Abstract Background Phloem-sap-feeding planthopper Reptalus artemisiae is an emerging vector of rubbery taproot disease (RTD) and syndrome basses richesses (SBR) in sugar beet, diseases associated with 'Candidatus Phytoplasma solani' and 'Candidatus Arsenophonus phytopathogenicus', respectively. Despite studies on related cixiids, the microbiome of R. artemisiae remains uncharacterized. Using a PCR-free metagenomic long-read shotgun sequencing approach, this study investigates the bacterial diversity associated with R. artemisiae, and provides genomic insight into two plant pathogens 'Ca. P. solani' and 'Ca. A. phytopathogenicus'. Results Taxonomic assignment revealed six prokaryotic taxa in R. artemisiae: two plant pathogens ('Ca. P. solani' and 'Ca. A. phytopathogenicus') and four insect endosymbionts – three primary endosymbionts ('Candidatus Vidania', 'Candidatus Purcelliella', and 'Candidatus Karelsulcia') and a secondary endosymbiont (Wolbachia). Community profiles showed a consistent presence of all four endosymbionts across five evaluated R. artemisiae individuals. Phylogenetic analyses of 16S rRNA gene sequences of primary endosymbionts confirmed strong congruence with the cytochrome oxidase subunit I phylogeny of the insect host, indicative of long coevolution and vertical transmission. In contrast, plant pathogen presence in R. artemisiae varied, with 'Ca. P. solani' and 'Ca. A. phytopathogenicus' each detected in three individuals. Genome assembly yielded a complete 774 kb circular chromosome for 'Ca. P. solani' with streamlined metabolism featuring limited biosynthetic pathways, but a full arsenal of genes related to host–pathogen interactions and pathogenicity typical for this biotrophs. The draft genome of 'Ca. A. phytopathogenicus' comprising 18 scaffolds totalling 3.11 Mb and two plasmids shows a self-sufficient metabolism with several missing metabolic modules and presence of genomic islands, virulence factors, and a dynamic mobilome indicating a bacterium in transition that is reorganizing its genetic material, possibly in response to host interactions. Conclusion These findings represent the first in-depth characterization of R. artemisiae microbiome, highlighting a stable endosymbiont consortium and variable pathogen presence that emphasize ecological complexity in vector-pathogen-endosymbiont interactions. The assembled genomes enhance the understanding of microbial ecology, pathogen adaptation and transmission, offering resources for comparative genomics and potential applications in disease management strategies.
Voles and Apodemus mice are recognized as important hosts for numerous parasites and pathogens. Understanding the occurrence of zoonoses, key host characteristics, and the factors influencing their population dynamics and distribution is essential for predicting disease occurrence and assessing the risks of transmission and spread. Determining the role of voles and field mice, in maintaining Borrelia burgdorferi, s.l. in the environment clarifies its transmission during tick activity periods and highlights the need for timely monitoring and control measures. We examined the prevalence of Borrelia burgdorferi sensu lato in solid heart tissue of small rodent species (Clethrionomys glareolus, Apodemus spp., Microtus spp.). Detection and molecular typing of bacteria was completed using real-Time PCR and Sanger sequencing. The presence of the pathogen Borrelia afzelii in voles (Microtus arvalis, C. glareolus) and mice (Apodemus agrarius, Apodemus sylvaticus) was recorded in Serbia for the first time during this study. The prevalence of B. burgdorferi s.l. infection in the collected M. arvalis and C. glareolus was 12.9
Higher plants provide suitable habitats for mites (Acari), the second most numerous group of arthropods [...]
Understanding of the processes that affect soil herbicide behaviour enables the prediction of their fate in the environment. Soil-herbicide interactions are governed by adsorption-desorption processes as only the free herbicide fraction participates in all other processes occurring in or on the soil. Given the agricultural and environmental significance of clomazone, its adsorption-desorption behaviour was investigated in two widely distributed Serbian agricultural soil types, Planosol and Vertisol. Both processes were well-described by Freundlich isotherms, and the obtained sorption parameters show that clomazone sorbed to both organic matter and mineral soil components. Vertisol, characterized by higher organic matter and clay content, demonstrated greater sorption capacities (3.67-21,23 mg^{n-1/n} dm^{3/n} kg^{-1} for 1.5-15 mg dm^{-3} ) and lower desorption rates (the amounts desorbed of 29.49-28.48 % during 72 h for 1.5-15 mg dm^{-3} ) compared to Planosol (3.15-18.35 mg^{n-1/n} dm^{3/n} kg^{-1} and 33.32-29.97 % for 1.5-15 mg dm^{-3} ). The more pronounced desorption hysteresis observed in Vertisol is likely attributable to the presence of a higher number of high-energy sorption sites compared to Planosol. These findings highlight the crucial role of soil composition in determining the environmental fate of clomazone, providing a valuable basis for developing agronomically effective and environmentally safe application recommendations.
Fluxametamide, an isoxazoline compound, is a novel broad-spectrum insecticide and acaricide with a neurotoxic mode of action, is intended for use against lepidopteran, thysanopteran, coleopteran, hemipteran and dipteran pest species, as well as spider mites. Its effects on life-history and population parameters of the predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were assessed in demographic bioassay using the age-stage two-sex life table. Fluxametamide was applied against 24-h old adult females at LC10 and LC30 (the concentrations obtained in previously conducted acute toxicity bioassay) and the effects were evaluated on their offspring. Three cohorts (two acaricide treatments and a control) of 45 eggs each were formed. The eggs were laid by the females exposed for 24 h to fluxametamide residues on bean leaf discs. Developmental time, survival, and the number of eggs laid were checked daily, until all individuals were dead. To provide a food supply for the predator, 4–6 Tetranychus urticae Koch immatures were added several times per day. The raw life history data were analyzed using the TWOSEX MSChart software. The following parameters were estimated: pre-adult developmental time (Pa, days), total preoviposition period (TPOP, days), fecundity (eggs female-1), adult longevity (days), oviposition period (days), total life span (days), gross reproductive rate (GRR, eggs laid), net reproductive rate (R0, eggs mite-1), intrinsic rate of increase (r, days-1) and finite rate of increase (λ, days-1). Standard errors of the parameters were estimated by the bootstrap technique with 100,000 replicates, and the differences between control and treatments were compared by the paired bootstrap test. Fluxametamide differentially affected population growth of A. swirskii. Applied at LC10, the acaricide significantly reduced GRR (8.78), R0 (7.68), r (0.122) and λ (1.130), compared to the control (GRR = 14.25, R0 = 12.24; r = 0.142; λ = 1.152), and this reduction was largely the consequence of significant reduction in adult longevity (females: 22.10, males: 20.36; in the control: 24.31 and 22.09) and fecundity (11.93; in the control: 19.00). On the other hand, the application at LC30 caused a significant increase in GRR (18.16), R0 (16.25), r (0.188) and λ (1.207), compared to the control, mainly due to a significant shortening of TPOP (8.68; in the control: 10.17) and a significant increase in fecundity (22.64).
