New parasitoid (Hymenoptera, Chalcidoidea) records of bark beetles (Coleoptera, Curculionidae, Scolytinae) in pine plantations in Bulgaria.

Background: In 2020 and 2021, chalcidoid parasitoids (Hymenoptera, Chalcidoidea) of bark beetles in pine (Pinus spp.) plantations were studied in Bulgaria. Samples (cuttings of stems and branches) of pine trees infested by bark beetles were collected from seven plantations of Pinussylvestris and P.nigra in Bulgaria. From each sampling plot, five cuttings were collected and placed in photoeclectors in laboratory conditions (18-22ºC). Emerged bark beetles and parasitoids were regularly gathered and fixed in ethanol. New information: Six parasitoid species - Dinotiscuscolon, Metacolusazureus, M.unifasciatus, Rhopalicusquadratus, R.tutela (Chalcidoidea: Pteromalidae) and Heydeniapretiosa (Chalcidoidea, Heydeniidae) were reared from five bark beetle hosts (Ipsacuminatus, Pityogenesbistridentatus, Pityophthoruspityographus, Tomicuspiniperda and T.minor). Amongst them, three species (H.pretiosa, M.azureus and R.quadratus) are recorded as new for Bulgarian fauna.

A checklist and areography of the longhorn beetles (Coleoptera, Cerambycidae) of Pirin Mountains, Bulgaria.

Background: The longhorn beetles fauna of Pirin Mountains, Bulgaria, was studied, based on literature data and original material. As a result, 100 taxa from five subfamilies are listed for the area, as follows: Prioninae (7 taxa), Lepturinae (31 taxa), Spondylidinae (9 taxa), Cerambycinae (28 taxa) and Lamiinae (25 taxa). New information: This study presents two new records for Pirin Mts. (Oxymiruscursor and Tetropiumfuscumfuscum) and new localities or additional information for 13 cerambycid taxa (species and subspecies). The 100 longhorn beetle taxa belong to 17 zoogeographical categories and eight complexes. The European complex occupies a dominant position (34%), followed by those from Palaearctic (17%), Eurosiberian (15%), Mediterranean (15%), European-Iranoturanian (9%), Balkan endemic (5%) and Holarctic (4%) complexes.

A checklist and areography of longhorn beetles (Coleoptera: Cerambycidae) in Rila Mountain.

BACKGROUND: The complex of longhorn beetles in Rila Mt. in Bulgaria was studied by literature data and original biological materials. As a result, 126 taxa from six subfamilies were established, as follows: Prioninae (four taxa), Lepturinae (43 taxa), Necydalinae (two taxa), Spondylidinae (seven taxa), Cerambycinae (31 taxa) and Lamiinae (39 taxa). NEW INFORMATION: In this study, two new records for Rila Mt. (Stenurellanigranigra and Xylosteusspinolae) and new localities or additional information for 24 cerambycid taxa were reported. The longhorn beetles belong to 18 zoogeographical categories and seven complexes. The European complex occupies a dominant position (37.3%), followed by the Palaearctic (23.8%), Eurosiberian (13.5%), Mediterranean (11.1%), European-Iranoturanian (7.1%), Balkan endemic (4.0%) and Holarctic (3.2%) complexes.

Biotic threats for 23 major non-native tree species in Europe.

For non-native tree species with an origin outside of Europe a detailed compilation of enemy species including the severity of their attack is lacking up to now. We collected information on native and non-native species attacking non-native trees, i.e. type, extent and time of first observation of damage for 23 important non-native trees in 27 European countries. Our database includes about 2300 synthesised attack records (synthesised per biotic threat, tree and country) from over 800 species. Insects (49%) and fungi (45%) are the main observed biotic threats, but also arachnids, bacteria including phytoplasmas, mammals, nematodes, plants and viruses have been recorded. This information will be valuable to identify patterns and drivers of attacks, and trees with a lower current health risk to be considered for planting. In addition, our database will provide a baseline to which future impacts on non-native tree species could be compared with and thus will allow to analyse temporal trends of impacts.

Worldwide Genetic Structure Elucidates the Eurasian Origin and Invasion Pathways of Dothistroma septosporum, Causal Agent of Dothistroma Needle Blight.

Dothistroma septosporum, the primary causal agent of Dothistroma needle blight, is one of the most significant foliar pathogens of pine worldwide. Its wide host and environmental ranges have led to its global success as a pathogen and severe economic damage to pine forests in many regions. This comprehensive global population study elucidated the historical migration pathways of the pathogen to reveal the Eurasian origin of the fungus. When over 3800 isolates were examined, three major population clusters were revealed: North America, Western Europe, and Eastern Europe, with distinct subclusters in the highly diverse Eastern European cluster. Modeling of historical scenarios using approximate Bayesian computation revealed the North American cluster was derived from an ancestral population in Eurasia. The Northeastern European subcluster was shown to be ancestral to all other European clusters and subclusters. The Turkish subcluster diverged first, followed by the Central European subcluster, then the Western European cluster, which has subsequently spread to much of the Southern Hemisphere. All clusters and subclusters contained both mating-types of the fungus, indicating the potential for sexual reproduction, although asexual reproduction remained the primary mode of reproduction. The study strongly suggests the native range of D. septosporum to be in Eastern Europe (i.e., the Baltic and Western Russia) and Western Asia.