Monitoring Of Population Dynamics Research Articles

Quantitative Approach for Determining Reproductive Life-History Strategies of Parasitic Plants: A Case Study in Balanophora.

Parasitic plants are a diverse and unique polyphyletic assemblage of flowering plants that survive by obtaining resources via direct vascular connections to a host plant. Ecologically important in their native ecosystems, these typically cryptic plants remain understudied and fundamental knowledge of the biology, ecology, and evolution of most species is lacking. This gap limits our understanding of ecosystems and conservation management. We established a multistep protocol to conduct the first investigation of the reproductive life history of root parasite genus Balanophora, testing the hypotheses of perenniality, cryptic perenniality, and plasticity across five geographically isolated populations in Taiwan. A review of 123 Balanophora publications found contradictory determinations, including no determination (87%), perennial (9%), annual (1%), biennial (1%), or a combination (2%). No primary study investigated the question, and no determination was accompanied by reference. Between 2021 and 2024, we tested a hypothesis of perenniality (109 individuals, 135 patches) and cryptic perenniality (73 host samples), monitored population dynamics (whole population), and potential for endophytic/dormant haustorial tissue (101 roots) across five isolated populations of Balanophora fungosa ssp. fungosa in Taiwan. Our results support semelparous annuality. After reproduction, individuals senesce and die, and the following year's population is recruited from newly germinated individuals which together develop in size and number during a vegetative growth period, undergo reproduction, and then themselves senesce and die. Each cycle is completed within a 12-month period. Synthesis: Our study provides the first quantitative determination of a semelparous annual reproductive life-history strategy for any species of Balanophora. This determination is important in our progress toward better understanding the species-and parasitic plants in general-as well as ecological roles within ecosystems and conservation management. Our study further provides a template for future work to expand life-history strategy determination across cryptic root parasitic plants.

Development of the duplex droplet digital PCR for quantitative monitoring of mixed infections of Meloidogyne incognita and M. enterolobii.

Root-knot nematodes (RKN, Meloidogyne spp.) are economically significant pests that cause immense damage to a wide range of crops. Among them, M. incognita and M. enterolobii are of particular concern, as their high virulence and broad host range. RKN are challenging for detection due to their subterranean lifestyle underground. Also, the mixed infection of nematodes in field crops complicates the need for more accurate diagnostic and quantification technologies. To address this challenge, we developed and optimized a novel duplex droplet digital PCR (ddPCR) method, using primer/probe sets targeting M. incognita and M. enterolobii, to simultaneously identify and quantify both species within a single assay. The innovative ddPCR diagnostic demonstrated excellent performance in terms of sensitivity, precision and reproductivity when quantifying the eggs and soil samples containing juveniles of both species. Moreover, the application of the duplex ddPCR method enables the monitoring of population dynamics of M. incognita and M. enterolobii under competitive environmental conditions. Our results indicated that the reproduction factor of M. incognita possibly inhibited when in mixed populations of M. enterolobii. In this study, we first applied duplex ddPCR technique for differentiating mixed infections of M. incognita and M. enterolobii, offering a valuable tool for species detection and quantification. It enables the monitoring of population dynamics for both species, which is crucial for providing theoretical guidance for the implementation of timely and effective control measures. © 2024 Society of Chemical Industry.

Monitoring of Pseudomonas aeruginosa mutational resistome dynamics using an enrichment panel for direct sequencing of clinical samples

