Gnathotrichus materiarius Fitch, 1858 is a North American ambrosia beetle that has progressively expanded its distribution across Europe during the twentieth and twenty-first centuries. The aim of this study was to assess its occurrence in Slovakia based on multi-year surveys conducted in the Záhorie region and to document its first national record. Monitoring was carried out in 2021 and 2025 in pine-dominated stands using traps baited with pheromone and kairomone attractants. No individuals were detected in 2021. In 2025, two adults of G. materiarius were captured at a single site during the first inspection of traps baited with a (+)-α-pinene and ethanol blend. A large volume of stored pine timber was present in close proximity to the capture site, providing suitable breeding material. The findings suggest a recent introduction or early stage of establishment in Slovakia. Although the species is regarded as a technical pest of coniferous wood, it does not colonize healthy trees and currently poses a limited risk to vital forest stands. Continued targeted monitoring is important to assess its further spread.

Introduction European elms (Ulmus minor, U. laevis and U. glabra) are strongly constrained by biotic stress, and increasing summer drought may further limit their performance under climate change. Here, we investigated drought-driven changes in the primary and secondary metabolism of leaves in the three native European elm species grown under semi-field conditions and two watering regimes.Methods Leaves of the three elm species were analyzed using untargeted LC-MS and GC-MS metabolomic profiling. The analyses were complemented by quantification of non-structural carbohydrates and major phenolic classes, including total phenolics, flavonoids, and condensed tannins. The study evaluated the effects of sampling date, tree species, and watering regime on metabolite composition to determine the relative influence of drought and temporal dynamics.Results and discussion The metabolomic analyses revealed pronounced species-specific differences in both non-volatile and volatile metabolite profiles. GC-MS data were dominated by typical green-leaf volatiles (e.g., (E)-2-hexenal and (Z)-3-hexenyl acetate) and terpenes, which were generally more pronounced in U. glabra and U. laevis than in U. minor. Overall, species identity and sampling date explained a substantial proportion of the metabolic variation, while drought effects were moderate but species-specific: multivariate metabolomic separation was strongest in U. glabra, whereas U. laevis showed the clearest drought-associated increase in total phenolics, flavonoids and condensed tannins, and U. minor remained the most stable. These results indicate contrasting drought-response strategies among European elms; however, stronger metabolic responses do not necessarily reflect higher drought tolerance. Rather, U. minor appears to maintain greater metabolic stability under drought, whereas the pronounced changes observed in U. laevis likely reflect higher sensitivity to water deficit. Furthermore, the strong effect of sampling date highlights the importance of temporal dynamics in shaping plant responses to drought.

Bark beetles and pinhole borers of Georgia and Kyrgyzstan were surveyed between 2003 to 2025. Specimens were collected using pheromone traps baited with Acuwit, IAC Ecolure, Sexowit, Tomowit, and ethanol; 0.5-m-long logs exposed for bark beetle colonisation; direct hand collecting in the field; searches for potential feeding substrates; and rearing from infested host material. We present 51 faunistic records of bark beetles and pinhole borers, comprising 44 species from Georgia and seven from Kyrgyzstan. One taxon is newly recorded from Georgia: Pityophthoruspityographus cribratus. Finally, we provide complete checklists of bark beetles and pinhole borers recorded from Georgia (98 species) and Kyrgyzstan (34 species).

Understanding the structure and allocation of belowground biomass is essential for improving assessments of tree stability, biomass accumulation, and responses to environmental conditions. This study investigated biomass partitioning, root architecture, and allometric relationships of Norway spruce (Picea abies L. Karst) using data from 100 trees sampled across ten sites in Central Europe, namely the Czech Republic and Slovakia. Stem and aboveground dimensions were measured, and root systems were excavated. The roots were then classified according to depth, and the volumes of stems, stumps, and roots were quantified. Allometric models based on tree height (H), diameter at 0.2 m (D0.2), and diameter at breast height (D1.3) were used to predict component volumes separately for stems, aboveground stumps, belowground stumps, and roots. Root distribution showed pronounced site-dependent variability. On average, 76.4% of root volume was concentrated within the upper 30 cm of soil, 16.7% occurred between 31 and 60 cm, and only 6.9% extended below 60 cm. Shallow rooting might be associated with waterlogged pseudogley soils and compact podzols. Stems represented the largest proportion of total volume of studied tree parts (77.9%), followed by roots (15.1%), belowground stumps (4.1%), and aboveground stumps (2.9%). Root contribution ranged from 10.4% to 24.0%. Allometric analyses demonstrated that D1.3 was the most reliable predictor of tree component volumes, outperforming H and D0.2 in most cases. Stem volume and total volume of studied tree parts were predicted with the highest accuracy, whereas belowground stump volume showed the greatest variability. These results highlight the importance of incorporating site-specific rooting characteristics into forest inventories and management practices, particularly in the context of increasing risks of drought and wind disturbance associated with climate change.

