Semiochemical lures known to attract Zygaenidae species were screened by means of sticky Delta traps and CSALOMON® VARL funnel traps in two Natura 2000 protected areas in Bulgaria - Nikopolsko plato (near Lozitsa village) (northern central Bulgaria) and Lozenska planina Mts, in 2015-2018 and 2023, respectively. As a result, Rhagades (Rhagades) pruni, Theresimima ampellophaga, Zygaena (Agrumenia) carniolica and Z. (Zygaena) filipendulae were recorded in the vineyards near Lozitsa vill. while Adscita (Eurasiterna) geryon, A. (Tarmannita) mannii, Jordanita (Tremewania) notata and Rh. (Rh.) pruni were registered in Lozenska planina Mts. Rhagades (Rh.) pruni was newly recorded in northern central Bulgaria. In addition to Zygaenidae species, a total of 62 non-target species belonging to following Lepidoptera families: Coleophoridae, Crambidae, Erebidae, Gelechiidae, Geometridae, Noctuidae, Nolidae, Nymphalidae, Oecophoridae, Pieridae, Plutelliidae, Pyralidae, Tortricidae and Yponomeutidae, were recorded. Sex attractants for one Coleophoridae, one Cambidae, one Geñechiidae and two Noctuidae species were established for the first time. Two Augasma species are new records for the fauna of the Balkan Peninsula.

Results from two collecting nights in central-eastern and central Albania are presented. One genus (Docirava Walker, 1863) and two species (Docirava dervenaria and Horisme radicaria) are new to the Albanian fauna. Some other species are reported for a second or third time in the country. Altogether, data for 126 species of Lepidoptera from 2 localities are presented here, and habitats, some specimens, and their genitalia are illustrated in 37 figures.

The results of two entomological expeditions conducted in September-October 2025 near Mali me Gropa (Central Albania) concerning Macroheterocera are presented. One genus and three species are new for Albania, nine species are reported for the second time from the country. Among the new species, Gortyna borelii lunata (Freyer, 1838) is from Appendices II and IV of the EEC 92/43 Habitats Directive, while Nothocasis rosariae Scalercio, Infusino & Hausmann, 2016 is recorded for the second time from the Balkan Peninsula. The highest altitudes and the southernmost observation of Gortyna borelii lunata are also presented. For thirty other species, third and fourth reports for Albania are announced. Comprehensive literature sources are gathered to all 122 reported species.

New and interesting records of Balkan Lepidoptera are detailed. One genus and three species are new for the Balkan fauna, one of them, Chondrosoma fiduciaria Anker, 1854, is a species from Annex II of the EEC 92/43 Habitat Directive. Two other species and one subspecies are proven to be a part of the Balkan fauna. The majority of the species are from the informal group “Macrolepidoptera”, but we include as well as some representatives of the informal group “Microlepidoptera”. Seven genera and 33 species and one subspecies are new for Albania, and 20 species are reported for the second time. For Montenegro, three genera and 12 species are new. Three species are new for the Republic of North Macedonia, and the second locality is reported for three other species. The genus Sympistis and nine species are new and five species are reported for the second time for Serbia. One genus and three species are new to Bulgaria and five are reported for the second time. One genus and two species are new for Bosnia and Herzegovina. One genus and three species are new for Greece. Altogether, data for 442 species of Lepidoptera from more than 120 localities are presented here, and selected habitats, specimens, and their genitalia are illustrated in 359 figures.