Pseudomonas aeruginosa is a major cause of hospital-acquired and chronic infections, characterised by an extraordinary capacity to develop antimicrobial resistance through the selection of chromosomal mutations, leading to treatment failure. Here, we designed and tested a hybridisation-based capture system for the enrichment of genes of interest before sequencing to monitor resistant populations genomics directly from clinical samples. A panel for enrichment before sequencing of close to 200 genes related to P.aeruginosa antimicrobial resistance, multilocus sequence typing, mutability or virulence was designed, synthesised (KAPA HyperCap, Roche) and initially validated invitro using a multidrug-resistant ST175 isolate and representative isolates from major P.aeruginosa clades. Invivo testing included ventilator associated pneumonia by MDR P.aeruginosa in ICU (3-10 sequential samples from 3 patients) and chronic respiratory infection by hypermutable P.aeruginosa in cystic fibrosis (8 sequential samples from a single patient covering a 4-year period). Results from direct sequencing with the enrichment panel were compared with those of whole genome sequencing (WGS) and phenotypic profiling of 10 isolated colonies per sample. Invitro assays confirmed the selectivity of the enrichment panel and the correct identification of the vast mutational resistome of ST175, including specific mutations even when introduced in a 1:100 proportion. Invivo performance was at least equivalent to sequencing 10 colonies per sample, including the accurate identification of the sequence types and the basal and acquired mutational resistome. To note, specific resistance mutations, such as those in ampC leading to resistance to novel β-lactams, could be traced even at frequencies of 1%. Moreover, the coselection of mutator populations and antibiotic resistance mutations, predicted in theoretical and invitro studies, was evidenced invivo. This proof-of-concept study demonstrates that resistance genomics of P.aeruginosa can be analysed directly from clinical samples, determining not only a considerable reduction in turnaround time and cost from a diagnostics perspective, but also an unprecedented potency for accurate monitoring of invivo population dynamics in bacterial infections. Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea-NextGenerationEU.

Using real-time kinetic GPS (RTK-GPS) to improve the assessment of population dynamics and optimize population viability studies of threatened species

The conservation of threatened plant species needs precise monitoring studies to assess population trends and improve management strategies. Here, we investigated the viability of employing high-accuracy RTK-GPS technology for demographic evaluation of Euphorbia fontqueriana, a critically endangered species of the western Mediterranean Basin. Our study aimed to evaluate the utility of RTK-GPS technology, compare its applicability with traditional methods, and determine its impact on decision-making in conservation. We used permanent plots and comprehensive field surveys to monitor population dynamics, and transitions between plant stages and vital rates were recorded and analysed. Results revealed a positive population trend for E. fontqueriana, contrasting with previous studies. Vegetative stage was the most representative of the population, and high survival rates were observed for vegetative and reproductive individuals. Elasticity analysis showed higher value for vegetative stage. The study underscores the importance of employing high-accuracy plant monitoring methods for effective conservation assessments and emphasizes the potential of RTK-GPS technology in enhancing conservation efforts for threatened plant species.

Preliminary checklist of spiders (Araneae) from Coiba National Park, Panama.

Coiba National Park is an offshore region on the Pacific side of Panama, which hosts several endemic species of animals and plants. It was declared a UNESCO World Heritage Site in 2005. Despite the title awarded to the Park, knowledge about basic elements of its biodiversity are still lacking, which are of vital relevance for management and conservation policies. For instance, until now, no study had ever monitored the araneofauna diversity of the Park. Here, we provide the first checklist of spider species in Coiba National Park, including the main island and several surrounding islands. We sampled during several field trips carried out from August 2021 to August 2023. We identified at least 152 species (98 genera and 30 families) and we report three new spiders species for Panama, namely Ctenusnigrolineatus Berland (1913), Chapodagitae Zhang & Maddison (2012) and Sarindanigra Peckham & Peckham (1892). We discuss the implications of our results and recommend future lines of work that include DNA barcoding, monitoring of population and community dynamics, plus linkage of climatic data from the newly-installed meteorological station on the Island.

Advanced Computer Vision Methods for Tracking Wild Birds from Drone Footage

Wildlife conservationists have historically depended on manual methods for the identification and tracking of avian species, to monitor population dynamics and discern potential threats. Nonetheless, many of these techniques present inherent challenges and time constraints. With the advancement in computer vision techniques, automated bird detection and recognition have become possible. This study aimed to further advance the task of detecting wild birds using computer vision methods with drone footage, as well as entirely automating the process of detection and tracking. However, detecting objects from drone footage presents a significant challenge, due to the elevated altitudes, as well as the dynamic movement of both the drone and the birds. In this study, we developed and introduce a state-of-the-art model titled ORACLE (optimized rigorous advanced cutting-edge model for leveraging protection to ecosystems). ORACLE aims to facilitate robust communication across multiple models, with the goal of data retrieval, rigorously using various computer vision techniques such as object detection and multi-object tracking (MOT). The results of ORACLE’s vision models were evaluated at 91.89% mAP at 50% IoU.

