Mariusz Lewandowski

Interactions between plant viruses and their arthropod vectors can extend beyond transmission and influence vector fitness-related traits. Wheat streak mosaic virus (WSMV) is one of the most important viral pathogens of wheat and is transmitted by the wheat curl mite, Aceria tosichella Keifer. The objective of this study was to determine whether WSMV influences population growth of the MT-1 lineage of A. tosichella through plant- mediated effects, vector-mediated effects or both. The experiment was conducted on wheat plants (var. Muszelka) under three treatments: (1) aviruliferous mites on healthy plants (control), (2) aviruliferous mites on WSMV-infected plants, and (3) viruliferous mites on healthy plants. In each treatment, five adult females were transferred to single plants. After two weeks, the total population (eggs + motile stages) was counted and used to estimate the population growth rate. Population growth differed significantly (ANOVA, p = 0.0008) among treatments. Both aviruliferous mites on WSMV-infected plants and viruliferous mites on healthy plants showed significantly higher growth rates than control treatment. The two virus-associated treatments did not differ significantly from each other. The findings suggest that WSMV positively influences the population growth of the MT-1 lineage of A. tosichella through both plant- and vector-mediated pathways, which may contribute to increased vector abundance in wheat fields. In conclusion, such positive effects on vector performance could strengthen the epidemiological success of WSMV- A. tosichella pathosystem.

The wheat curl mite (WCM, Aceria tosichella) is the vector of several globally important cereal viruses. However, WCM populations are genetically structured, and major mitochondrial lineages such as MT-1 and MT-8 differ in traits relevant to epidemiology, including host use, invasiveness, and vector competence. In Australia, the epidemiology of WCM-transmitted viruses is still not well understood, despite the presence of wheat streak mosaic virus (WSMV, Tritimovirus tritici) and High Plains wheat mosaic emaravirus (HPWMoV, Emaravirus tritici) in cereal systems. Current management strategies are still shaped largely by studies from the U.S. Great Plains, while major gaps remain in our understanding of how these viruses interact with mites and how they are transmitted. This presentation will provide a brief overview of current knowledge of the WCM-virus complex and highlight the main knowledge gaps. It will also present results from our study on WSMV accumulation in two major WCM lineages, MT-1 and MT-8. Using direct RT-qPCR we compared virus titers in immature mites after feeding on infected wheat and throughout development to the adult stage by quantifying viral loads in individual mites. We also related these patterns to known differences in transmission efficiency between MT-1 and MT-8. Our study was designed to test whether lineage-specific vector competence is linked to differences in virus uptake, retention, and possible replication, with particular attention to virus titers at different mite developmental stages. Comparative analyses of MT-1 and MT-8 suggest that differences in virus accumulation could be linked to contrasting transmission outcomes. These findings also help to explain why some WCM lineages play a bigger role in cereal virus epidemiology than others. Overall, this work highlights the need for further studies on mite-virus interactions and for closer integration of vector biology into cereal virus epidemiology. Understanding how WSMV is acquired, retained, and transmitted by different WCM lineages is essential for improving surveillance, resistance breeding, and management strategies in Australia and elsewhere.

The confirmed role of Tomato Russet Mite (TRM), Aculops lycopersici (Trombidiformes: Eriophyoidea), as a biological vector for Tomato Fruit Blotch Virus – ToFBV (Blunervirus solani) belonging to kitaviridae family — marks a paradigm shift in its phytosanitary importance. Evidence shows TRM successfully acquires and transmits ToFBV across various phenological stages. Recent insights into ToFBV epidemiology, including precise tissue localization and the exclusion of vertical seed transmission, underscore the mite vector’s indispensable role in viral dispersal. The potential for other solanaceous species to serve as reservoirs is currently under investigation and is crucial for understanding how specialized agricultural strains transition to alternative hosts, ultimately contributing to the development of more effective cross-crop management and forecasting strategies. This study evaluates the reproductive fitness of a TRM population adapted to tomato, quantified through the population growth rate (r) across a selection of diverse host plant species by reflecting the mean growth performance, under controlled laboratory conditions, serving as an indicator of the pest’s host-shifting potential and invasive capacity. Our findings revealed that tomato-adapted TRM populations exhibit varied fitness across the Solanaceae family (Solanum nigrum, Convolvulus arvensis, Capsicum annuum, Nicotiana tabacum, and Petunia spp.), all supporting positive growth. Reciprocal transfer experiments further highlighted host-specific adaptation, confirming the mite’s high ecological plasticity. Black nightshade (Solanum nigrum) is a critical alternative host and ubiquitous weed that serves as a significant reservoir for both the mite and the virus. Notably, S. nigrum proved as suitable as tomato, facilitating robust fecundity and a female-biased sex ratio. Managing these wild hosts is essential for refining Integrated Pest Management (IPM) strategies to prevent rapid recolonization and sustained inoculum pressure. Our findings identify S. nigrum as the primary «green bridge» for overwintering and re-infestation. While taxonomically distant species like field bindweed and white goosefoot show lower suitability, they may sustain residual populations under favorable conditions. Effective IPM must prioritize the eradication of these weed reservoirs. Given limited varietal resistance, developing resistant germplasm is a research priority to mitigate the global economic risks posed by the TRM–ToFBV complex.