BACKGROUND:The bark beetle Taphrorychus bicolor has been traditionally classified as a secondary pest of European beech. However, climate-induced stress and increased host availability may enhance its importance in forest ecosystems. Despite the high abundance of this pest, data on its reproductive biology and colonisation preferences remain limited. Therefore, we conducted three experiments, each addressing a different aspect of T. bicolor ecology (colonisation density, population-substrate relationships, and reproductive success), to assess its colonisation behaviour on beech logs and logging residues at selected Central European sites. RESULTS:In the first experiment, both trap catches and entry hole densities declined between years, but no significant relationship between trap catches and colonisation density was detected after accounting for year effects. In the second experiment, reproductive success was quantified by comparing the numbers of entry and exit holes and emerged adults from colonised logging residues. Exit holes were moderately correlated with beetle emergence, whereas entry holes showed weaker predictive power. This pattern may reflect mortality or re-entry behaviour. In the third experiment, T. bicolor was the dominant coloniser across five study sites, whereas ambrosia beetles were sporadic, suggesting limited interspecific competition under the conditions studied. Colonisation density was significantly reduced under full sun exposure but unaffected by pheromone- and kairomone-based lures or log dimensions. CONCLUSIONS:T. bicolor showed consistent reproductive success on small-diameter beech logging residues with limited interspecific competition. Exit holes provide a reliable proxy for emergence, supporting logging residue management. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

In the last few decades, bark beetle outbreaks have increased in European forests, triggered by extreme weather events, such as drought and windstorms. A core element of integrated pest management to control outbreaks are salvage logging and sanitation felling, i.e., the timely removal or treatment of potential brood material and already infested trees after disturbance events. Associated with these management operations as well as with regular, planned thinning and cutting, felling residues, such as treetops, branches and stumps that remain in the forest provide potentially suitable breeding material for bark beetles and may trigger further outbreak events. Although felling residue management is part of regular forest management in most of Europe, no overview exists on its use throughout the continent. To fill this gap, we gathered forest health experts from 20 European countries and used a questionnaire to provide information on felling residue management in the context of forest protection in managed forests. Relevant legislation in these countries was reviewed for regulations concerning this topic. We found that most countries have felling residue management in their legislation and/or perform it in practice. In 12 of the 20 countries, felling residue management is being applied to manage bark beetles, particularly in areas that have experienced large-scale outbreaks in the last few decades. Felling residues are mainly managed in forests dominated by Norway spruce (Picea abies L. Karst) and pines (Pinus spp.) (in 19 and 17 of the countries, respectively). The most frequently used management methods on a European level were piling or mulching of felling residues. These methods were used in 14 and 16 of the countries, respectively. Besides bark beetle management, use of residues for bioenergy (4 countries) and biodiversity conservation (6 countries) was reported. The diversity of felling residue management practices across Europe may reflect differences in forest policies and climatic gradients that are affecting bark beetle outbreak risks. This overview presents the variety of felling residue management applied across 20 European countries, highlighting the reasons for and implications of its use, as well as further research needs.