Vulnerability to fluctuations in prey and predation landscape in a central place foraging marine predator

IntroductionHuman-induced environmental change is driving a global redistribution of biodiversity, resulting in shifting prey and predation landscapes. These shifting landscapes can lead to changes in behavior, health, and vital rates, with potential implications for population dynamics.MethodsIn the present study, a state-dependent life-history theory model was developed to investigate the individual- and population-level responses of Australian fur seals (Arctocephalus pusillus doriferus) to changes in prey availability and at-sea mortality risk.ResultsRates of pregnancy, pup nursing, and abortion were unaffected by prey availability in the simulated population. Likewise, on-land and at-sea durations were largely unaffected by prey availability, with more pronounced affects for nonreproductive and pregnant females than for lactating females. There was a strong influence of prey availability on the proportion of females that were concurrently pregnant and lactating, largely due to an increase in pup abandonments under low prey availability scenarios. This effect on pup abandonments also had flow on effects for pup recruitment. Increasing at-sea mortality risk resulted in greater offspring losses due to maternal death. The combined impact of prey availability and at-sea mortality risk on the number of simulated female offspring reaching sexual maturity was substantial.DiscussionConsequently, our results suggest high vulnerability of the Australian fur seal population to shifting prey and predation landscapes. These results indicate a need for continued monitoring of Australian fur seal pup production and population dynamics in the face of rapid environmental change.

Time budget of a mallard duck population residing in an urban park in northern Portugal during courtship and nesting period

Behavioural observations were used to investigate the temporal dynamics events and associated variation in the daily activities of a sedentary population of mallard duck (Anas platyrhynchos) inhabiting an urban park in northern Portugal. Data was collected at Porto City Park from December to April, during the species’ courtship and early nesting periods. The most frequent activities for this population were locomotion, resting and feeding. Statistical analysis revealed that male and female behaviours differed significantly throughout the courtship period, as males exhibited more displays and aggressive behaviour while females were more prone to feed in order to meet their increased nutritional and energetic needs. Temporal analyses showed that courtship reached a peak in intensity in February, since it was in this month that the highest values for mating, aggressive behaviour in males and defensive behaviour in females were observed. Behavioural differences were found for this population, with higher feeding rates compared to those of wild populations as well as lower defensive behaviour rates. This paper sheds light on how synanthropized populations, as well as those from Southwestern Europe, show different behavioural responses from other populations. Additional extensive monitoring of population dynamics and factors such as latitudinal differences, habituation to humans and climate change will help to predict future growth and expansion rates.

Biogeographic analysis of population density of white-tailed deer in Mexico: Importance of the Protected Natural Areas and Wildlife Management Units

The white-tailed deer Odocoileus virginianus is the wildlife species with the greatest geographic distribution and economic importance in Mexico. This article presents a biogeographic analysis of the population density of this deer species by federal states, vegetation types, biogeographic provinces, and field methods, based on 200 selected studies. Estimates are highly variable and potentially biased due to the different field designs and statistical analyses. The national average density was estimated at 6.9 deer/km2 (SD = 5.1); specifically, 75.5 % of the estimates were less than 10 deer/km2, and only 5.5 % were greater than 15 deer/km2. The highest densities were obtained in the northern region by applying the strip transect counts; while estimations using the fecal group count method were more variable and were the most used method in temperate and tropical dry forest regions. The states with the highest densities were Coahuila, Tamaulipas, Jalisco, Morelos, Michoacán, and Durango. The highest densities were estimated in the xerophilous scrublands of the northeast, intermediate for temperate, tropical dry, and sub-deciduous forests; and the lowest in the tropical wet forest. The highest densities were reported for the Tamaulipeca province followed by the Altiplano Chihuahuense, Sierra Madre Occidental, Costa Pacífica, and Depresión del Balsas. The results of this analysis could guide management strategies for the conservation and sustainable use of this species in extensive UMAs and ANPs, and also to test ecological hypotheses. However, applying more rigorous field design and statistical analysis is important to obtain confident estimates of population density and other demographic parameters to monitor population dynamics.

