Izvestia Sankt-Peterburgskoj lesotehniceskoj akademii
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Formation of a pest and disease complex of boxwood in Donbass
The data on the formation of a complex of phytophagous organisms and phytopathogens associated with evergreen boxwood (Buxus sempervirens L.) in Donbass are provided. Between 2008 and 2024, phytopathological surveys conducted in urban plantings of the region identified seven species of mycopathogens and five species of phytophagous insects associated with boxwood. These include four fungal species (Pseudonectria buxi (DC.) Seifert, Gräfenhan & Schroers, Dothiorella candollei (Berk. & Broome) Petr., Hyponectria buxi (Alb. & Schwein.) Sacc., Dothiora buxi Jayasiri, Camporesi & K.D. Hyde) and four insect species (Eriococcus buxi (Boyer de Fonscolombe, 1834), Psylla buxi (Linnaeus, 1758), Cydalima perspectalis (Walker, 1859), Monarthropalpus flavus (Schrank, 1996)) that specialized to feed on boxwood. Among the pathogenic fungi, only Pseudonectria buxi poses a potential threat to boxwood plantings. Within the complex of phytophagous insects, the penetration of Cydalima perspectalis into the region represents the most danger, as it has the potential to become the main species in the complex of boxwood pests. The harmful effects of the remaining species are primarily manifested in the overall weakening of the plants and a reduction in their ornamental value. In the context of climate change and the uncontrolled importation of planting material, an expansion of the complex of pests and diseases affecting boxwood in the region is anticipated. The primary vector for the invasion of phytophagous species and phytopathogens is the unintentional importation through planting material. To enhance the resilience of boxwood in urban plantings, it is essential to establish phytosanitary monitoring systems and implement a comprehensive set of agronomic, sanitary, and chemical protective measures. Currently, the use of boxwood in the landscaping of populated areas in Donbass should be limited, and phytosanitary control over imported planting material, as the primary source of invasion, must be strengthened.
Weevils (Coleoptera: Curculionoidea) associated with oak (Quercus) in the south of the Central Russian forest-steppe
The species composition and ecological features of the weevil complex associated with oak species (Quercus) in the southern part of the Central Russian forest-steppe within the boundaries of the Belgorod, Voronezh, Lipetsk and Tambov regions were studied. 63 species from three families were identified: Curculionidae excluding Scolytinae (47 species, or 74 % of the total number of species), Attelabidae (8; 13 %) and Anthribidae (8; 13 %). The isolation of the fauna of the Tambov region is explained by the relatively small area of oak stands in the region (15.7 % of all forested areas in the region) and insufficient study of the species composition of Curculionoidea. The faunas of Lipetsk and Belgorod regions have the greatest similarity (Jaccard coefficient 73 %) and high species diversity (46 and 51 species respectively). The fauna of Voronezh region is distinguished by the greatest species diversity (52 species) and relatively high similarity with the fauna of Lipetsk (Jaccard coefficient 66.0 %) and Belgorod (63 %) regions. The dominant species complex refers to the phyllobiont ecological group with mixed feeding groups (41 species; 65.0 %). The second place is occupied by kormobionts (14 species; 22.0 %); the third place – by carpobionts (4; 6.0 %). The species of these three groups make up 94.0 % of the oak weevil fauna. The role of blastobionts (2; 3.0 %) and teratobionts (2; 3.0 %) in the fauna structure is insignificant. Weevils are represented mainly by polyphages (51 species; 81.0 %); number of highly specialized species are significantly smaller – 9 for narrow oligophages 9 (14.0 %) and 1 for broad oligophage (2.0 %). Highly specialized monophages are represented by only two species (3.0 %). The far from complete study of the weevils’ fauna of the Central Russian forest-steppe and the complex trophic structure of the entire complex, including five main trophic groups and four groups with a mixed feeding pattern, indicate the need and prospects for further, more indepth development of these issues.
Camptosomata (Coleoptera: Chrysomelidae: Cryptocephalinae) of Rostov Region
A list of Camptosomata of the Rostov region is given for the first time. Fifty one species of this group belonging to the tribes Clytrini (6 genera, 13 species) and Cryptocephalini (3 genera, 38 species) were registered in the region. Clytrini includes the species Cheilotoma erythrostoma, Clytra atraphaxidis atraphaxidis, C. laeviuscula, C. quadripunctata, Coptocephala gebleri, C. unifasciata, Labidostomis beckeri, L. cyanicornis, L. longimana, L. pallidipennis, Smaragdina affinis, S. salicina, Tituboea macropus. Cryptocephalini includes the following species: Cryptocephalus anticus, C. apicalis, C. bameuli, C. bilineatus, C. bipunctatus, C. bohemius, C. chrysopus, C. coerulescens, C. connexus, C. cordiger, C. elegantulus, C. elongatus, C. ergenesis, C. flavicollis, C. flavipes, C. flexuosus, C. gamma, C. janthinus, C. labiatus, C. laetus, C. laevicollis, C. lateralis, C. moraei, C. octomaculatus, C. planifrons, C. pygmaeus, C. populi, C. sericeus, C. quariguttatus, C. quadripustulatus, C. violaceus, C. virens, Pachybrachis fibriolatus, P. mendax, P. scriptodorsum, P. tesselatus, Stylosomus cylindricus, S. flavus. The annotated list is supplemented with information on distribution and food preferences, features of larval stages of development. Among the Camptosomata of the Rostov region, species with Wide Eurasian types of ranges predominate, ranges of the Broad European type and others are less common. More than half of the listed species are polyphags on the imaginal stage. A smaller part consists of broad oligophags, narrow oligophags and monophags, mainly feeding on the families Asteraceae and Salicaceae.
