Looking to do something outdoors and asocial during July 4th of the year of Covid-19, I took my wife to a small stream full of feisty westslope cutthroat trout. Of course, being July 4th, there were a few people around the easy-to-access spots (i.e. places to drive and set up a cushy camp ten feet from the truck), but it was easy to walk past them and have a beautiful little stream to ourselves. I'm both baffled and grateful that so few people see the value in chasing little trout in pretty little streams.
Male Rhithrogena hageni (Western Black Quill) Mayfly SpinnerView 15 PicturesI collected this spinner from the trail (old logging road) above a whitewater canyon on a small stream in the Cascades. I'm fairly positive on the ID: in Traver 1935 it keys out to Rhithrogena doddsi, which is now a synonym (Synonym: A former name of a taxon, usually a species. Entomologists frequently discover that two insects originally described as different species are one in the same, and they drop one of the names. The dropped name is said to be a synonym of the remaining name. These changes take a while to trickle into the common knowledge of anglers; for example, Baetis vagans is now a synonym of Baetis tricaudatus.) of Rhithrogena hageni. The penes (Penes: The paired genital structures of most male insects, which vary widely in form and are one of the main characteristics used for species identification.) differ slightly from the drawing in that book, but they're a very close match to drawing from the original hageni description in Eaton 1885.
Lastly, I have included here a couple pictures of the genitalia of a different specimen collected on the same evening, from the same river, and I think even the same swarm (although I don't recall that 100 %). They're angled a bit differently, and I couldn't locate the mid-ventral (Ventral: Toward or on the bottom.) spines, but I'm guessing I'm just seeing intra-species variation.
Tergite: The top (dorsal) part of a single segment on an insect's abdomen when it consists of a single chitinous plate (sclerite), or an individual sclerite if the segment has more than one.) coloration, dark streaks on the femora (
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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.
Femora: The main segment of an insect's leg close to the body, in between the tibia and the trochanter.
Larvae: 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.
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).
Penes: The paired genital structures of most male insects, which vary widely in form and are one of the main characteristics used for species identification.
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.
Synonym: A former name of a taxon, usually a species. Entomologists frequently discover that two insects originally described as different species are one in the same, and they drop one of the names. The dropped name is said to be a synonym of the remaining name. These changes take a while to trickle into the common knowledge of anglers; for example, Baetis vagans is now a synonym of Baetis tricaudatus.