Phylogenetic and population genetic analyses of Thrips tabaci Lindeman (Thysanoptera: Thripidae) on Allium host in India.

Onion thrips (Thrips tabaci) is a complex of cryptic species with subtle morphological differences and distinct genetic backgrounds; thus, species identification using traditional methods remains challenging. The existence of different haplotypes and genotypes within a species can significantly influence various aspects of its biology, including host preference, reproductive capacity, resistance to pesticides, and vector competence for plant viruses. Understanding the genetic diversity and population structure of cryptic species within T. tabaci will not only aid in the development of more effective control strategies tailored to specific genetic variants but also in monitoring population dynamics, tracking invasive species, and implementing quarantine measures to prevent the spread of economically damaging thrips biotypes. This study aims to explore intraspecies genetic diversity and molecular evolutionary relationships of the mitochondrial cytochrome oxidase gene subunit I (mtCOI) in T. tabaci populations from India. To capture diversity within the Indian T. tabaci populations, amplicon sequencing was performed for the thrips mtCOI gene from eight diverse localities in India. A total of 48 sequences retrieved for the mtCOI gene from the NCBI Nucleotide database were analysed. Multiple insertions and deletions were detected at various genomic positions across the populations from different localities, with the highest variation observed in the 300-400 genome position range. Molecular diversity analyses identified 30 haplotypes within the population, with certain subpopulations exhibiting higher gene flow. Analysis of single nucleotide polymorphism patterns within the mtCOI gene across diverse Indian locales revealed significant intrapopulation genetic heterogeneity and its potential repercussions on gene functionality. Elevated F statistics (Fst) values in the northern-western subpopulations suggested high genetic variability, particularly evident in haplotype networks originating mainly from the northern region, notably Delhi. While most populations displayed stable and ancient evolutionary histories, thrips populations from northern, western, and north-eastern regions indicated rapid growth.

Городская популяция кряквы (Anas platyrhynchos) в Саратове: зимовка, гнездование, степень синантропизации

The article reflects data on year-round studies of the urban mallard population in Saratov, allowing the assessment of the condition and the study of the factors influencing its formation. An estimate of the mallard population in the winter periods of 2020–2023 is presented. It is shown that the number negatively correlates with frosts and precipitation, and there is a statistically significant positive relationship between the number of people feeding ducks and the number of mallards. The state of the wintering and nesting population is assessed according to the index of synanthropization, the rate and path of penetration of the species into urbanized landscapes, and the stage of formation of the urban population in Saratov is determined. Adaptations of mallards to life in urban conditions and their impact on the ecology of the species as a whole are highlighted. The article emphasizes the need for further research on the impact of urbanization on mallard ecology and the benefits of this species for the urban ecosystem. The importance of monitoring population dynamics for its adaptation to the urban environment and maintaining the stability of the entire population is noted. In addition, the article provides a basis for further studies of the urban mallard population and can be a valuable source of information for the development of local programs for managing the available resources of ducks living in the park area of the city.

Exogenous salicylic acid induces defense responses in tea plants against Toxoptera aurantii (Hemiptera: Aphididae).