Orthoptera species distribution ranges are dynamically shifting because of climate change. This article documents the expansion of the short-winged grasshopper Pezotettix giornae in Western and Central Europe between 1990 and 2024. Published records from Central Europe (Austria, Slovakia, Hungary, and the Czech Republic) are supplemented with data from public databases and targeted field surveys, particularly in southeastern Moravia and the Burda Hills region of southern Slovakia. Whereas P. giornae was previously abundant mainly in the Mediterranean reaching northwards into central Hungary, its range has gradually shifted northward over the past 30 years, now reaching central France, Austria, Slovakia, and the Czech Republic, with single individuals transported to northern France, northern Switzerland, central Germany, and the Netherlands. The increase in abundance and the number of newly recorded localities indicate the dynamic spread of this species despite its inability to fly. This expansion is facilitated by climate warming, the species’ ability to colonize ruderal and successional habitats, and passive dispersal via transportation, particularly along road and railway corridors. The case of P. giornae demonstrates that even brachypterous species with limited dispersal ability can undergo significant range shifts. This trend has important implications for ecological modeling and the prediction of future species distributions and biodiversity conservation strategies in the changing European landscape.

IntroductionClimate change has led to rising atmospheric CO2 levels and temperatures, projected to double CO2 concentrations and increase temperatures by 2–5°C by the end of the 21st century. These environmental changes influence plant primary and secondary metabolism, potentially altering plant-insect interactions. Herbivore performance depends on the nutritional quality of host plants, which may decline with elevated CO2 due to an increased carbon-to-nitrogen (C:N) ratio. To explore these effects, the performance of spongy moth larvae (Lymantria dispar) was assessed on oak (Quercus robur) and spruce (Picea abies) seedlings grown under varying climatic conditions. This approach compares a preferred host with a non-preferred one in the case of L. dispar, providing insight into how host plant selection may be influenced under future climate scenarios. In addition, the nun moth (Lymantria monacha), a conifer-feeding species, was also studied on the experimental spruce seedlings to facilitate a comparison with a specialist herbivore.MethodsThree-year-old oak and spruce seedlings were reared for 1 year under four climate scenarios combining two CO2 levels (ambient: 410 ppm and elevated: 820 ppm) and two temperature regimes (20:15°C and 25:20°C). Seedlings were then processed into leaf powder diets for laboratory bioassays with larvae. Secondary metabolites in the seedlings were analyzed to assess climate-induced changes in tree composition and their effects on herbivores.ResultsElevated CO2 increased the C:N ratio in both tree species, with spruce showing a higher ratio than oak. Higher temperatures led to increased nitrogen content, particularly in oak seedlings. L. dispar performed better on oak despite higher secondary metabolite concentrations, while L. monacha exhibited minimal variation in performance on spruce across climate treatments.ConclusionThe combined effects of elevated CO2 levels and increased temperatures impacted plant quality; however, there were nearly no differences in the performance of Lymantria larvae. Despite the higher concentrations of secondary metabolites in the trees, the larvae were able to thrive effectively, demonstrating their resilience to environmental changes.

The bark beetle Taphrorychus bicolor primarily inhabits Fagus sylvatica forests. Its populations increase after periods of drought. Due to the limited knowledge of factors affecting its abundance, we conducted a large-scale sampling. Beetles were captured using three Theysohn traps lured with bicolorin at 26 study sites in mature homogeneous beech forests distributed throughout the Czech Republic. The traps were checked, and beetles were sampled weekly or biweekly in 2022. Using Generalized Linear Mixed Models (GLMMs), the impact of selected environmental and management variables on the abundance of T. bicolor was analyzed. The species occurs at elevations ranging from 150 m a.s.l. to 1300 m a.s.l. throughout the Czech Republic. This represents its entire host range, e.g., beech, although in the lowest elevations it is also found on other deciduous trees. In 2022, the flight activity lasted from late April to early September, and two generations were recorded, with the filial generation starting to fly in late June. In many study sites, more than 10,000 beetles were captured per trap. The number of females trapped was higher than males, consistent with the species' polygamous strategy, where females move toward increasing concentrations of pheromones. The number of beetles in the traps was influenced by elevation, with the highest abundance observed at around 600 m a.s.l. Abundances were higher in areas with more extensive beech forest complexes. Lower beetle abundances were found in stands where the studied forest bordered with meadows, pastures, or crop fields, indicating the species' reluctance to fly outside the forest habitat. The abundance of the filial generation was higher when there was a larger area of beech forests within a 1000 m radius, suggesting a median dispersal flight distance of approximately 1 km for the filial generation.

