This is my attempt at a Visual Key. The wrinkle is that it’s in monochrome (mainly). Monochrome may strike many as odd so why monochrome?
I have lost count of the number of times I’ve come across folks being confused by colours which appear not to match those in a book. The fact is that individuals display some natural colour variation anyway. More misleading though is the fact that the colours of several species differ markedly by maturity, either being completely different or just “washed out” when immature or darkening considerably as they age.
There are generally markings and features, however, which do not change with age. My use of monochrome is an attempt to force the observer to concentrate on these constants rather than on colour which may mislead. I slip into colour only as a last resort and when I think it safe to do so.
Traditional keys tend to be written for a specimen in the hand and a lens. Where possible, I have avoided some of those factors in favour of larger, more visible features that should help those armed only with photographs.