**Mayfly Species Diphetor hageni (Iron Blue Quill)**

Mayflies

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Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Baetidae (Blue-Winged Olives)

» Genus Diphetor (Blue-Winged Olives)

» Species hageni (Iron Blue Quill)

Common Names

Match	Common Name
	Iron Blue Quill
	Blue-Winged Olive
	Little Iron Blue Quill
	Little Western Iron-Blue Quill
	Dark Brown Spinner
	Dark Brown Dun

This is one of the most important species of the Baetidae family. It is distributed across the country, but most of its fame comes from excellent hatches in the West where it is probably the most populous member of the Baetidae family.

Diphetor hageni has two former names used in angling literature, Baetis parvus in the West and Baetis divinctus in the East.

Where & When

Regions: East, Midwest, West

Time Of Year (?): April and May, then another brood in September and October; sometimes another intermediate brood

Preferred Waters: Fertile streams

Hatching Behavior

The nymphs and duns are both important during this hatch.

Spinner Behavior

Fred Arbona in Mayflies, the Angler, and the Trout describes peculiar spinner behavior in this species:

Spinners gather in the mornings or evenings, and their tight swarms can be observed over the banks of the stream. After mating, the spinners suddenly vanish and reappear spent (Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.) on the water.

Nymph Biology

These nymphs are very versatile: cold or warm water, slow or fast water, spring creeks and freestone streams.

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Jargon Defined:

Brood: When a species produces more than one generation per year, each one is called a brood.

Duns: 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.

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).

Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.

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.

Useful References:

Arbona, Fred Jr. 1989. Mayflies, the Angler, and the Trout. Nick Lyons Books.

Caucci, Al and Nastasi, Bob. 2004. Hatches II. The Lyons Press.

Knopp, Malcolm and Robert Cormier. 1997. Mayflies: An Angler's Study of Trout Water Ephemeroptera . The Lyons Press.