Composition of dendro- and tamnobiont hemipterans (Heteroptera) in the former burnt areas of the Usmansky forest (Voronezh Region)
The article analyses the current composition of the complex of dendrobiont and thamnobiont hemipteran insects (Heteroptera) after the fire in 2010 in the Usman pine forest (Voronezh Region, East European forest-steppe) based on materials collected in 2014–2024. The compositions of hemipteran complexes of the monitoring polygon of post-pyrogenic succession with natural restoration of forest, the adjacent margin of the forest not affected by fire, and the area with mixed young plantings of pine and birch were compared. The total composition of hemipteran species includes 43 species from 11 families. On the elevated part of the polygon relief, 18 species from 9 families were identified. In terms of humidity requirements, mesophiles predominate here (72.2 % of species). The number of mesoxerophiles is 27.8 %, of which the phytophage Piezodorus lituratus and the predators Nabis pseudoferus and N. punctatus dominate in numbers. In terms of the number of species, horto-tamno-dendrobionts predominate – 33.3 %. In the depressions of the polygon, 15 mesophiles were recorded with the dominance of Kleidocerys resedae, Nabis ferus and Palomena prasina. The dendrobionts predominates (40 %). The most diverse hemipterocomplex is found in the forest margin area undamaged by fire (39 species), with the dominance of the predators Orius majusculus, O. minutus, O. niger, N. ferus, the zoophytophagous Heterocordylus genistae and the phytophagous Physatocheila smreczynskii. Dendrobionts predominate (35.9 %). The most depleted forest area is the one with artificial forest plantations, including 5 species from three families – predatory Nabidae (2), phytophagous Pentatomidae (2) and Lygaeidae (1). More than 70 % of all bugs collected in this area were K. resedae. The basis for the highest similarity rates of the Hemiptera complexes of the control forest area and the monitoring polygon (24 common species; Kj = 0.56; Ks = 0.72) is the diversity of habitats and tree and shrub species. In general, 14 years after the forest fire the natural reforestation regime provided an almost sixfold predominance of species diversity of dendro-tamnobiont hemipteran insects (Heteroptera) (28 species) compared to the same indicator in areas with artificial forest plantations (5 types).
Coleoptera of the Monotomidae family (Coleoptera, Cucujoidea) of Tula region
The work is the result of many years of research on Coleoptera of the Tula region. An annotated list for family Monotomidae Laporte, 1840 is provided. Currently, 15 species from 2 subfamilies and 2 genera have been registered in the Tula region. The subfamily Rhizophaginae Redtenbacher, 1845: 1. Rhizophagus aeneus Richter, 1820 (places of finds: Severo-Vatsevskoe forestry, Odoevsky district, 5.V-17.VI 2006; ibid., 5.V–21.V 2006); 2. Rh. bipustulatus (Fabricius, 1792) (places of finds: Tula, parks, squares, gardens, suburban area, wastelands; everywhere on the territory of zasek; Severo-Odoevskoe forestry, Odoevsky district, 7.V–27.V 2012; Deminka, Leninsky district, 3.V–26.V 2014); 3. Rh. cribratus (Gyllenhal, 1827) (places of finds: Yasnaya Polyana, Shchekinsky district); 4. Rh. depressus (Fabricius, 1792) (places of finds: Petrovskoye, Odoevsky district, 27.V–23.VI 2007); 5. Rh. dispar (Paykull, 1800) (places of finds: Selivanovo, Yasnaya Polyana, Shchekinsky district); 6. Rh. fenestralis (Linnaeus, 1758) (= parvulus (Paykull, 1800). (places of finds: Tula, parks, squares, gardens, suburban area; Everywhere on the territory of zasek; Deminka, Leninsky district, 3.V–26.V 2014); 7. Rh. ferrugineus (Paykull, 1800) (places of finds: Severo-Vatsevo forestry, Odoevsky district, 27.V 2006; Petrovskoye, Odoevsky district, 27.V-23.VI 2007); 8. Rh. nitidulus (Fabricius, 1798) (places of finds: Tula, suburban area; Kosaya Gora, Leninsky district; Yasnaya Polyana, Yubileyny, Shchekinsky district); 9. Rh. perforatus (Erichson, 1845) (places of finds: Yasnaya Polyana, Shchekinsky district; Severo-Odoevskoe forestry, Odoevsky district, 7.V–27.V 2012; Deminka, Leninsky district, 26.V–1.VII 2014); 10. Rh. picipes (Olivier, 1790) (places of finds: Severo-Vatsevskoe forestry, Odoevsky district, 22.V–5.VII 2006); 11. Rh. puncticollis (C. R. Sahlberg, 1837) (places of finds: Severo-Vatsevskoe forestry, Odoevsky district, 22.V-3.VI 2006; Severo-Vatsevo forestry, Suvorovsky district, 1.V-3.VI 2007; Supruty, Shchekinsky district, 13.V-10.VI 2007). Subfamily Monotominae Laporte, 1840: 12. Monotoma angusticollis (Gyllenhal, 1827) (places of finds: Severo-Odoevskoe forestry, Odoevsky district, 27.V-16.VI 2012); 13. M. brevicollis Aubé, 1837 (places of finds: Yasnaya Polyana, Yubileyny, Krivtsovo, Shchekinsky district); 14. M. longicollis (Gyllenhal, 1827). (places of finds: Monastyrshchino, Kimovsky district, 24.VII 2007; Staroselye, Belevsky district, 7.VIII 2010; Varushitsy, Suvorovsky district, 14.VII–31.VII 2014); 15. M. picipes Herbst, 1793 (places of finds: Griboyedov, Kurkinsky district, 19.VIII 2006; Malaya Salnitsa, Chernsky district, 24.VII 2010; Samokhvalovka, 30.V 2013; Varushitsy, Suvorovsky district, 1.VI–31.VIII 2014; ibid., 1.X–1.XI 2014).