With the advancement of high-throughput, cost-effective sequencing, the application of genomic approaches to biodiversity research is becoming increasingly accessible and inclusive. As the availability of a reference genomes database is indispensable for genomics research, a recent pan-European effort - the European Reference Genome Atlas (ERGA) - was established to scale up the generation of high-quality reference genomes for European eukaryotic biodiversity. Here, we report the results from the GENBUL project, funded by the EU Horizon Europe BGE-ERGA Consortium to support the sampling of reference genomes from biodiversity hotspots in Bulgaria. Focusing on two key biodiversity areas, Slavyanka and Southern Pirin mountains (including the Nature Reserve "Alibotush") and the Strandzha Nature Park, we successfully sampled 190 plant and insect species, including several Bulgarian and Balkan endemics. This effort represents the first major effort for broader-scale genome referencing from Bulgaria and makes an important contribution towards local capacity-building in biodiversity genomics. However, considering the complexity of the genome sampling workflows, standards and metadata management, the GENBUL project also enabled to pinpoint major challenges, currently hindering the deployment of large-scale reference genome sampling in Bulgaria. Based on this experience, we outline key capacity, knowledge and research culture barriers faced by Bulgarian scientists and make recommendations to the international genomics research community for mitigation actions, also applicable to other Southeast European countries.

New and interesting records of Balkans Lepidoptera are detailed. Holoterpna pruinosata (Staudinger, 1897), recently known in Europe only from Crimea, was re-discovered in the Balkan Peninsula. Idaea sericeata (Hübner, 1813) is shown to be a part of the Balkan fauna. Pabulatrix pabulatricula (Brahm, 1791) is new for the Central Balkans. Two genera and four species are new and six species are reported for the second time for Albania. For Montenegro, one genus and four species are new and four species are recorded for the second time. One genus and four species are new for the Republic of North Macedonia. Three species are new and two are reported for the second time for Serbia. Four species are new to Bulgaria and 11 are reported for the second time. For many other species, third localities are reported for certain countries. For other species we report highest or lowest altitude localities and southernmost/easternmost points of their range. Data for some other interesting species from these countries and Greece are also presented, including new localities for species with poorly known distribution in the Balkan Peninsula and Balkans countries. Illustrations of specimens and their genitalia are given when necessary. Altogether data for 267 species of Lepidoptera are presented here, with 200 figures of habitats, specimens and their genitalia. In addition one Tachinidae (Diptera) parasitoid is new for Albania, and a new host species is reported for it.

Paracossulus thrips (Hubner, 1818) is a protected species in Europe through the Council Directive 92/43/EEC. Pupal exuviae belonging to this species were found at each of two patches at Chepan Mt. (Western Bulgaria) characterised by Phlomis tuberosa L. being a dominant plant species. This is the first record of this host plant of P. thrips in Bulgaria. Habitat types are provided for both patches of the host plant. Searching for exuviae is discussed as a preferred technique for monitoring this moth species.

Paracossulus thrips (Hübner, 1818) and Lignyoptera fumidaria (Hübner, 1825), both species listed on Annex II of the Council Directive 92/43/EEC, are reported for the first time for Serbia from two distinct localities on Vidlič Mt. Some new localities from the edge of the range of both these species are reported from Bulgaria. Previous reports of these species in the Balkan Peninsula are summarized and comments are given on the habitats, threats and conservation requirements of both species. Serbian vernacular names for both species are proposed.

Field work conducted in 2016-2019 and 2022 contributed with additional data on 23 relatively rare species in Albania, including the second record of Cacyreus marshalli and the sixth record of Apatura metis. Several new localities are given for Danaus chrysippus, which proved to be not rare on the southern coast of Albania.

