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

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

 

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

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

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)

 

It's a mayfly, and I'm guessing in the family baetidae?

 

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)

 

BWO

 

Baetis bicaudatus

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)

 

Baetis bicaudatus

 

Male because of eyes size and front leg length?

 

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.

 

tricaudatus

 

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)

 

What size is this nymph?
Jay

 

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.

 

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

I am enjoying this this flyfishing entomology

please keep up the challenges!

 

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

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

I am enjoying this this flyfishing entomology
please keep up the challenges!

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