Troutnut.com Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

Caddisfly Genus Onocosmoecus (Great Late-Summer Sedges)

Taxonomic Navigation -?-
» Genus Onocosmoecus (Great Late-Summer Sedges)
Species in OnocosmoecusNumber of SpecimensNumber of Pictures
Onocosmoecus unicolorGreat Late-Summer Sedge320

1 species isn't included.
Common Names
MatchCommon Name
***Great Late-Summer Sedges
*Northern Caddisflies


Pictures Below ↓

This is page 2 of specimens of Onocosmoecus. Visit the main Onocosmoecus page for:

  • The behavior and habitat of Onocosmoecus.

Pictures of 5 Caddisfly Specimens in the Genus Onocosmoecus:

Specimen Page:12
Male Onocosmoecus unicolor (Great Late-Summer Sedge) Caddisfly AdultMale Onocosmoecus unicolor (Great Late-Summer Sedge) Caddisfly Adult View 15 PicturesI first just assumed this was Dicosmoecus based on anglers' conventional wisdom since it's a large orange "October caddis," but Creno set me straight. I should have keyed it out. After another look under the microscope, it lacks an anepisternal wart on the mesopleuron (Mesopleuron: The side of the insect mesothorax, and the part to which the fore wings are attached in mayflies.), which rules out Dicosmoecus. The midtibiae have 2 apical (Apical: Close to the apex; tip or end.) spurs and 1 pre-apical (Apical: Close to the apex; tip or end.) spur, and from there the color pattern of the wing points to Onocosmoecus. The location then narrows the species to unicolor.
Collected September 17, 2020 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on September 19, 2020
Onocosmoecus unicolor (Great Late-Summer Sedge) Caddisfly AdultOnocosmoecus unicolor (Great Late-Summer Sedge) Caddisfly Adult View 11 PicturesOne key characteristic not clearly photographed, but clear in under the microscope: this specimen's midtibiae have 2 apical (Apical: Close to the apex; tip or end.) spurs and 1 preapical spur.
Collected August 4, 2020 from Trealtor Creek in Idaho
Added to Troutnut.com by Troutnut on August 20, 2020
Specimen Page:12
Top 10 Fly Hatches
BaetisBaetidaeEphemerellidaeHexagenia limbataChironomidaeHeptageniidaeEphemerella subvariaEphemerellaIsonychiaHydropsychidae
Top Gift Shop Designs
I outfish my daddy!Electric blue Hendrickson dun.I love buggers. Big, green, wooly ones.I outfish my husband!Be the trout.
Eat mayflies.
Top Insect Specimens
Baetisca obesa Mayfly NymphNeophylax Caddisfly AdultCorydalus Hellgrammite LarvaRhyacophila fuscula Caddisfly LarvaPteronarcys biloba Stonefly Nymph
Miscellaneous Sites
Dalton Highway (Haul Road) Corridor Map