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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 12 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...111213...126

Isoperla (Stripetails and Yellow Stones) Stonefly Adult

View 10 PicturesSeveral stoneflies of this species were flying around a small stream last night. I tied on a brown drake imitation of about the right size/color to approximate these stones, and was rewarded with a hard-fighting 17-inch brown trout.

Collected July 7, 2006 from Cayuta Creek in New York
Added to Troutnut.com by Troutnut on July 8, 2006

Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly Nymph

View 6 PicturesThis pretty Ephemerella nymph has really weird markings. It has one band on the tibiae (

The tibia of this Isonychia bicolor mayfly spinner is highlighted in red.

Tibia: A middle segments in the leg of an insect, located between the femur and the tarsus.) and a thin but distinct dorsal (Dorsal: Top.) stripe faded in the center which looks very different from the stripes on Ephemerella needhami and Ephemerella aurivillii. It definitely has the fan tail characteristic of the Ephemerella genus.

Collected February 7, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Nymph

View 6 Pictures

Collected February 7, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Nigronia serricornis (Fishfly) Hellgrammite Larva

View 5 Pictures

Collected January 14, 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

Rheotanytarsus Midge Larva

View 6 PicturesThis peculiar midge lived in a case tightly fixed to a rock, with several others of its kind. The case seems to be made of tiny grains of sand. I'm not sure what the function is for the little lines sticking out the front, because they aren't legs.

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

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

Argia Damselfly Nymph

View 3 PicturesMy friend Willy captured this early instar (Instar: Many invertebrates molt through dozens of progressively larger and better-developed stages as they grow. Each of these stages is known as an instar. Hard-bodied nymphs typically molt through more instars than soft-bodied larvae.) damselfly nymph and brought it to me for identification. It is more robust and stocky at this early stage than the spindly appearance of the later instars (Instar: Many invertebrates molt through dozens of progressively larger and better-developed stages as they grow. Each of these stages is known as an instar. Hard-bodied nymphs typically molt through more instars than soft-bodied larvae.), and its appearance is less familiar.

Collected August 28, 2005 from Fall Creek in New York
Added to Troutnut.com by Troutnut on April 14, 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

Ephemera simulans (Brown Drake) Mayfly Nymph

View 6 Pictures

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

Specimen Page:1...111213...126

Jargon Defined:

Dorsal: Top.

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.

Instar: Many invertebrates molt through dozens of progressively larger and better-developed stages as they grow. Each of these stages is known as an instar. Hard-bodied nymphs typically molt through more instars than soft-bodied larvae.

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.

The tibia of this Isonychia bicolor mayfly spinner is highlighted in red.

Tibiae: A middle segments in the leg of an insect, located between the femur and the tarsus.

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.