Максим Гуляев:

Enrico Schifani:
Hi, it's Formica truncorum the very dense, yellowish hairs (more evident in the high resolution picture on the comment link) are unique to this species. You can also notice the elongated funicular segments which can also be considered as an important character. Pigmentation is by the way averagely more reddish and less blackish than in the other European species of the rufa group.