The ambrosia beetle Xylosandrus compactus (Eichhoff, 1876), originally from Southeast Asia, was first found in Europe in 2010, specifically in Italy. Since then, X. compactus has rapidly spread across southern Europe, including France, Spain, Greece, Turkey, Malta, Slovenia, Russia, Croatia, and Switzerland, gradually moving northward through lower-elevation areas. In 2023, a single female was found near the village of Kameno in Montenegro. This female was sifted through leaf litter in rocky terrain within a deciduous forest mainly populated by oak and hornbeam trees, located 2.5 km from the international port of Herceg Novi.

Bark beetles feed and breed between the bark and the wood of various tree species. Pityophthorus micrographus (Curculionidae, Scolytinae), a small size Euro-Asian bark beetle species living in branches and twigs of fir and spruce trees, is most likely confused with P. pityographus. This misidentification leads to highly incorrect ecological conclusions dealing with occurrence and spreading in the scientific literature. In order to verify the range ofP. micrographus in Central Europe, faunistic data on the occurrences ofP. micrographus were obtained by compiling the first author's distribution data, literature excerpts and physical specimens of beetles in museum collection. In Central Europe, P. micrographus has been documented in a total of 41 localities in six countries. However, since 2000, the species has only been detected in seven localities in three countries: the Czech Republic, Slovakia, and Hungary. This study revealed thatP. micrographus is a boreal species whose range extends into native boreal forests in northern Poland. Furthermore, we show that the species occurs in southern Poland, the Czech Republic, Austria, Hungary and Slovakia, either in natural spruce forests in the mountains or inversion sites with native or introduced spruce species.

Bark beetle Pityokteines spinidens (Coleoptera: Curculionidae: Scolytinae) is widespread across Europe. We identified this species as a pest of Tsuga canadensis in western Bohemia's Americk & aring; zahrada National Nature Monument Arboretum. This discovery suggests that P. spinidens could infest any conifer within the Abietoideae subfamily. Given its status as a known pest of various Abies species, its potential impact on related conifers warrants further attention.

Nemozoma elongatum (Linnaeus, 1761) shows a positive response to artificially produced lures targeting its two main prey species, Pityogenes chalcographus (Linnaeus, 1761) and Taphrorychus bicolor (Herbst, 1793), with a preference for P. chalcographus. We do not recommend using these lures in traps because they could unintentionally capture N. elongatum. However, these lures could potentially aid in controlling target pests by leveraging allochthonous kairomones to attract predators to areas with higher pest densities. Nemozoma elongatum in Central Europe primarily preys on P. chalcographus and T. bicolor, but it can target nearly 40 species of bark beetles. While it responds well to the aggregation pheromone of P. chalcographus, its response to artificial lures for T. bicolor is unknown. The study aimed to confirm if N. elongatum beetles react in the same way to a lure containing bicolorin and Chalcoprax® and if their response to the prey abundance of P. chalcographus parallels the response observed in T. bicolor. During 2022, three Theysohn® pheromone traps were set with Beech Bark Beetle Lure®, containing bicolorin, and one trap with Chalcoprax® in mature beech stands at 11 study sites across the Czech Republic. To study the dependence of the numbers of N. elongatum captured, GLMMs were used to analyze the following variables: both lures, abundance of prey species, abundance of beech, age of beech, altitude, presence of adjacent non-forest areas (such as a freshly exposed edge of a beech forest), and the distances to the nearest spruce forest and the nearest clear-cut area. N. elongatum prefers P. chalcographus as its primary prey, as indicated by its response to the tested lures. Its abundance is dependent on the presence of T. bicolor and P. chalcographus. N. elongatum is a prey opportunist that responds to bark beetle aggregation pheromones, as confirmed for several species. It is frequently caught in traps with Chalcoprax® and bicolorin, the pheromone of T. bicolor. Although more commonly attracted to Chalcoprax®, indicating a preference for P. chalcographus, N. elongatum may consume other species given its attraction to volatile compounds from host trees.

