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

Background: The Bulgarian myrmecofauna is one of the richest in the Balkans. This is a result of both the physicogeographical and paleoecological features of the area, as well as relatively well-studied fauna. The earliest myrmecological paper on Bulgarian fauna, listing 54 species, was published 130 years ago.

The role of ant nests in European ground squirrel's () post-reintroduction adaptation in two Bulgarian mountains.

The European ground squirrel () is a vulnerable species, whose populations are declining throughout its entire range in Central and South-Eastern Europe. To a great extent, its conservation depends on habitat restoration, maintenance and protection. In order to improve the conservation status of the species, reintroductions are increasingly applied.

Terrestrial gastropods of Srebarna Nature Reserve, North-Eastern Bulgaria (Gastropoda).

We give the results from the first investigation focused on the land snail fauna in Srebarna Nature Reserve in Bulgaria. A total of 23 localities were studied and 27 species of terrestrial gastropods were found, 23 of which were new observations for the Reserve.

Catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria.

The present catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria is made on a base of critical reconsideration of literature (covering the period from 1892 till 2009 and part of 2010) as well as on examination of the authors' and several museum's collections. A lot of data were omitted in the previous Bulgarian monograph on ants, lots of new data were recently added and many important additions and alterations were made due to taxonomic revisions of Eurasian Formicidae during the last three decades. Two new species are reported for the country [Temnothorax graecus (Forel, 1911) and Temnothorax cf.