An updated checklist of ants (Hymenoptera, Formicidae) of Bulgaria, after 130 years of research

Further records of social parasitic ants in Europe and review of the Bulgarian species

Background

Social parasitic ants exploit the colonies of other ant species, either permanently or temporarily. The permanent parasites are amongst the rarest species of ants, although their hosts may be very common. Due to their rarity and often restricted distribution range, most of them are listed as vulnerable. Filling in the gaps in geographical and host ranges will advance our understanding of the social parasitic lifestyle's origin and evolution.

New information

This study reports the first records of the slave-makers Myrmoxenusalgerianus (Cagniant, 1968) for Europe (Italy, Sicily) and M.ravouxi (André 1896) for Albania and the inquiline Anergatesatratulus (Schenck, 1852) for Malta (Gozo). We also report new localities of Camponotusuniversitatis Forel, 1890 for Albania and Myrmoxenusgordiagini Ruzsky, 1902, M.kraussei (Emery, 1915) and Anergatesatratulus for Bulgaria. Diversity, type of parasite-host relationships, host range, distribution and conservation of social parasitic ant species in Bulgaria are discussed. Although social parasitic ants are still understudied in Bulgaria, they represent 21% of the regional ant fauna.

Fungi Associated with Messor Ants on the Balkan Peninsula: First Biogeographical Data

Ant nests’ relatively stable and long-lasting microhabitats present ideal living conditions for many uni- and multicellular organisms, whose relationships range from mutualistic to parasitic. Messor harvester ants inhabit arid and semi-arid open areas where their colonies consist of large numbers of individuals. Due to the high number of other organisms associated with harvester ants, their nests can be defined as islands for unique biota. Despite significant progress in research on ant-associated fungi in Europe, little is still known about the recently described ectoparasitic fungus Rickia lenoirii Santamaria, 2015 (Laboulbeniales), found on two species of ants of the genus Messor. Here we report for the first time the occurrence of the ectoparasitic ant-associated fungus R. lenoirii from three countries (Albania, Bulgaria, and continental Greece) and multiple localities in the Balkans. The fungus was detected on four ant host species—Messor structor (Latreille, 1798), M. wasmanni Krausse, 1910, M. hellenius Agosti & Collingwood, 1987, and M. mcarthuri Steiner et al., 2018 with the latter two representing new host records. Furthermore, spores of the widespread endoparasitic fungus of ants, Myrmicinosporidium durum Hölldobler, 1933 (Blastocladiomycota), were reported for the first time in Messor structor (Bulgaria). Images of the ant-associated Rickia lenoirii taken with a scanning electron microscope, a comparison with R. wasmannii, and a distribution map are also presented.