I'm not an authority, but one of my previous posts helps shed a little light on how to define (and redefine) species:
http://www.nanfa.org/archive/nanfa/nanfa-lmar05/0072.html
Also, don't forget about NANFA's taxonomically up-to-date checklist of species, subspecies and undescribed forms:
http://www.nanfa.org/bccdiversity.shtml
Chris Scharpf
NANFA HQ
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