The Balkan mountain ranges represent the most diverse hot spots of the European biodiversity still very far from being completely explored. Besides new faunistic data here we have described Drusus gornistok Oláh, sp. nov. in the D. discophorus species complex, surveyed four species complexes and described Polycentropus maglic Oláh, sp. nov. , P. staraplanina Oláh, sp. nov. in the Polycentropus ierapetra new species complex; Rhyacophila albanica Oláh & Ibrahimi sp. nov., R. montenegra Oláh, sp. nov. , R. syrikaltera Oláh & Ibrahimi sp. nov. in the Rhyacophila balcanica new species complex; R. kozara Oláh, sp. nov. , R. sarplana Oláh, sp. nov. , R. staraplana Oláh, sp. nov. in the Rhyacophila bosnica new species complex; Notidobia kerkina Oláh, sp. nov. , N. koraba Oláh, sp. nov. , N. lakmosa Oláh, sp. nov. , N. vaillanti Oláh, Vinçon & Ibrahimi sp. nov. in the Notidobia nekibe new species complex. The subspecies status of the following taxa were raised to species rank: Polycentropus adana Sipahiler, 1996 stat. nov., P. anatolica Sipahiler, 1989 stat. nov., P. dirfis Malicky, 1974 stat. nov., P. ikaria Malicky, 1974 stat. nov., P. isparta Sipahiler, 1996 stat. nov., P. kalliope Malicky, 1976 stat. nov., P. septentrionalis Kumanski, 1986, stat. nov., P. slovenicus Malicky, 1998 stat. nov.

Our main goal was to investigate the phylogeography of the butterfly Phengaris arion to reveal the evolutionary origin of its ‘spring’ and ‘summer’ forms. Molecular analyses based on highly variable microsatellites, together with Wolbachia screening, were carried out on 34 populations in Europe. We found three well-defined genetic lineages of different origins: the Apennine, the central and the eastern. The highly distinct Apennine lineage is limited by the Alps and evaluated as an Evolutionary Significant Unit (ESU). Therefore, the taxon name ligurica, described from the Ligurian coast (Italy), should not be applied to denote the ‘summer form’ of the Pannonian region. The central lineage is limited by the Carpathians and the most eastern ranges of the Alps, and lacks major range fluctuations related to glaciations, although there is evidence for extra-Mediterranean refugia in the Carpathian Basin. The eastern clade could have had refugia in central Asia. Our results exclude the potential allopatric origin of the ‘spring’ and ‘summer’ arion, and support the hypothesis that the existence of the two forms could be a result of local adaptation to the distinctive phenology of host plant flowering which is manifested in the genetic differences between them. Wolbachia infection has been ruled out as a driver of sympatric speciation in P. arion.

A new species, Dyscia intermedia sp. n., is described from the Balkan Peninsula, Serbia. Dyscia intermedia sp. n. differs from the other European members of the genus Dyscia Hübner, 1825 notably in the male genitalia, including the everted vesica. The new species is very similar in appearance to Dyscia raunaria (Freyer, 1851) and Dyscia royaria Tautel & Billi, 2006 and rather less so to Dyscia conspersaria ([Denis & Schiffermüller], 1775), but the differences in the genitalia are sharply prominent and constant and after examination of genitalia these species can be easily split. The differences in the genital features between the new species and D. raunaria and D. conspersaria are more prominent than between D. raunaria and D. royaria. Dyscia intermedia sp. n. is potentially an endemic species, found in three closely situated localities in eastern Serbia.

A new taxon Oncocnemis michaelorum srnkai Beshkov, ssp. n. is described from the Balkan Peninsula, Bulgaria. The new subspecies, in comparison with the other European members of the Oncocnemis confusa (Freyer, [1839]) species group, shows differences both in outward appearance and in the female and male genitalia, including the everted vesica. Oncocnemis michaelorum srnkai Beshkov, ssp. n. is a local endemic race, found in three localities close to each other ca. 30 km NW of Sofia. It is abundant in the type locality.

Perizoma obsoletata (Herrich-Schäffer, 1838) is shown to be a part of the Balkan fauna. Pabulatrix pabulatricula (Brahm, 1791) is new for the Western Balkans. One genus and 12 species are new and 20 species are reported for the second time for Albania. For Montenegro, one genus and eight species are new and two species are recorded for the first time. One genus and four species are new for the Republic of North Macedonia and another five species are reported for the second time from that country. One genus and three species are new for Bosnia and Herzegovina. Four species are reported for the second time and two for the third time for Serbia. Localities for Charissa pfeifferi (Wehrli, 1926) in Bulgaria are recorded for the first time. Data for some other interesting species from these countries and Greece are also presented. Most specimens were collected at light in 2019. Illustrations of specimens and their genitalia are given when necessary. Everted vesicas of some Geometridae species are illustrated for the first time.