Toxoptera aurantii is one of the most destructive pests, threatening the yield and quality of tea plantations. The salicylic acid (SA)-mediated signaling pathway is vital for the induction of plant defense responses; however, its role in tea plant resistance to T. aurantii remains unclear. Thus, this study used and electrical penetration graph and monitoring of population dynamics to evaluate the effects of exogenous SA application on T. aurantii feeding behavior and population growth in tea seedlings. Moreover, the effects of SA treatment on the activities of defense-related enzymes were analyzed. Probe counts and the duration of xylem sap ingestion were significantly higher in SA-treated plants than those in the control group. The total duration of passive phloem ingestion was significantly decreased in 0.5 mmol/l SA-treated plants, and the application of 0.5, 1, and 4 mmol/l SA significantly inhibited T. aurantii population growth. In addition, the activities of polyphenol oxidase, peroxidase, and superoxide dismutase were significantly increased in the 0.5 mmol/l SA-treated plants. Overall, this study demonstrates the capacity of exogenous SA to activate defense responses against T. aurantii. These results have crucial implications for understanding the mechanisms of enhanced resistance, thereby providing a sustainable approach for managing T. aurantii.

Monitoring wildlife population trends with sample counts: a case study on the Alpine ibex (Capra ibex)

Monitoring population dynamics is of fundamental importance in conservation but assessing trends in abundance can be costly, especially in large and rough areas. Obtaining trend estimations from counts performed in only a portion of the total area (sample counts) can be a cost‐effective method to improve the monitoring and conservation of species difficult to count.We tested the effectiveness of sample counts in monitoring population trends of wild animals, using as a model population the Alpine ibex Capra ibex in the Gran Paradiso National Park (Italy), both with computer simulations and using historical count data collected over the last 65 years. Despite sample counts failed to correctly estimate the true population abundance, sampling half of the target area could reliably monitor the trend of the target population. In case of strong changes in abundance, an even lower proportion of the total area could be sufficient to identify the direction of the population trend. However, when there is a high yearly trend variability, the required number of samples increases and even counting in the entire area can be ineffective to detect population trends. The effect of other parameters, such as which portion of the area is sampled and detectability, was lower, but these should be tested case by case.Sample counts could therefore constitute a viable alternative to assess population trends, allowing for important, cost‐effective improvements in the monitoring of wild animals of conservation interest.

Automatic pest identification system in the greenhouse based on deep learning and machine vision.

Monitoring and understanding pest population dynamics is essential to greenhouse management for effectively preventing infestations and crop diseases. Image-based pest recognition approaches demonstrate the potential for real-time pest monitoring. However, the pest detection models are challenged by the tiny pest scale and complex image background. Therefore, high-quality image datasets and reliable pest detection models are required. In this study, we developed a trapping system with yellow sticky paper and LED light for automatic pest image collection, and proposed an improved YOLOv5 model with copy-pasting data augmentation for pest recognition. We evaluated the system in cherry tomato and strawberry greenhouses during 40 days of continuous monitoring. Six diverse pests, including tobacco whiteflies, leaf miners, aphids, fruit flies, thrips, and houseflies, are observed in the experiment. The results indicated that the proposed improved YOLOv5 model obtained an average recognition accuracy of 96% and demonstrated superiority in identification of nearby pests over the original YOLOv5 model. Furthermore, the two greenhouses show different pest numbers and populations dynamics, where the number of pests in the cherry tomato greenhouse was approximately 1.7 times that in the strawberry greenhouse. The developed time-series pest-monitoring system could provide insights for pest control and further applied to other greenhouses.

Long-Term Monitoring of Tree Population Dynamics in Desert Ecosystems: Integrating Field and Satellite Data

Arid environments are characterized by rare rain events that are highly variable, as a result of which plant populations often exhibit episodic recruitment and mortality dynamics. However, direct records and observations of such events are rare because of the slow development of woody species. In this study, we described how a decrease in annual precipitation affected acacia tree population dynamics in two hydrological regime types: small wadis and salt flats. This study combines 15 years of continuous, yearly field monitoring of individual acacia trees and data from a historical Corona satellite image, which has extended the time scope of the research. Results indicate that the annual mortality of acacia trees in small wadis reflects the cumulative effective rain events in the preceding five years, whereas the population on the salt flats was not affected by annual rainfall fluctuations. Moreover, in small wadis, rain events of less than 8 mm did not increase acacia tree survival rates. The mortality pattern and dynamics of each plot was unique, suggesting unsynchronized mortality and recruitment episodes on a regional scale. Mortality in all plots was documented both in “old” trees (i.e., recognized in 1968) and “new” trees (not recognized in 1968), but varied highly between plots. More than 50% of the dead trees recorded at the sites had died during the previous dry period (2000–2010). Combining field monitoring and historical satellite image data provided a unique database of acacia population dynamics. This record revealed the response of the acacia population to climate fluctuations and a period of episodic mortality.