Distribution of the four-eyed fir bark beetle (Polygraphus proximus Blandford) in forest stands of the Sverdlovsk region
The fir four-eyed bark beetle (Polygraphus proximus Blandford, 1894) (Coleoptera, Curculionidae: Scolytinae) was unknown in the Sverdlovsk Region till 2023. The portion of Siberian fir in the forest stands in the Sverdlovsk region is insignificant, the area occupied by fir is about 175 thousand hectares or 1.4 % of the area of the main forest-forming species of the region (2.4 % of the coniferous area). The main part of fir stands is concentrated in the western part of the region where the main specially protected natural territories of the region are located: the Visimsky Nature Reserve, the «Denezhkin Kamen» Nature Reserve, the Natural Park «Olenyi Ruchyi» and the Natural Park «Reka Chusovaya». The purpose of the study is to identify the spreading of bark beetle the Sverdlovsk region, to assess the plant damage and the rate of development of foci in areas with high density of this species. As a result of examination conducted during 2023–2024, the bark beetle was found in a significant area of fir stands in the western part of the Sverdlovsk region. In the north of the region, damage to plantings by invaders has been found up to the city of Serov (59° 35' N). In the northern regions, the species density is currently relatively low. Significant foci of outbreak are forming in the southwestern part of the region. The Rosselkhoznadzor has currently established three quarantine zones in this area with a total area of 10,655 hectares. An analysis of the rate of development of foci of outbreak in the «Olenyi Ruchyi» Nature Park showed that in some areas by the autumn of 2024, up to 50 % of the trees had either already dieback or were inhabited by the invader. It is not clear yet how far the bark beetle will spread to the north of the region. To predict the possible limits of the range expansion (primarily the northern ones), it is necessary to clarify the phenological characteristics of this species in the Sverdlovsk region.
Expansion of the range of the ash borer (Agrilus planipennis Fairmaire, 1888) in the south-east of the European part of Russia
The emerald ash borer (Agrilus planipennis) is a dangerous pest of ash trees (Fraxinus spp.) in the northern hemisphere. The data are presented on the current distribution of A. planipennis on the southeastern border of the invasive range in the European part of Russia. From 2021 to 2024 route surveys of plantings and forest stands were carried out with the participation of F. excelsior and F. pennsylvanica on the territory of the Tambov, Penza, Voronezh, Saratov and Volgograd regions. At the end of 2024, the distribution covered the whole Voronezh region, a significant part of the east of the Tambov region, the western and central parts of the Saratov region, the northwestern part of the Volgograd region, the Bekovo and Serdobsk districts of the Penza region and the city of Penza. Both the gradual spread of the pest and the formation of enclaves outside the main territory of the invasive range are observed. The rapid spread of A. planipennis and the formation of isolated foci of mass reproduction are associated with unintentional dispersal by humans via road and rail transport. The primary targets of pest attack are ash forests near roads and railways, railway junctions and stations, and automobile terminals. A. planipennis colonizes both ash species growing in the area, with a clear preference for F. pennsylvanica. The successful advancement of the pest is facilitated by the widespread use of ash trees in forestry and landscaping. Natural forests with F. excelsior located inside the territories of mass reproduction began to be noticeably affected by the pest only in 2023–2024. That was several years after the dieback of F. pennsylvanica stands. Active penetration of the pest into the territory of the Nature Reserve «Khopersky» and the Reserve «Ramonye» (the Voronezh Region) is noted.
