Aquatic Insect #1 ID?

Discussion in 'Fly Fishing Entomology' started by Taxon, May 3, 2012.

  1. Taxon

    Taxon Moderator Staff Member

    [​IMG]

    This aquatic insect is common in WA. Can you identify it by any of the following?

    • Order common name: (Caddisfly, Mayfly, Stonefly, True Fly, etc.)
    • Order taxonomic name: (Trichoptera, Ephemeroptera, Plecoptera, Diptera, etc.)
    • Family common name:
    • Family taxonomic name:
    • Genus common name:
    • Genus taxonomic name:
    • Species taxonomic name:
    • Lifestage:
    • Sex:
     
  2. Mark Yoshida

    Mark Yoshida Active Member

    Perlodidae
    Skwala
    Stonefly
    Nymph stage
    Male - cuz of short wing?

    Just a guess.
    My boss asked what the heck I am doing.
     
  3. Taxon

    Taxon Moderator Staff Member

    Hi Mark Yoshida-

    Welcome to the party. Yes, it's the nymphal lifestage of an aquatic insect. And yes, it's a male, but not for the reason given. However, it's not stonefly, so it can't be of family Perlodidae, nor can it be of genus Skwala.

    IDENTIFICATIONS
    • Order common name: (Caddisfly, Mayfly, Stonefly, True Fly, etc.)
    • Order taxonomic name: (Trichoptera, Ephemeroptera, Plecoptera, Diptera, etc.)
    • Family common name:
    • Family taxonomic name:
    • Genus common name:
    • Genus taxonomic name:
    • Species taxonomic name:
    • Lifestage: Nymph (Mark Yoshida)
    • Sex: Male (Mark Yoshida)
     
  4. tkww

    tkww Member

    It's a mayfly, and I'm guessing in the family baetidae?
     
  5. Patrick Gould

    Patrick Gould Active Member

  6. Patrick Gould

    Patrick Gould Active Member

    Baetis bicaudatus
     
  7. Taxon

    Taxon Moderator Staff Member

    Hi twkk-

    Yes to both mayfly and family Baetidae.

    IDENTIFICATIONS
    • Order common name: Mayfly (twkk)
    • Order taxonomic name: (Trichoptera, Ephemeroptera, Plecoptera, Diptera, etc.)
    • Family common name:
    • Family taxonomic name: Baetidae (twkk)
    • Genus common name:
    • Genus taxonomic name:
    • Species taxonomic name:
    • Lifestage: Nymph (Mark Yoshida)
    • Sex: Male (Mark Yoshida)
     
  8. Taxon

    Taxon Moderator Staff Member

    Hi Patrick Gould-

    Yes, its common name is Blue-Winged Olive (BWO). Yes, it is of genus Baetis. No, it is not of species bicaudatus. Look closer. ;)

    IDENTIFICATIONS
    • Order common name: Mayfly (twkk)
    • Order taxonomic name: Ephemeroptera (Taxon)
    • Family common name: Small Minnow (Taxon)
    • Family taxonomic name: Baetidae (twkk)
    • Genus common name: Blue-Winged Olive (BWO)
    • Genus taxonomic name: Baetis (Patrick Gould)
    • Species taxonomic name:
    • Lifestage: Nymph (Mark Yoshida)
    • Sex: Male (Mark Yoshida)
     
  9. Mark Yoshida

    Mark Yoshida Active Member

    Male because of eyes size and front leg length?
     
  10. Patrick Gould

    Patrick Gould Active Member

    tricaudatus
     
  11. Taxon

    Taxon Moderator Staff Member

    Yes, definitely because of the eyes on this mature nymph, which is close to emerging based on its dark wingpads. However, only the imago (spinner) mayfly lifestage has extremely long forelegs, which are used to hold its female partner during copulation.
     
  12. Taxon

    Taxon Moderator Staff Member

    Yes, Baetis tricaudatis. Very good, Patrick. :)

    For others reading this, bicaudatis refers to only two caudal filaments (tails), whereas tricaudatis refers to three caudal filaments. The middle tail of this nymph, which is approximately 75% as long as the outer two, is so close in color to that of the background, as to be it difficult to see in the photo, unless one looks really closely.

    • Order common name: Mayfly (twkk)
    • Order taxonomic name: Ephemeroptera (Taxon)
    • Family common name: Small Minnow (Taxon)
    • Family taxonomic name: Baetidae (twkk)
    • Genus common name: Blue-Winged Olive (BWO)
    • Genus taxonomic name: Baetis (Patrick Gould)
    • Species taxonomic name: tricaudatus (Patrick Gould)
    • Lifestage: Nymph (Mark Yoshida)
    • Sex: Male (Mark Yoshida)
     
  13. jwg

    jwg Active Member

    What size is this nymph?
    Jay
     
  14. Taxon

    Taxon Moderator Staff Member

    Hi Jay,

    The body length was 8 mm. (~5/16 in.) from front of head to end of abdomen, not including the tails, which is how mayfly body length is measured.
     
  15. jwg

    jwg Active Member

    I had no idea a BWO species could be that large!

    I am enjoying this this flyfishing entomology

    please keep up the challenges!
     
  16. Taxon

    Taxon Moderator Staff Member

    hi jwg-

    Yes, the mature nymphal length range for those families, genera, and species (which flyfishers have given a common name of BWO) can run from ~3 mm to ~11 mm. The ones (of which I'm aware) are listed below:

    Scientific Name (Family) Mature Nymphal Length

    Apobaetis futilis (Baetidae) 3 mm - 3.5 mm
    Plauditus dubius (Baetidae) 3 mm - 5 mm
    Acentrella turbida (Baetidae) 4 mm - 6 mm
    Baetis bicaudatus (Baetidae) 4 mm - 5 mm
    Baetis flavistriga (Baetidae) 4 mm - 6 mm
    Baetis tricaudatus (Baetidae) 4 mm - 9 mm
    Iswaeon anoka (Baetidae) 4 mm - 5 mm
    Plauditus punctiventris (Baetidae) 4 mm - 6 mm
    Procloeon simile (Baetidae) 4 mm - 6 mm
    Ephemerella excrucians (Ephemerellidae) 5 mm - 9 mm
    Attenella attenuata (Ephemerellidae) 6 mm - 8 mm
    Attenella margarita (Ephemerellidae) 6 mm - 8 mm
    Baetis brunneicolor (Baetidae) 6 mm - 10 mm
    Ephemerella dorothea (Ephemerellidae) 6 mm - 9 mm
    Drunella lata (Ephemerellidae) 6.5 mm - 9 mm
    Dannella simplex (Ephemerellidae) 7 mm - 9 mm
    Drunella flavilinea (Ephemerellidae) 7 mm - 11 mm
    Drunella walkeri (Ephemerellidae) 8 mm - 11 mm
    Procloeon ingens (Baetidae) 8 mm - 9 mm
    Dannella lita (Ephemerellidae) 9 mm - 11 mm

    Glad you are enjoying the challenges. It's also an effective way to increase one's knowledge and identification skills.