A French Carabus specialist, André Lequet, who has a lot of experience with this species, pointed out that this specimen is very likely to be a natural hybrid between Carabus rutilans and Carabus hispanus, which is called 'croesus'. Interbreeding experiments have proved that the female 'croesus' specimens can be fertile. When they mate successfully with 'hispanus' or 'rutilans' males, their offsping can have again features resembling very closely a 'hispanus' or 'rutilans'. According to André Lequet who did several interbreeding experiments, this specimen looks very similar to a 'croesus' from several generations old, with a dominance of the 'rutilans' characteristics.