Features of the biology of the horse chestnut leafminer Cameraria ohridella Deschka et Dimić, 1986 (Lepidoptera: Gracillariidae) in the Donbass
In the process of studying the biology of the horse-chestnut leafminer Cameraria ohridella Deschka et Dimić, 1986 (Lepidoptera: Gracillariidae) in 2020 in the Donbass, the development of the species in three generations was recorded. The fourth facultative generation, observed at the initial stages of invasion, disappeared in the process of adaptation of the species to local climatic conditions. As an adaptive element, the species has developed a mechanism of prolonged preparation for wintering, which is expressed in the departure of some pupae into diapause already in the first and second generations. The number of pupae leaving for wintering in summer generations did not depend on the population density of the leaf blade. Cleaning fallen leaves in the autumn was not an effective method to reduce the number of leafminer. Intensive watering of trees contributes to the preservation of a larger area of green mass and as a result an increase in the number of moths in the second half of the growing season. The main lethal factors limiting the number of leafminer were the weather conditions in winter, leading to the mass death of hibernating larvae and the impact of parasitoids. The mortality rate in the overwintering generation was 84.5 %, whereas the mortality rates in the first and second generations were 31 % and 21 %, respectively. The parasitoid complex was represented by 8 species of ecto- and endoparasitic Hymenoptera from the family Eulophidae. Two species dominated in frequency of occurrence: Pediobius saulius and Minotetrastichus frontalis. The maximum level of parasitic infestation fell on the first generation of leafminer and amounted to 30 %. The total parasitic load resulted in the death of 24 % of larvae and pupae, which shows a significant role of parasites in the regulation of leafminer abundance.
Phenology and morphometric characteristics of the stellate sawfly in the Bryansk region
Breeding centers of the star-tailed sawfly, Acantholyda posticalis, are expanding rapidly in the Bryansk region. From 2009 to 2024, the area of its foci increased 47 times. In Russia, A. posticalis is one of the widespread pests of pine stands. Its phenology and morphometric characteristics have distinctive features in different regions. The object of the study is the populations of A. posticalis in the pine plantations of the Bryansk Forestry State Institution. The observations were carried out on 64 test areas located in the breeding ground of the sawfly. The phenology of pest development was studied by periodically determining and accounting for the phases of development with a frequency of 5–10 days over two years (autumn 2023 – spring 2025). In total, 193 reference soil pits were laid and the parameters of more than 600 larvae were taken into account. In the territory of the Bryansk region, flight of insects begins in late April – early May, and the largest – in the second decade of May – June. The flight begins with an average daily air temperature above 13.3 °C. Egg laying takes place from May to June, eggs are laid for 2–3 weeks. Flight of A. posticalis starts much earlier in the Bryansk Region than in other regions. Larvae appear from the 1st week of May to July. In the Bryansk region, 99.8 % of wintering individuals are yellow. The pupal phase lasts 8–15 days. Generation is annual, and part of the population always goes into diapause. In the course of the work, a diagram of the annual development cycle of A. posticalis was drawn up in the conditions of the Bryansk region. The parameters of A. posticalis larvae recorded in the Bryansk region differ from previously published data for other regions. The average weight of females is 0.12 g, males – 0.06 g; the average length of females is 16.7 mm, males – 13.7 mm; the average width of the head capsule of females is 2.04 mm, males – 1.84 mm. This indicates the regional peculiarities of the larval body parameters
The formation of invasive areas by alien phytophages revealed in the south of Russia in 2020–2023
The south of the European part of Russia and the regions bordering are attractive to alien insect due to its warm climate and diverse vegetation. The research was focused on the insect pests identified in the region in 2020–2023, namely: Stephanitis pyrioides (Scott, 1874) (Hemiptera: Heteroptera: Tingidae), Pochazia shantungensis (Chou et Lu, 1977) (Hemiptera: Auchenorrhyncha: Ricaniidae), Haritalodes derogata (Fabricius, 1775) (Lepidoptera: Crambidae), Coptodisca lucifluella (Clemens, 1860) (Lepidoptera: Heliozelidae) and Xylosandrus compactus (Eichhoff, 1876) (Coleoptera: Curculionidae, Scolytinae). The research was conducted using a route method on the territory of the subjects of the southern European part of Russia: Krasnodar and Stavropol Regions, the Republics of Crimea, Adygea, as well as on the territory of the neighboring Republic of Abkhazia during the 2020–2024 growing seasons. It was concluded that by the end of 2024 the invasive range of S. pyrioides in Russia occupies the entire territory of Sochi and has disjunctions in Gelendzhik (Krasnodar Territory), and in Abkhazia it occurs in Gulrypsh, Sukhum and Gal district; colonies of P. shantungensis are present only within city Sochi and Federal Territory Sirius (Krasnodar Territory); H. derogata is actively expanding its invasive range in Russia (Krasnodar Region, Republics of Crimea, Adygea) and in Abkhazia; C. lucifluella is present in three regions in the south of the European part of Russia (Krasnodar Region, Stavropol Region and the Republic of Crimea) and throughout Abkhazia; X. compactus is found in two regions in the south of the European part of Russia (Krasnodar Region and the Republic of Crimea) and in Abkhazia. The distribution of species within the invasive areas in southern Russia occurs with planting material (S. pyrioides, X. compactus), with traffic flows (P. shantungensis, H. derogata, C. lucifluella), tourists' luggage (P. shantungensis), independent flights (long–distance – H. derogata, inside park plantings – P. shantungensis, X. compactus).
