Diversity of Myrmecophilous Silverfish (Insecta: Zygentoma) in Bulgaria

Silverfish (order Zygentoma) comprise a diverse group of primitively wingless insects, several of which have evolved myrmecophilous associations with ants (Hymenoptera: Formicidae). However, the diversity and host relationships of ant-associated Zygentoma in the Balkans remain insufficiently documented. In this study, we surveyed ant nests across Bulgaria to assess the taxonomic diversity, host specificity and distribution of silverfish associated with ants. We identified five species: Atelura montana (Stach, 1946), Proatelurina pseudolepisma (Grassi, 1887), Neoasterolepisma balcanicum (Stach, 1922), N. cf. crassipes (Escherich, 1905) and N. wasmanni (Moniez, 1894). These species were recorded from nests of ants belonging to the genera Bothriomyrmex, Aphaenogaster, Pheidole, Messor, Tetramorium, Formica and Lasius. Patterns of host association ranged from generalist species occurring in nests of multiple ant genera, such as Atelura montana, to more specialised taxa largely restricted to a single host genus, as observed in Neoasterolepisma species. Our findings expand the current understanding of myrmecophilous Zygentoma in the Balkans. Three species—Proatelurina pseudolepisma, Neoasterolepisma cf. crassipes, and Neoasterolepisma wasmanni—are reported here for the first time in Bulgaria, bringing the total number of recorded silverfish species in the country to 11. Moreover, our results highlight the ecological importance of ant nests as microhabitats that support highly specialised arthropod communities.