The work presented in this article concerns numerical studies on optimization methods used for the sustainable utilization of the energy potential of water, converting it into electricity in a hydropower plant equipped with more than one unit. These methods allow for maximization of production in given hydrological conditions, leading to the balanced, lossless, and environmentally friendly use of the renewable energy source that is water. Methods are selected from three groups, i.e., analytical, enumeration, and randomized. The results of calculations of optimal points of selected test functions carried out using the Broyden–Fletcher–Goldfarb–Shanno Limited-Memory Version (L-BFGS-B), Explicit Complete Enumeration (ECE), and Genetic Algorithm (GA) methods provided basic information on the features of these methods. Based on these tests, the GA method was selected to solve the problem of the optimal load distribution in a hydropower plant equipped with three identical hydro units. The defined optimization problem consisted of finding a configuration of hydro units in operation that would guarantee the maximum efficiency of the power plant under the imposed hydrological conditions. During the numerical studies, a number of calculations were performed to identify the impact of procedures and parameters characteristic of the optimization methods on the obtained results. Particular attention was paid to the GA method and penalty functions, enabling the elimination of results from the area of prohibited solutions.

This paper presents the results of laboratory tests of water hammer phenomenon induced in two series-connected copper pipes with different diameters (a diameter ratio of 1:1.25) by a quick-closing valve installed at the end of the simple upstream tank–pipeline–valve system. Test results were compared with calculations made with the use of various friction loss models incorporated in a one-dimensional model based on a method of characteristics. The calculation takes into consideration quasi-steady and unsteady friction models as well as a special discretization procedure of the solution domain that ensures the elimination of numerical diffusion in the numerical scheme. The main attention was paid to determining the value of the pressure wave speed in the pipes, which has a significant influence on the compliance between the calculations and the experimental results of the pressure amplitudes and wave frequencies. Two methods of determining the wave speed were proposed and evaluated based on the measurements. The results presented in this article indicate that the use of the proposed procedure instead of the classic formulas for determining the pressure wave speed gives the desired correspondence between the frequencies of the measured and calculated waves. Calculation examples made with the use of different friction models showed that application of the developed procedure for discretization of the solution domain and the method used for determining the wave speed opened the possibility of reliable verification of these models, free of numerical errors and frequency discrepancies between the computational and measured wave.

W referacie dokonano szacunkowej oceny zdolności magazynowania energii w eksploatowanych w Polsce elektrowniach zbiornikowych i szczytowo-pompowych oraz podano najczęściej występujące ograniczenia ich wykorzystania, ze wskazaniem na formalne i techniczne warunki usuwania tych ograniczeń. Oceniono również aktualne zdolności elektrowni wodnych do świadczenia usługi elastyczności oraz zaprezentowano rozwiązania techniczne zwiększające te zdolności, które z powodzeniem można wdrożyć w większości eksploatowanych elektrowni wodnych.

This article presents the original procedures for measuring the flow rate using the pressure-time and the volumetric gauging method in the case of performance tests of a reversible hydraulic machine in either turbine or pump modes of operation. Achieving the lowest possible measurement uncertainty was one of the basic conditions during implemented machine tests. It was met using appropriate measuring procedures and high-class measuring equipment. Estimation of the uncertainty for both methods was made on the basis of an analysis consistent with current requirements in this respect. The pressure-time method was supplemented by the computational fluid dynamics (CFD) analysis that allowed reducing the impact of the pipeline complex irregular geometry on the uncertainty of flow measurement. Appropriate modifications of the calculation procedure enabled accurate measurements of flow during the pump mode of operation of the tested machine as well. The volumetric gauging method, thanks to a special procedure used for accurate measurement of the water level in the upper reservoir of the power plant, allowed measuring the discharge through the tested reversible machine with very low uncertainty. The obtained results allowed for a detailed comparison and mutual verification of the methods used to measure the discharge of the tested reversible machine in both modes of its operation. The most possible causes of obtained results are discussed and summarized in the paper. The need for further research was pointed out to explain the differences obtained and their influence on the accuracy of discharge measurement using the pressure-time method in pump operation mode.

The authors previously described a new method [based on the new discrete vapor cavity model (new DVCM)] for numerical prediction of pressure changes during the water hammer with liquid column separation together with results of preliminary experimental verification of this method. This paper is a continuation of the research and includes results of additional laboratory tests and visualization of the cavitation zones generated during transient flow with liquid column separation. The results of these studies provide a better understanding of the phenomenon. It is shown that the phenomenon can have a distributed nature, which means that gas-vapor zones may be observed not only locally, in the vicinity of the shutoff valve, but may be spread along the pipeline length, and the intensity of this phenomenon decreases with distance from the valve. Laboratory test results were also used for further verification of the new DVCM. This verification shows that agreement between calculated and experimental res...