Features of the effect of the saproxylic insect complex in the process of mycogenic xylolysis of dead wood and woodpiles from spruce and pine
The process of wood xylolysis is especially important at the sites of sanitary and health measures. We believe that the utilization of felling residues, dead wood, and woodpiles by nature-like methods is largely related to the activity of associative organisms – xylotrophic macromycetes and invertebrates. The studies were conducted in 2015–2024 in illiquid wood harvesting sites on 1,270 model woodpiles and 332 model trees of European spruce and Scots pine. Total of 5,166 wood samples and 4,479 saproxylus individuals were studied. The functional effect of a number of families of saproxylic insects is to accelerate the mechanical destruction of wood. In the course of research, it was found that in the early stages representatives of the subfamily Scolytinae, the family Buprestidae and the genus Pissodes dominate, then insects from the families Siricidae and Cerambycidae join them. The re-moistened wood is used by representatives of the Anobiidae and Cerambycidae families of the Hylotrupini and Callidiini tribes. As a result, it was possible to identify the indicator species of saproxylic insects by the preservation of larval galleries by stages of xylolysis. The preservation of larval galleries in stages IV-VI depends on the intensity of rot development and the position of the trunk and is identified by preserved fragments and flight holes. Mathematical analysis data showed a significant direct relationship between trunk perforation by larval galleries of saproxylic insects of the genus Anthaxia, Phaenops, Acanthocinus, Callidium, Rhagium, Tetropium, Trypodendron and mycelium growth of xylotrophic macromycetes of the genus Fomitopsis, Rhodofomes, Trichaptum, Gloeophyllum (r = 0.7–0.96, P ≤ 0.05), as well as between Trypodendron, Anobium, Chalcophora, Tetropium, Arhopalus, Hylotrupes, Monochamus, Spondylis, Sirex, Urocerus and Coniophora, Neoantrodia, Pycnoporellus, Skeletocutis, Antrodia, Fuscopostia, Incrustoporia, Rigidoporus (r = 0.7–0.99, P ≤ 0.05). Our long-term data confirm the interaction of the type of zoochory between insects and fungi in the process of destruction of coniferous wood at the site of their death. Under the changed conditions, no saproxylic insect settlement was detected on the woodpiles. The results obtained are of great practical importance for the nature-like controlled and directed development of wood humification processes at sites of sanitary and health measures, while preserving biodiversity in detritus (decomposition chains) food chains and increasing the stability of natural ecosystems.
Bark-beetles and wood borer pests of forests in specially protected natural areas of St. Petersburg and the possibilities of controlling their numbers
The results of observations of the populations of dominant pests in forest ecosystems of specially protected natural areas (SPNA) of St. Petersburg are presented. The forest pathology survey was conducted in 2022 on 276.6 hectares in accordance with the approved procedure for conducting forest pathology surveys and the form of the forest pathology survey report. The greatest danger is posed by bark-beetles and wood borer pests and, in particular, the European spruce bark beetle Ips typographus. When calculating by the stock in forest pathology sections, its occurrence varied from 44 % to 95 %. In the case of assessing the occurrence in stands of different ages when calculating by the occurrence of inhabited trees from the total number of trees, the differences can be significant. Microfoci and species composition of pests were identified during route surveys. The dynamics of the European spruce bark beetle population was established during the analysis of model trees and the use of pheromone traps. Analysis of model trees in 2022 and 2023 and capture with pheromone traps showed that the outbreak of the bark beetle, which captured the spruce forests of the open-air natural territory of St. Petersburg, began in 2021 and ended in 2023. In the period from 2022 to 2024, the number of beetles caught with pheromone traps decreased annually by an order of magnitude. In 2024, the number of bark beetles corresponded to the background one. The main role in the attenuation of the outbreak was played by entomophages, primarily non-specific predators Thanasimus femoralis and Th. formicarius. Their reproduction led to a decrease in the number of pine beetles. Regulation of the number of pests in the open-air natural territory is hampered by the current regulatory framework for forest protection measures in the forest fund. Ash plantations of Dudergof Heights continue to degrade, where, in the foci of Halar necrosis, a high number of ash beetles has been noted. In these plantations, there is a high probability of appearances and reproduction of the emerald ash borer Agrilus planipennis.
Modification of flight-interception trap construction for catching dendrophilic insects
Traps for collecting entomological material are used in ecological, taxonomic and genetic studies of insects, as well as for monitoring the number of insects in plantations or agricultural lands, warehouses of forestry and agricultural products. To catch saproxylic insects without the presence of a collector, barrier-funnel modifications of flight-interception traps are used, the principle of which is based on creating an obstacle in the path of the insect, which, hitting the barrier, gets into the storage tank. Despite the simplicity of the design, various factory modifications have a number of disadvantages that limit their use. Important parameters of the barrier-funnel trap are the size and weight of the structure, the area of the working surface of the trap, as well as the diameter of the storage tank. The suggested modification offers trap strength increased by upper cross frame and lower metal ring. The differing trap plates format (A3 and A4) allows the trap to be used at different heights from the ground and in tree canopies. All these aspects of the trap design were taken into account by researcher Alexander Petrov, who has been collecting various bark beetles for over 30 years. The publication provides an original diagram and description of the design of the Petrov barrier-funnel trap, which from year to year shows maximum efficiency in collecting entomological material in various types of forest cenoses. At the same time, it has components available for use and is compact for transportation when folded, and bringing the trap into working position takes several minutes. The described modification of the trap can be used together with a light source to catch insects with positive phototaxis, as well as with the use of species-specific pheromone dispensers for selectively attracting individual species of insect pests in forest plantations.