An updated distribution of the genus Chersotis Boisduval, 1840 in Croatia, Albania and Bulgaria is presented. A total of seven species have been recorded in Croatia so far, with Chersotis laeta leonhardi (Rebel, 1904) being recorded for the first time during this survey. Chersotis laeta achaiana Thurner, 1967 is reported as new for Albania. The record of Chersotis fimbriola (Esper, [1803]) is marked as questionable for Croatia and Bulgaria as no exact locality is given nor is the specimen available for inspection for Croatia and the origin of the Bulgarian specimen is a case of doubt. For all other six species from Croatia an update in their distribution in the country is given. Additionally, all the species of the genus Chersotis occurring in Croatia have been barcoded and the results concur to the species identification based on the external and internal characteristics. Three taxa, Chersotis elegans (Eversmann, 1837) and Ch. laeta leonhardi from Croatia and Ch. laeta achaiana Thurner, 1967 from Albania have been DNA barcoded for the first time while for Chersotis laeta macini Rákosy, Stangelmaier & Wieser, 1996 a partial DNA barcode sequence was obtained.

The Balkan Lepidoptera fauna is still not comprehensively known. We present here some new records for three Balkan countries. Polymixis xanthomista (Hübner, [1819]) is confirmed for the Balkan Peninsula from Albania, Eriogaster inspersa Staudinger, 1879 is reported new for the Republic of North Macedonia (second locality in Europe), and Mythimna languida (Walker, 1858) is new for Bulgaria. Some other species (Ctenoplusia accentifera (Lefèbvre, 1827), Anchoscelis luteogrisea (Warren, 1911), Griposia bouveti pinkeri (Kobes, 1973) and Egira anatolica (Hering, 1933)) are confirmed for these countries. We provide illustrations of the species and their genitalia when necessary for confirmation.

Although the Sakar Mountain in Bulgaria is very rich in terms of biodiversity, there are no published data on the fauna of the family Zygaenidae in this area. The aim of the present study is to enhance the knowledge about the species diversity of Zygaenidae in the Sakar Mt. and to provide information about rare species of conservation concern. Nine localities were studied during two field trips in 2019. Altogether 13 species were found, the most interesting of which were Rhagades amasina as a new species for Bulgaria and Theresimima ampellophaga, Zygaena diaphana and Z. laeta, which are known to be relatively rare in the south-eastern Bulgaria, north-eastern Greece (Greek Thrace) and Turkish Thrace.

Acasis appensata (Eversmann, 1842) (Lepidoptera, Geometridae) is reported in Serbia for the first time. The status on the Balkan Peninsula of the two Western Palaearctic species of Acasis Duponchel, 1845 is discussed. The localized distribution pattern of both A. appensata and A. viretata (Hubner, 1799) is probably genuine, though both species may be significantly under-recorded for want of adequate field workers in the region.

Theresimima ampellophaga (Bayle-Barelle, 1808) was known from only three sites in North Macedonia and has never been considered as a pest of grapevine in this territory. The last time it was recorded in North Macedonia about 80 years ago. Traps baited with synthetic sex attractant EFETOV-2 (racemic mixture of (2R)-butyl 2-dodecenoate and (2S)-butyl 2-dodecenoate) were set at two localities near Ohrid Lake at Trebenishta village and between Ljubanishta village and Sveti Naum Monastery in 2016, in Vardar river valley near Demir Kapija in 2017 and near Dojran Lake in 2018. In North Macedonia sex attractants were used for the detection of this species for the first time. We recorded Th. ampellophaga in traps at all four monitored localities.