Close-up of a worker of the socially parasitic species Formica truncorum. Its dark head marking is typical for nanitic workers of this species, but not for normal sized ones. Photo: Jürg Sommerhalder.

  Part of: Neumeyer R, Sommerhalder J, Ungricht S (2021) First observation of an ant colony of Formica fuscocinerea Forel, 1874 invaded by the social parasite F. truncorum Fabricius, 1804 (Hymenoptera, Formicidae). Alpine Entomology 5: 23-26.