Submersion as a tactic to destroy beetles of four-eyed fir bark beetle in the bark of fir logs
The laboratory experiment was used to determine the time of fir log submersion necessary for complete mortality of the beetles of the four-eyed fir bark beetle Polygraphus proximus Blandf. (Coleoptera: Curculionidae: Scolytinae), a Far Eastern invader. Simultaneously, the fate of a complex of Polygraphus parasitoids: two species of parasitic chalcids Dinotiscus eupterus Walker and Raptrocerus mirus Walker (Hymenoptera: Pteromalidae) – was traced in the processed cuts. At room temperature, 100% mortality of four-eyed fir bark beetle occurred after 3 weeks of submersion and of parasitoids after 4 weeks. In natural conditions, in spring, the submersion time should be increased, because at low temperatures the metabolism of insects may be reduced and their death in anaerobic conditions will occur later. We recommend keeping infested logs under water for at least 6 weeks in spring.
Infectious diseases of branches, bark and wood of horse chestnuts (Aesculus L.) in urban plantings of Sochi
Long-term studies of the vital state of horse chestnuts (Aesculus L.) in urban plantations of Sochi have revealed their not-well condition in Sochi urban plantatings – the prevalence of weakened (74.7 %), severely weakened (11.6 %) and dying trees (5.3 %) in all urban planting types and a relatively small percentage of healthy trees (7 %). The main reason for the deterioration of the vital condition of horse chestnuts were infectious diseases of wood, bark and branches caused by 19 species of phytopathogenic organisms. The pathovar of the phytopathogenic bacterium Pseudomonas syringae pv. aesculi was first discovered in Sochi. It caused bacterial bleeding cancer disease, leading to localized death of the cambium and the formation of perennial bark wounds and cracks, often deep crevices in the trunk. The decisive factor in the gradual weakening and death of adult horse chestnut trees were xylotrophic fungi (16 species) – causative agents of stem, butt and wound rot, among which the most significant in terms of occurrence and harmfulness the causative agents of stem rot – Cerioporus squamosus and Spongipellis spumea – and associated fungal species – Flammulima velutipes and Volvariella bombycina, as well as the causal agents of butt rot – Ganoderma applanatum and G. lucidum – and wound rot – Chondrostereum purpureum, Cerrena uncolor, Schizophyllum commune and Stereum hirsutum – should be recognized. Deterioration of the vital state of horse chestnuts in the row "park plan-tings – intra-block plantings – plantings on the embankment of the river Sochi – street plantings" was mainly due to the increase in the proportion of weakened, severely weakened and dying trees affected by various stem and butt rots and bacterial bleeding cancer disease. The three main types of infection gates for the infecting of horse chestnut wood with xylotrophic fungi were unhealed cuts on the trunk and skeletal branches, deep cracks in the bark and crevices in the trunk (a consequence of damage by bacterial bleeding cancer disease) and deep wounds to the trunk and butt caused by construction equipment and vehicles.
Forest and meadow groups of common oak ecotypes and their phytopathological characterization
The purpose of the work – to analyze the macromorphological parameters of the crown characteristic of the forest and meadow groups of Quercus robur ecotypes and to provide a comparative phytopathological description of these two groups. A comprehensive study of the crown parameters of 28 Q. robur trees and the phytopathological state of the corresponding trees was carried out. We selected 14 specimens of subsenile age (VI< age class), currently confined to open spaces. The crown width was considered as a characteristic feature of this group of ecotypes, the quantitative assessment of which is the ratio of the tree height to the maximum crown width. For comparison, we also randomly selected 14 subsenile trees (VI< age class) from the studied array of forest oak ecotypes and their crown was characterized by the same parameter. The rank analysis of variance according to the Kruskal – Wallis criterion showed a statistically significant difference between the two samples: at the level of p ≤ 0.00001 at p < 0.05 the trees of the meadow and forest groups of common oak ecotypes statistically significantly differ in the condition category. To identify the correlation between the trunk diameters of trees of the meadow and forest groups of Q. robur ecotypes with the condition category and crown lesions by Colpoma quercinum and Vuilleminia comedens, rank correlation analysis was performed according to the Spearman criterion, which showed the following: 1) for trees of the meadow group of Quercus robur ecotypes, a statistically significant relationship was found between the rank of tree diameter and the condition category Rs = 0.73 at p < 0.05; for trees of the forest group of common oak ecotypes, no reliable relationship was found (correlation is not traced), Rs = –0.28; 2) for trees of the meadow group of Q. robur ecotypes, a moderate correlation was found between the crown damage by Colpoma quercinum and the trunk diameter rank, but it was statistically insignificant, Rs = 0.24; 3) for trees of the forest group of pedunculate oak ecotypes, there was no correlation between the crown damage by C. quercinum and the trunk diameter rank, Rs = –0.20; 4) for trees of the meadow group of Q. uercus robur ecotypes, a weak correlation was found between the crown damage by Vuilleminia comedens and the tree diameter rank, but it was statistically insignificant, Rs = 0.10; 5) for trees of the forest group of Quercus robur ecotypes, there was no correlation between the crown damage by Vuilleminia comedens and the tree diameter rank, Rs = –0.26. Thus, it was shown that the phytopathological condition of trees of the two compared groups of ecotypes is significantly affected not by the local hydrological conditions of the habitat, expressed in the thickness of the trunk, but by the value of the crown projection, expressed through the crown coefficient.
