Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
Just to add to Gonzo's assessment of characteristics, A. capitata is identified most definitively by looking at the dark pigment on tergum 10 as well as the head pattern. With this species, the pigment band on tergum 10 is uninterrupted (though it narrows quite a bit). The head "M line" is nearly lateral, as apposed to A. flavescens, for example, which really looks like an M with posterolaterally directed arms.
Troutnut on Mar 23, 2011March 23rd, 2011, 6:41 am EDT
Yes, I collected it. I don't go pulling legs off my bugs at random, so the leg must have been missing when I found it in my sample tub. However, I sample with a kick-net, which is kind of a rough process for the bugs, so it could have been lost during that. I've also had bugs lose limbs to predators in my bucket/tub, but that's unlikely for a stonefly this size.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Jmd123 on Mar 23, 2011March 23rd, 2011, 8:58 am EDT
We handled our bugs pretty roughly during our last project (oil-polluted streams in north Toledo) and I am surprised that more of them didn't end up being damaged. The vast majority of them were perfectly intact, even after we had to subsample and thus give them another round of rough handling. Perhaps attacked by a crayfish or small fish? Or a fight with another stonefly nymph?? Crayfish will go after each other pretty good and tear off limbs.
Again, what a beautiful insect. It makes me glad that I went into entomology. Too many people miss the wonders of the natural world which is all around them, sometime in quite tiny form. A good microscope helps. Gotta take time to "smell the roses".
No matter how big the one you just caught is, there's always a bigger one out there somewhere...