Bark beetle Pityogenes chalcographus is a common species that can impact coniferous forests throughout Europe, especially Norway spruce. Under typical conditions, standard forestry management practices do not lead to increased population densities or pose significant threats to forest stands. This beetle multiplies after abiotic disturbances like windthrow, drought, or snow damage, leading to localized outbreaks. P. chalcographus poses a significant threat to young spruce stands and infests the upper, thin-barked sections of older trees, often alongside Ips typographus. To effectively manage P. chalcographus, it is necessary to implement both preventive and direct control measures. Integrated pest management strategies emphasize the importance of maintaining cleanliness in logging areas, promptly removing infested trees, and reducing available breeding material, particularly fresh logging debris. Pheromone traps are primarily used to monitor flight activity. Cultural control measures involve carefully managing logging debris. This includes piling branches in shaded areas to reduce breeding opportunities for beetles. Timely logging and thinning operations are also important for reducing population growth by making trees less susceptible to attacks. In smaller areas, pheromone traps can be used to capture and to concentrate emerging beetles effectively. This comprehensive review underscores the importance of enhancing current management practices to address the rising challenges posed by P. chalcographus in spruce forests. A deeper understanding of its ecological interactions and adaptive strategies will be key to developing more effective control measures.

Taphrorychus bicolor (Coleoptera: Curculionidae, Scolytinae) is emerging as a potential threat to European beech (Fagus sylvatica L.) in Central Europe, particularly under recurrent drought and a warming climate. We review its ecology, damage symptoms, monitoring methods, and management strategies, integrating published research with recent observations from Slovakia. Regarded as a secondary pest of dead or dying wood, T. bicolor has also been observed infesting living beech trees, producing characteristic lesions that degrade timber quality and may accelerate tree decline. These injuries marked by sap exudation, blister-like bark, and black fluid-filled lesions occur more frequently in drought-stressed stands, especially along forest edges and south-facing slopes. Monitoring trials demonstrated that pheromone-baited traps and felled beech trap trees effectively attract large numbers of beetles, although outbreak thresholds for this species are not yet defined. We recommend preventive management through timely removal and treatment of logging residues and weakened trees to reduce breeding sites. Biological control options, including the predator Nemozoma elongatum and entomopathogenic fungi such as Beauveria bassiana, show promise but require further study. A critical knowledge gap remains regarding the role of secondary infections in lesion development following beetle infestation. Whether T. bicolor represents a persistent threat or a transient response to climatic stress remains unclear, but proactive monitoring and management are essential to mitigate its impact on beech forests. This review provides an updated basis for forest managers, researchers, and policymakers confronting the challenges posed by T. bicolor.

Castanea sativa is a type of cultivated chestnut tree found in the Czech Republic, growing in both lowland and midland regions. These trees are usually planted individually or in pairs, with over half of the plantings located in urban areas. One-fifth of chestnut trees thrive in parks, while chestnut orchards or forest stands make up only one-tenth of the areas where chestnut trees are located. In the Czech Republic, approximately 30 ha are covered by chestnut trees. Regeneration of chestnut trees occurs in only 6% of the localities due to regular lawn mowing. However, 40% of the surveyed forests showed signs of regeneration, demonstrating the species' ability to regenerate under Central European climate conditions.

Gnathotrichus materiarius Fitch, 1858 is an invasive bark beetle that colonizes conifers and has spread widely in Europe. The beetle was introduced from North America to Western Europe, where it was first detected in France in 1933. In countries of Western and Northern Europe, the first detections were found at ports or airports, which probably served as sources of further spread. Gnathotrichus materiarius spread eastward to the Czech Republic and other countries in Central Europe from Germany and Poland and spread northward from Italy to Slovenia. The presence of wilting spruces, outbreaks dominated by Ips typographus Linnaeus, 1758, and the subsequent transport of timber have probably accelerated the spread of G. materiarius. It is possible that G. materiarius was imported with timber to Austria, the Czech Republic, and Poland. Although G. materiarius has been present in Europe for almost 100 yr, and even though its host trees include Picea and Pinus spp., which are abundant in Central European forests, no significant damage caused by this beetle has been detected or reported. Gnathotrichus materiarius is a typical secondary pest in that it multiplies on decaying trees or trees already infested and killed by other bark beetle species. It has 2 generations a year in Central Europe. The beetles of G. materiarius occur the whole year, but the flight of adults starts in early May and the offspring beetles emerge in mid-July. The adults of F2 generation overwinter in wood. The best method for monitoring and detecting the presence of G. materiarius is the use of ethanol-baited traps.