Landscape Dynamics and Ecological Risk Assessment of Cold Temperate Forest Moose Habitat in the Great Khingan Mountains, China.

The change in habitat pattern is one of the key factors affecting the survival of the moose population. The study of the habitat landscape pattern is the key to protecting the Chinese cold-temperate forest moose population and monitoring the global distribution of moose. Through the ecological risk assessment of the moose habitat landscape pattern in a cold-temperate forest, we hope to assess the strength of habitat resistance under stress factors. This study provides a theoretical basis for the protection of the moose population in the cold-temperate forest in China and the establishment of the cold-temperate forest national park. In the study, the MaxEnt model, landscape index calculation and ecological risk assessment model construction were used to analyze the field survey and infrared camera monitoring data from April 2014 to January 2023. The habitat suitability layer of the moose population in the Nanwenghe National Nature Reserve of the Great Khingan Mountains was calculated, and the range of the moose habitat was divided based on the logical threshold of the model. The landscape pattern index of the moose habitat was calculated by Fragstats software and a landscape ecological risk assessment model was established to analyze the landscape pattern and ecological risk dynamic changes of the moose habitat in 2015 and 2020. The results showed that under the premise of global warming, the habitat landscape contagion index decreased by 4.53 and the split index increased by 4.86 from 2015 to 2020. In terms of ecological risk: the area of low ecological risk areas increased by 0.88%; the area of medium ecological risk areas decreased by 1.11%; and the area of high ecological risk areas increased by 0.23%. The fragmentation risk of the landscape pattern of the moose habitat tends to increase, the preferred patch type is dispersed, the degree of aggregation is low, and the risk of patch type transformation increases. The middle and high ecological risk areas are mainly concentrated in the river area and its nearby forests, showing a fine and scattered distribution. Under the interference of global warming and human activities, the fragmentation trend of the moose habitat in the study area is increasing, and the habitat quality is declining, which is likely to cause moose population migration. For this reason, the author believes that the whole cold temperate forest is likely to face the risk of increasing the transformation trend of dominant patch types in the cold-temperate coniferous forest region mainly caused by global warming, resulting in an increase in the risk of habitat fragmentation. While the distribution range of moose is reduced, it has a significant impact on the diversity and ecological integrity of the whole cold-temperate forest ecosystem. This study provides theoretical references for further research on the impact of climate warming on global species distribution and related studies. It is also helpful for humans to strengthen their protection awareness of forest and river areas and formulate reasonable protection and sustainable development planning of cold-temperate forests. Finally, it provides theoretical references for effective monitoring and protection of cold-temperate forests and moose population dynamics.

Engineering RNA export for measurement and manipulation of living cells

A system for programmable export of RNA molecules from living cells would enable both non-destructive monitoring of cell dynamics and engineering of cells capable of delivering executable RNA programs to other cells. We developed genetically encoded cellular RNA exporters, inspired by viruses, that efficiently package and secrete cargo RNA molecules from mammalian cells within protective nanoparticles. Exporting and sequencing RNA barcodes enabled non-destructive monitoring of cell population dynamics with clonal resolution. Further, by incorporating fusogens into the nanoparticles, we demonstrated the delivery, expression, and functional activity of exported mRNA in recipient cells. We term these systems COURIER (controlled output and uptake of RNA for interrogation, expression, and regulation). COURIER enables measurement of cell dynamics and establishes a foundation for hybrid cell and gene therapies based on cell-to-cell delivery of RNA.

