It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects.

Based on material collected between the years 1988-2015 numerous new province and country records of ants from Turkey are given. A total of 143 ant species were listed of which six: Cataglyphis machmalRadchenko & Arakelian, 1991, Lasius illyricus Zimmerman, 1935, Monomorium barbatulumMayr, 1877, Myrmica caucasicolaArnol'di, 1934, Temnothorax clypeatus (Mayr, 1853) and Temnothorax rogeriEmery, 1869 are new for Turkish ant fauna. Based on most recent taxonomic data and studies on distributional patterns we also excluded from Turkish ant fauna fifteen species: Bothriomyrmex corsicus Santschi, 1923, Anoplolepis gracilipes (F. Smith, 1857), Cataglyphis cursor (Fonscolombe, 1846), C. rubra (Forel, 1903), Lasius paralienusSeifert, 1992, Plagiolepis pallescens mauraSantschi, 1920, Proformica nasuta (Nylander, 1856), Aphaenogaster semipolita (Nylander, 1856), A. testaceopilosa (Lucas, 1849), Crematogaster aubertiEmery, 1869, C. scutellaris (Oliver, 1792), Solenopsis geminata (Fabricius, 1804), Temnothorax nylanderi (Förster, 1850), T. crassispinus (Karavaiev, 1926) and Tetramorium semilaeveAndré, 1883. Taxonomic position and new species names which were given in publications following the first Turkish checklist in 2012 are also discussed. The available faunal data showed that the ant fauna of Turkey is represented currently with 362 taxa.

The ant fauna of Greek Thrace has been least known of all Greek regions with only 12 species mentioned in the literature. We conducted two field trips to this region in 2014 and 2015 and included some unpublished ant material, thus compiling new records from 72 sampling localities. We found 115 ant species, 108 of them are recorded for the first time in Greek Thrace. Cataglyphis viaticoides, Temnothorax aeolius, Tetramorium cf. davidi, Tetramorium hippocratis, and Tetramorium rhodium were so far not known for continental Greece. In the checklist of recorded species, we also give information on the taxonomic status and distribution of certain taxa.

The first annotated checklist of the ants of Turkey is presented. A total of 306 valid names of species-group taxa (286 species, 20 subspecies) is recorded based on literature records and additional newly collected material carried out since 1998. Synonyms are included. New localities are added for some poorly known species. Four species (Tapinoma subboreale, Formica georgica, Formica lugubris and Lasius balcanicus) are reported for the first time and thirteen species (Bothriomyrmex atlantis, B. meridionalis, Tapinoma madeirense, Camponotus robustus, Formica fuscocinerea, F. gagatoides, Rossomyrmex minuchae, Messor barbarus, Monomorium glabrum, M. salomonis, Myrmica vandeli, Stenamma westwoodii and Tetramorium forte) are excluded from the list of Turkish ants.

The West-Palearctic region is a diversity hotspot for the ant genus Aphaenogaster. Species in this region are characterized by high morphological variation, which has led to their subdivisioninto different infrageneric groups. The very first classification in three subgenera, dated 1915, was gradually replaced by eight species-groups. To probe the evolutionary consistency of these species-groups, we sequenced 46 species from all eight species-groups and biogeographic sectors of the region, using one mitochondrial (COI) and six nuclear markers (EPICs), and interpreted the results by integrating qualitative morphology. Our results demonstrate the non-monophyly of all formerly recognized subgenera and species-groups, except for the crocea group. We use the phylogeny and morphological characters to propose a new classification of six monophyletic species-groups (crocea, gibbosa, graeca, pallida, sardoa, subterranea). The pallida, subterranea and sardoa (formerly testaceopilosa) groups attain monophyletic status by reassigning a few taxa. The gibbosa group is to be considered exclusively Western-Mediterranean until further assessments of similar Eastern species. The new graeca group is established by including former members of the splendida and subterranea groups, while the polyphyletic cecconii, obsidiana, and splendida groups are dismissed. Notably, the first is not part of the tropical Deromyrma clade as previously thought, while at least two independent clades which require further investigation are composed of species from both the cecconii and splendida groups, suggesting repeated morphological convergences based on similar ecological adaptations. Finally, A. cardenai is confirmed to be a significantly divergent lineage. In addition, three Aphaenogaster species are moved to different genera: Messor asmaae (Sharaf, 2018) comb. nov., Messor isekram (Bernard, 1977) comb. nov., and Pheidole sarae (Sharaf, 2018) comb. nov. Further studies should address the evolutionary relationships between the clades recovered in this study.

Members of the Aphaenogaster splendida group are reviewed. We recognize 12 species, of which three are new: A. hamaensissp. nov. (Syria), A. peloponnesiacasp. nov. (continental Greece), and A. vohralikisp. nov. (Turkey). Species status is restored for Aphaenogaster schmitziForel, 1910stat. rev., and Aphaenogaster transcaucasicaKaravaiev, 1926stat. nov. is raised to the species rank. Aphaenogaster schmitziForel, 1910 is recognized as a senior synonym of Aphaenogaster schmitzi syriaForel, 1910syn. nov. and Aphaenogaster ovaticepsEmery, 1898 is recognizes as a senior synonym of Aphaenogaster muellerianaWolf, 1915syn. nov. Detailed descriptions, measurements, habitat and nesting preferences, and activity of workers of all 12 species are given. Keys to workers and known gynes, and photographs of all species and their known castes are presented.