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3. From Hook-up to Hand, Page 2

Shawn-

I know you're probably just pulling my chain, and already know this anyway. However, hind wing costal angulation and wing venation are two different things, although both are reasonably usable keys that can help flyfishers to identify mayflies, particularly with the magnification aid of a loupe.

Mayflies wings often have quite visible veins, which are an important structural element of the wing for the mayfly, and can be a useful identification key for the flyfisher. The large veins running from the base to the tip of the wing are called longitudinal veins. The smaller veins, which run (more or less) perpendicular to the longitudinal veins are called cross veins. And, the open areas bordered by these two kinds of veins are called cells.

The comment, which I made about "costal cells" was an attempt to refer to the (somewhat) unusual cells formed by the 1st longitudinal vein (called the costa), the 2nd longitudinal vein (called the subcosta), and the cross veins that connect them, in that particular specimen photo.

Hind wing costal (angulation or projection) has to do with the shape of the leading edge of the hind wing in the immediate proximity of the wing's base. Identification to family (or genus) can often be aided by recognizing the nature of this shape, which may be straight, rounded, angled, pointed, knobbed, hooked, etc.

My hope is that this explanation will help clarify some of the (admittedly) cryptic terms I may have carelessly used. On the other hand, I suppose there's at least an equal chance, that I'll only succeed in further muddying of the water. Sorry if that's the result.

No, Roger, there's no chain-pulling going on here, just using one example among a thousand in which I didn't know the first thing about what was being said. I'm still having trouble remembering the Latin names of the 5 most important mayflies on my local streams. I'm not fond of memorizing, and I'm really much more interested in flytying than I am in entomology (though I am making a modest effort to put aside my druthers and learn a little entomology, knowing that doing so could help improve my tying and fishing). So my comments were completely sincere - I have great respect for you guys who actually know something about insects and can apply it to fishing situations.

And my thanks for the introductory lesson on ID. I find the glossary on this site quite helpful, but there's nothing quite like having an expert put all the terms together for you. Now, if you ever get me to the point where any of the ID criteria you described actually help me differentiate insects when a hatch is going on, you'll have climbed a teaching Everest and I'll catch more fish.

Thanks,
Shawn