This is a question that has plagued me for months, and I've never asked until now. Leptothorax canadensis is so weird, and sometimes i have trouble believing that two ants collected in different areas are of the same species.
When I drove north this summer, I collected some L. canadensis in the area. They were incredibly bicolored (Orange or bright red thorax), nested in small crevices in stones (most often pumice or other volcanic rock), and were somewhat larger than the average Leptothorax. In contrast, L. canadensis which occurs in the lower mainland is often jet black (or muddy red), nests most often in logs, and are incredibly shy and inconspicuous. This is purely anecdotal, but nevertheless, those were the main differences I have observed in both ants. Obviously they both behave as Leptothorax and they are both largely similar.
Is there any reason for this diversity or did these ants evolve this way? I doubt Lasius americanus or Temnothorax longispinosus have such striking physical differences based on locality.
Or did I just find L. acervorum?