Abstract: Myrmicinosporidium durum HÖLLDOBLER, 1933, a fungus parasitizing various ant species, has been found only sporadically. During a collecting trip in April 2004, we have found a couple of infected colonies of Temnothorax albipennis (Curtis, 1854) and one of Chalepoxenus muellerianus (Finzi, 1922) in the Italian region of Abruzzo. Two colonies of the slave-maker Chalepoxenus muellerianus with host workers [T. unifasciatus (Latreille, 1798)] bearing the infection had been found near the Garda Lake in the Italian Alps in 2003. On 4 September 2004 the infection appeared in workers and in swarming gynes of Solenopsis fugax (Latreille, 1798) at Darmstadt, Germany, which is the first record north of the Alps since more than 70 years after its description from Würzburg, Germany. We report these recent findings because nothing is known yet on the way of infection, although there are data on the range of the fungus. It has been described from southern Germany, later was found in several Mediterranean countries (Italy, Spain, the former Yugoslavia). The same, or a closely related species of fungus had been recorded from Texas, Usa, and from the Galapagos Islands. A couple of Temnothorax species and their social parasite Chalepoxenus muellerianus, two species of Pheidole (France and Galapagos), Solenopsis fugax (Europe), and one species of Pogonomyrmex (USA), all Myrmicinae, but also Plagiolepis spp. (Formicinae), are known as host species so far. In 2004 another two species of Solenopsis, two Pheidole, Pogonomyrmex badius (Latreille, 1802), Paratrechina vividula (Nylander, 1846), and Pyramica membranifera (Emery, 1869) from Usa had to be added.