Phytopathological monitoring of plantings in the park of Saint Petersburg State Forest Technical University
In order to identify threatened trees, major diseases and damage to tree species in the park of the St. Petersburg State Forestry University named after S.M. Kirov, which is under the protection of the Committee for State Control, Use and Protection of Historical and Cultural Monuments (KGIOP), a phytopathological examination was performed using existing techniques. The park is dominated by old trees. As trees grow and develop, profound changes in the structure of the wood occur. Trunks are often affected by rot caused by various types of wood-destroying fungi. Clumpy and central rot are especially dangerous, causing a decrease in the mechanical strength of trunks, well as root rot that disrupts supporting functions. As a result of the survey, the condition of the trees was determined, fungal diseases and their foci were identified, damage to trees as infection gates, and threat trees were identified, most of which show signs of damage by wood-destroying fungi. The largest number of threatened trees is represented by maple Acer platanoides L. (46 %), as well as leaf-crown Larix sp. (14 %), linden Tilia cordata L. (13 %) and oak Quercus robur L. (7.5 %). The main criteria for the allocation of these trees to the "threat" category were the presence of rot, fruit bodies of fungi, hollows, trunk slopes with root tearing – an indirect sign of root rot – or with a slope of 45° or more. Recommendations aimed at increasing safety for material assets and visitors to the park, as well as contributing to the preservation of the park's landscape compositions, are proposed. Trees affected by pathogens that cause stem and root rot are recommended for harvesting.
Spread of wound canker of spruce in the northern taiga forests of the European part of Russia
The patterns of spread of spruce wound canker development including the spatial dynamics of the number and size of wounds on the tree, the proportion of damaged trees and trees with overgrown (or healing) wounds were studied. The data were collected in taiga spruce forests in 2022–2023 in five groups of sample plots located in five remote areas of the Leningrad Region, the Republic of Karelia and the Murmansk Region (N59°–67°). It was found that in the study area, spruce canker, despite its widespread distribution and high occurrence, does not lead to a critical deterioration in the condition of tree stands. The differences between the groups of deadwood condition categories (5,6) in the number of observed ulcers are statistically insignificant. There is a trend of decreasing ulcer sizes from south to north, which may indicate the influence of climatic factors on the pathogen activity. According to the sizes of canker wounds, single samples differ from the rest between the groups of samples by stand density and age category, but there are no consistently directed differences. For example, the sizes of canker wounds do not have reliable differences between most categories of forest types, however, in wet blueberry forests, the registered wounds are statistically smaller than in fresh blueberry forests. Such differences may indicate the presence of unaccounted factors or the specificity of the sample. For further study of the factors of formation, development and spatial-typological spread of wounded canker, it is necessary to modify the methodology for accounting for pathogen manifestations due to the presumed influence of other environmental factors not taken into account in this work.
Impact of the weather and climate factors of Moscow region on the growth of Scots pine in the provenance trials affected by annosum root rot
Geographic provenance trials are valuable objects for predicting the effects of climate change on the condition of forest stands. It is especially important to study their response to such damage factors as drought and temperature rise. The work was carried out in 2023 in Scots pine provenance trials in the Serebryanoborskoe experimental forestry of the Institute of Forest Science of the Russian Academy of Sciences (located west of Moscow; aged 73–75 years). These pine plantations are affected by annosum root rot (Heterobasidion annosum (Fr.) Bref.), and the degree of damage to different climatypes is different. Based on the results of the study of dendrochronological samples for all climatypes, a reliable correlation was established between the radial growth indices and three meteorological parameters: the amount of precipitation during the growing season, the amount of precipitation in July, and the moisture supply of the growing season. The growth rate is largely influenced by moisture availabi-lity during the growing season: pines identically reduce radial growth when drought conditions set in. A moderate correlation was found between the moisture supply of the growing season and the growth index value: for different climatypes, the correlation coefficient with a significance level of 0.01 ranges from 0.37 (Brest region, Belarus) to 0.51 (Altai region, Russia). No significant relationship was found between the average annual air temperature and the growth indices. The influence of weather and climate factors on the growth rate is most noticeable in climatypes from Buryatia and the Altai region, which are affected by annosum root rot to a greater extent than the other examined climatypes. The largest number of reliable values of the correlation coefficients was found for them. This indicates their comparatively high meteorological sensitivity. A more noticeable response of growth to drought was in climatypes with a relatively high level of damage by annosum root rot (Buryatia and the Altai region). Most likely the weakening of trees caused by a deficit of precipitation was the reason for the susceptibility of these climatypes to the disease.