Wolverine denning behaviour and its implications for monitoring reproductive females

Knowledge about the number of reproductive females is important for monitoring population dynamics, and can be critical for managing human–wildlife conflicts. For wolverines Gulo gulo, counts of reproductive females is the basis for estimates of population size in Scandinavia, as well as a key measure for compensation payments to Sámi reindeer‐herders in Sweden. However, documenting wolverine reproductive events in the field is challenging and requires knowledge of female denning behaviour. Furthermore, females may shift den sites, presenting difficulties in determining whether two den sites belong to the same or two neighbouring females. In this study, we used data from 18 GPS‐collared wolverine females, monitored intensively during the denning season (15 February–31 May) in 2004–2014, to provide baseline information on denning behaviour. We documented reproductive events in 32 of 54 potential denning seasons, and identified a total of 245 den sites. Females used 8.8 ± 8.5 (mean ± SD) den sites per denning season (median = 6, range: 1–28). The number of den site shifts, the distance between subsequent den sites, and the time and distance females spent away from a den site increased during the denning season; while distances between neighbouring females' den sites remained constant. From late April, the distance between consecutive den sites used by the same female overlapped with distances between neighbouring females' den sites, resulting in increased uncertainty regarding whether two den sites belonged to one or two females. Using Bayesian modelling we calculated probabilities that two den sites belonged to the same female, or neighbouring females, conditional on the time of season and the distance between den sites. These findings will allow the monitoring program to adapt its methods for determining if multiple den sites belong to one or two reproductive events, using seasonally‐dynamic threshold based on an understanding of wolverine denning behaviour.

Occurrence of plant pathogenic Pseudomonas syringae in the Danube River Basin: abundance and diversity assessment

Plant pathogenic strains of Pseudomonas syringae (Psy) spp. have been detected in nonagricultural habitats, including those associated with the water cycle. Their presence in aquatic systems allows dissemination over long distances, especially with irrigation practices. In May 2021, we sampled 15 sites along the Danube River Basin in Serbia to gain insight into P. syringae abundance and diversity. We identified 79 Psy strains using Psy-specific primers, and a partial sequence of the citrate synthase (cts) house-keeping gene has served for phylogenetic diversity assessments. Phenotypic diversity determination included characterizing features linked with survival and pathogenic lifestyle. The ice nucleation activity, pectinolytic activity, swimming and swarming assays, and hypersensitive reaction on plants were tested. Psy was detected at ten of 15 sites examined at abundance ranging from 1.0 × 102 to 1.2 × 104 CFU/L. We discovered the presence of four phylogroups, with phylogroup 2 being the most abundant, followed by phylogroups 7, 9, and 13. The hypersensitive reaction was induced by 68.63% of the isolates from the collection. A partial sequence comparison of the cts gene showed 100% similarity between isolates from cherry plants epidemics in Serbia caused by Psy and isolates from the Danube River. Our results suggest that the Danube River, extensively used for irrigation of agricultural fields, harbors diverse strains of Psy, which possess various features that could lead to potential disease outbreaks on crops. This study represents the first in-depth analysis of Psy abundance and diversity in the Danube River Basin. It sets the ground for future pre-epidemic studies and seasonal monitoring of Psy population dynamics.

Monitoring of the Brown marmorated stink bug Halyomorpha halys (Stål, 1855) in Banja Luka, Bosnia and Herzegovina

Brown marmorated stink bug Halyomorpha halys (Stål, 1855) is an invasive and polyphagous stink bug native to Asia. It has recently invaded Europe and Bosnia and Herzegovina. It is highly polyphagous pest of many economically important commodities including tree fruit, nut crops, field crops, vegetables and ornamentals. Moreover, it is an important nuisance pest because large numbers of adults seek out artificial structures for overwintering. Monitoring of population dynamics of H. halys during two years (2020 and 2021) was performed in Banja Luka, Bosnia and Herzegovina. The pest was present through monitoring period April–October with the highest abundance in the third decade of July when all life stages were present. More individuals were caught on pyramid trap (845) compared to sticky trap (156) favoring pyramid trap for future monitoring. Total number of caught individuals was 6.5 folds higher in the second year of the monitoring indicating population increase that presents threat to agricultural production.