Female Tricorythodes (Tricos) Mayfly Spinner

View 4 PicturesThis recently deceased Trico was smaller and darker than the others I photographed from the same morning.

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

Female Baetidae (Blue-Winged Olives) Mayfly Dun

View 5 PicturesI captured this dun on the same night as a spinner which is probably of the same species.

Collected August 9, 2006 from the West Branch of Owego Creek in New York
Added to Troutnut.com by Troutnut on August 11, 2006

Paragnetina immarginata (Beautiful Stonefly) Stonefly Adult

View 9 Pictures

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

Specimen Page:1...141516...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.

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.