Ephemerella invaria (Sulphur Dun) Mayfly Nymph Pictures

Mayflies

Caddisflies

Stoneflies

Classification

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs)

» Genus Ephemerella (Hendricksons, Sulphurs, PMDs)

» Species invaria (Sulphur Dun)

I looked at this small Ephemerella nymph very carefully under a microscope. It as no abdominal tubercles (

A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.

Tubercle: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.) and 1-banded 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.). I think just a very 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.) invaria nymph.

This mayfly was collected from unknown on February 7th, 2004 and added to Troutnut.com on January 25th, 2006.

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Ephemerella invaria (Sulphur Dun) Mayfly Nymph from unknown in Wisconsin

AuthorTroutnut

CameraOlympus C740UZ

Shown Full Size

AuthorTroutnut

CameraOlympus C740UZ

Shown Full Size

AuthorTroutnut

CameraOlympus C740UZ

Shown Full Size

AuthorTroutnut

CameraOlympus C740UZ

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Jargon Defined:

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).

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.

A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.

Tubercles: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.