I've been looking through a hundred old AES Bulletins to see if I can find darkling beetle articles and just a few minutes after your post I looked through a couple and happened to see a photo of a group of your bugs, taken in France, in the October 94' issue. They are firebugs (Pyrrhocoris apterus). On a side note, I've only come across two short paragraphs on darklings in one issue and never realized before how many articles they have on just ones beetle species, Lucanus cervus.