|Myrmica slovaca worker|
This specimen is clearly Myrmica slovaca, due to the narrow frons, scape and petiole shape. It was previously erroneously regarded as M. salina in Europe, but this was recently resolved by Radchenko and Elmes (2010), who found that it is quite different from true M. salina. Even so, the name may still be subject to some change, as Seifert (2011) suggests that M. curvithorax is the senior synonym. Currently, according to AntWeb, M. slovaca is still considered to be the correct name.
As far as I've been able to find out, M. slovaca was previously recorded only once in France (as M. salina) at Pont-à-Mousson in 2005, which is situated at approximately 6.03° E and was considered to be the western limit of the species range. This would make my collection, at 5°20.055'E, the new western extent of the species' range. Of course, there may now be other records of this species from France and I would be very pleased to receive further information.
You have to wonder though... I collected this in a rather unpromising looking motorway service station. Seifert (2007) notes the species' high tolerance for changes in humidity, temperature and soil salinity. Is it possible that it is being transported by people and its wide tolerance allows it to colonise a variety of sites? It certainly seems incredible that such a distinctive species had never been recorded in France before 2005.