Global warming plays a major role in the disruption of forest ecosystems by bark beetle outbreaks. Decreasing precipitation and more frequent droughts create the conditions for water stress in trees. The Eurasian spruce bark beetle (Ips typographus L.) is more dangerous for Norway spruce (Picea abies (L.) Karst.) forests in Central Europe under these conditions, because even healthy trees under water stress have a lower probability of survival during massive spruce bark beetle outbreaks. This critical issue highlights the importance of targeted research and intervention strategies in affected regions; hence, this study has a focus on the Horn & iacute; Plana region in Central Europe, which is managed by the Military Forests and Farms of the Czech Republic (VLS). The study presents the results of the drought risk assessment of the operational part of TANABBO II and its validation. TANABBO is a high spatial resolution risk assessment tool for spruce bark beetle infestation in Central European forests, incorporating 30 m spatial resolution and extensive meteorological data, which outperforms existing models in its ability to accurately predict bark beetle activity based on the PHENIPS phenological model. The operational part integrates environmental factors such as global radiation, temperature, precipitation and, in particular, water stress, which is assessed by using a transpiration deficit. The drought risk assessment included the calculation of Drought Indices (DI) and Cumulative Transpiration Deficit Indices (CTDI) on a daily basis, and the estimation of spruce bark beetle swarming time using the PHENIPS model. The risk assessment was validated by comparing it with the number of bark beetles caught in traps and the value of the drought index. Generalised additive models (GAM) were used for validation, with the most effective models incorporating the CTDI. The model with the highest predictive accuracy achieved an adjusted R-squared value of 0.478. The study highlights the critical role of high-resolution environmental data in understanding and managing bark beetle outbreaks, particularly in the context of climate change.

Forest fires significantly disrupt global ecosystems. Many forecasting techniques predict fire activity and allocate prevention resources, but various factors are missing from the assessments, and multi-criteria decision approaches alone are insufficient. This work introduced a novel methodology combining artificial neural networks (ANN) with the analytical hierarchy process (AHP), fuzzy AHP multi-criteria methods, and spatial data to detect potential forest fire vulnerability areas using twenty variables. The results from AHP or fuzzy AHP, were processed using a multilayer perceptron with a backpropagation algorithm. The final ANN model has two objectives: first, to create a forest fire vulnerability with four classes (low, moderate, high, and very high), and second, to classify burned area sizes in regions highly or very highly vulnerable to fire. Evaluation metrics were also applied for validation. The fire model was tested using both literature review data and in situ observations. Comparative analysis showed that the burned area size model performed better than other machine learning methods, achieving an accuracy score of 89%. Meanwhile, the fire vulnerability model scored 82%. The study addresses the problem of prediction and provides an algorithm for classifying fire risk based on historical data in the Czech Republic, offering a master model for future forest management. Therefore, the ANN model, once trained, validated, and tested, does not require resetting and is effective for estimating forest fire vulnerability. Moreover, it produces results quickly, providing rapid insights into complex forest ecosystems, saving time and enhancing understanding for decision-makers.

Phloeosinus aubei is invasive in Central Europe, spreading northward from the Mediterranean region because of climate change. P. aubei has the potential to become a pest of mature, naturally occurring juniper trees (Juniperus communis) in protected areas, as well as junipers, thujas and cypresses in nurseries and urban environments. In 2020 and 2021, we conducted two experiments to compare various lures for trapping P. aubei. In the first experiment, we compared four lures: a-pinene; turpentine; a mixture of cade oil, juniper berry oil and ethanol; and a juniper branch (8-10 cm long, 3-5 cm wide) deployed with ethanol. In the second experiment, we compared Hostowit (R) with a juniper branch (8-10 cm long, 3-5 cm wide) deployed with ethanol. In both experiments, juniper branches deployed with ethanol attracted a greater number of P. aubei beetles compared to the other lures. In total, we captured 1056 individuals belonging to 36 species of Scolytinae. Among the most abundant species, Xyleborinus saxesenii, Xyleborus monographus and Anisandrus dispar were lured by ethanol in combination with other substances or deployed with juniper branches. Xyleborus dryographus showed a positive association with turpentine. Ips typographus was positively associated with a-pinene, while Orthotomicus laricis, Hylastes attenuatus and Gnathotrichus materiarius were positively associated with Hostowit (R) lure.