Influence of the soil moisture on the formation of foci of root rot of woody species in the stands of Elagin Island
The main pathogens causing rot of growing trees, their prevalence and influence on the condition of the island's plantations have been identified. Significant damage to the plantations is caused by the agaric honey (Agaricomycetes Doweld), which is the cause of weakening, tree desiccation, windthrow and deadwood. The most widespread are: Armillaria gallica – 45 %; Armillaria cepistipes – 19 %; Desarmillaria tabescens – 16 %; Flammulina velutipes and Kuehneromyces mutabilis – 14 % and 6 %, respectively. The percentage of agaric honey cover in the park ranges from 0.4 % – Kuehneromyces mutabilis – to 4.0 % – Armillaria gallica. Phytopathological condition of plantations is assessed as weakened, the average category for all species is 2.45 points. In order to identify the influence of soil moisture on the formation of root rot foci on the territory of Yelagin Island, the study of soil water regime and phytopathological survey was carried out. Water regime of mineral soils of the island has a number of peculiarities: in May and September groundwater level is close to the surface, in June–August it decreases. The drainage norm necessary for growth and development of trees is not provided in all sections, the probability of flooding of the root-inhabited layer of soil on them was 8 %–32 %, only in some sections the groundwater availability is 0% (no flooding of tree roots was observed). There is a double inflow of groundwater into the soil, capillary-suspended moisture from above and capillary-suspended moisture from below. The groundwater filtration coefficient of the upper soil layer is 1.63 m/day and that of the lower layer is 105.71 m/day, which leads to moisture stagnation. A map of waterlogging of tree roots was drawn up based on measurements of soil-soil water levels. Water stagnation and soil overwatering negatively affect the condition of plantations and favour the development of root rot. The probability of pathogen development increases with increasing soil moisture. A map of pathogen foci has been drawn up.
Primary data from phytotests on seedlings: specificity of nematodes of the genus Bursaphelenchus to different host plants
The specificity of three species of nematodes of the genus Bursaphelenchus: B. willibaldi (Fungivorus), B. ulmophilus (Hoffmanni), B. michalskii (Eggersi) to three species of woody plants: Picea abies, Acer platanoides, Fraxinus excelsior was tested in laboratory conditions. The test was aimed at identifying the vector-independent specificity of nematodes to host plants. The experiment was conducted on indoor seedlings under laboratory conditions. Nematode isolates were stored in the live culture bank of the Zoological Institute of the Russian Academy of Sciences. The worms were cultured in a sterile culture of the fungus Botrytis cinerea before the test was set up. As an inoculum for infecting the seedlings, 200 individuals of the same species of nematodes at different developmental stages were used per plant. The experiment was conducted at 21–23 °C for 45 days. The parameter for successful reproduction is the excess of the final nematode population over the inoculum. The species B. willibaldi demonstrated survival on all three experimental plant species, but no excess of nematodes compared to the inoculum was recorded. B. ulmophilus survived on P. abies and A. platanoides. B. ulmophilus was not detected on F. excelsior. B. michalskii was not detected in any of the infested plants 45 days after inoculation. This indicates that this nematode species is not able to survive on the plant species represented. The probability of vector-independent specificity of the three submitted nematode species to the tested range of plants is low.
Features of soil microbiomes restoration of forest phytocenoses after fires in the steppe and forest-steppe zones of Central Siberia
Studies were conducted in forest phytocenoses of the steppe zone of the Shirinsky district (Khakassia Republic) and the forest-steppe zone of the Pogorelsky pine forest (Krasnoyarsk region) damaged by fire. Using microbiological indicators (quantitative and qualitative composition of microorganisms, microbial biomass content, microbial respiration, enzymatic activity), the rate of restoration of biological activity of soils in artificial plantings of forest plantations of Scots pine, Siberian larch, Siberian elm and in a pine forest of a natural forest was assessed. It was found that after fires, the biological activity of the studied soils is restored faster in postfire sites (not completely burnt tree stand) than in burnt areas (completely burnt tree stand) due to the large amount of pyrogenic carbon (Cpyr) and pyrolysis/pyrogenesis products and significant combustion of the soil cover. It is noted that for different types of the studied soils (agrozems and dark gray), an adequate assessment of their condition is provided by universal indicators (total number of microorganisms, content and specific respiration of microbial biomass, enzymatic activity), which reflect the biological activity of soils and indicate the direction of restoration processes. In agrozems under forest plantations of the Shirinskaya steppe, specific indicators were dominant bacteria of the order Actinomycetales and fungi of the genera Mortierella Coem and Penicillium Link. In the dark gray soil of the pine forest of the Pogorelsky pine forest after the fire, non-spore bacteria (Serratia plymuthica) dominated, spore bacilli (Bacillus mycoides) were sodominants, as well as fungi of the genera Trichoderma Pers. and Umbelopsis Amos & H.L. Barnett.