Search Results (619)

Litter and understory are key components of forest ecosystems, playing vital roles in soil carbon inputs and microhabitat regulation. Their removal is a common forest management practice: litter removal (L) reduces fire and pest risks while promoting nutrient cycling, whereas understory removal (U) alleviates nutrient competition between understory plants and trees. However, the combined effects and underlying mechanisms of litter removal (L) and understory removal (U) on soil nematode communities remain unclear. This study investigated the individual and interactive effects of L and U on soil nematode communities in a coniferous–broadleaved mixed forest in a subtropical–warm temperate transition zone. The results showed that L significantly reduced soil nematode abundance by 18.1%, increased the relative abundance of bacterivores and omnivores-predators by 21.1% and 103.3%, respectively. U significantly elevated the relative abundance of fungivores by 30.8%, while both L and U reduced the relative abundance of plant-parasitic nematodes. Significant interactive effects between L and U were observed on soil nematode abundance, relative abundances of fungivores, plant-parasites, maturity index, and plant parasite index. Litter plus understory removal (LU) alleviated soil nematode resource limitation through synergistic regulation of resource pulses and microhabitat modification. Faunal analysis based on structure and enrichment indices indicated that LU enhanced food web structural complexity and resource-use efficiency. Redundancy analysis identified microbial biomass carbon, microbial biomass nitrogen, and soil total carbon as key drivers of nematode community differentiation. This study reveals the synergistic regulatory patterns of litter and understory vegetation on soil nematode communities, providing a theoretical reference for understanding the responses of soil nematodes to understory disturbance during the growing season in climate transitional forests, and offering basic data for long-term monitoring and forest soil management. Full article

Rhipicephalus microplus ticks harm cattle health and productivity. Frequent use of ixodicides can result in resistant tick populations and environmental contamination, as residues enter soil. Nematophagous (NF) and entomopathogenic fungi (EF) are natural enemies of nematodes and insect pests. This study tested the in vitro lethal effects of liquid culture filtrates (LCFs) from selected NF on R. microplus. Fungi were grown in Czapek-Dox broth for 30 days at room temperature to obtain LCFs, which were tested using the immersion method. Experimental groups included: (1) Arthrobotrys musiformis, (2) Purpureocillium lilacinum, (3) Flavocillium subprimulinum, (4) Lecanicillium psalliotae, (5) ixodicide mixture (permethrin and chlorpyrifos), (6) negative control (water), and (7) negative control (Czapek-Dox broth). Differences in tick mortality among filtrate treatments starting on day 10 were observed. Filtrates from L. psalliotae and A. musiformis caused the highest mortality, with A. musiformis reaching 40% and L. psalliotae 33.3% on days 14, 16, and 18 (p < 0.01). We anticipated that combining ixodicides would lead to substantial tick mortality; however, the ixodicidal compounds (chlorpyrifos and permethrin) resulted in 33.3% mortality by day 18, which was similar to that observed for L. psalliotae during the same period. Filtrates from P. lilacinum and F. subprimulinum had no effect. The ixodicide treatment led to a significant reduction in oviposition, averaging 69.8% (p < 0.05). LCFs of selected NF could be used against either nematodes or R. microplus ticks. Full article

Pine wilt disease (PWD), caused by the pine wood nematode Bursaphelenchus xylophilus, is one of the most devastating forest diseases in Asia and Europe. In addition to causing rapid pine mortality, it can alter soil nutrient status and soil nitrogen transformation processes. At the same time, nitrogen (N) deposition is an important external nitrogen input to forest ecosystems and may further influence rhizosphere nitrogen dynamics under B. xylophilus infection; however, its effects on N forms and microbial community characteristics in the rhizosphere soil of infected pine trees remain poorly studied. Therefore, this study aimed to investigate the effects of simulated N deposition on PWD, rhizosphere soil chemical properties, and rhizosphere microbial community characteristics under B. xylophilus infection, by inoculating 4-year-old Pinus thunbergii seedlings with ddH₂O (CK) and B. xylophilus (BX). For each inoculation condition, two simulated N deposition levels (N1: 50 mg N kg⁻¹ dry soil; N2: 100 mg N kg⁻¹ dry soil) and one control without N deposition (N0) were established. Generally, simulated N deposition significantly prolonged disease progression in B. xylophilus-infected pines, with mean times of 32, 43, and 46 days for BXN0, BXN1, and BXN2, respectively, and rhizosphere NO₃⁻–N and NH₄⁺–N contents were significantly higher in N1 and N2 for both the CK and BX groups. Under the same N deposition, BX treatment significantly enhanced the accumulation of NO₃⁻–N but had a limited effect on NH₄⁺–N. The microbial community analysis indicated that Ascomycota, Mortierellomycota, and Basidiomycota were the dominant fungal phyla across all experimental groups, while the Talaromyces, Apiotrichum, and Aspergillus genera showed significant abundance changes between the CK and BX groups. In addition, Actinobacteriota, Proteobacteria, and Acidobacteriota were the top bacterial phyla across all experimental groups, while the genera Nocardioides and RB41 showed changes in relative abundance between the CK and BX groups. These findings suggest that short-term nitrogen deposition can influence the PWD process and modulate rhizosphere nitrogen dynamics and microbial community structure. Full article

Human intestinal nematode infections (HINIs) remain a public health concern despite reduced prevalence following mass drug administration (MDA) in low- and middle-income countries. Children continue to bear a substantial burden of infection, and caregiver knowledge and practices may influence their risk of acquiring infection. Sustaining control during the transition of prevention programmes to surveillance-based strategies requires an understanding of behavioural determinants of transmission. Therefore, we assessed caregiver knowledge, attitudes, and practices (KAP) and their associations with sociodemographic characteristics and child infection status. A community-based cross-sectional study was conducted among 945 caregivers of primary school children in Anuradhapura, a low-prevalence setting where school-based MDA ceased in 2019, to assess caregiver KAP and child HINI status. An interviewer-administered questionnaire assessed KAP, sociodemographic, water, sanitation, hygiene (WASH), and behavioural factors. Participants were predominantly mothers (89.5%). Good knowledge was observed in 61.7%, positive attitudes in 95.6% and good practices in 99.2%. Knowledge gaps persisted regarding transmission and complications. Higher caregiver knowledge (OR = 0.52; 95% CI: 0.36–0.72) and regular deworming (OR = 0.58, 95% CI: 0.40–0.83) were associated with lower odds of infection, whereas attitudes and practices were not independently associated. Caregiver knowledge remains a key determinant of infection risk. Gaps in knowledge, misconceptions, and practices may sustain transmission even in low-prevalence settings. Strengthening health education, school-based hygiene promotion, and community engagement remains essential to reinforce preventive behaviours and support long-term control as countries transition from routine MDA to elimination-oriented strategies. Full article

The sustainable management of chemical fumigants in intensive horticulture represents one of the most complex challenges in European agricultural policy, requiring the integration of agronomic knowledge, regulatory frameworks, economic viability, and stakeholder perspectives. This study proposes and tests a multi-phase consultation methodology designed to bridge the gap between individual expert knowledge and collective, evidence-based consensus, moving from qualitative field-based elicitation to structured multidisciplinary engagement and incorporating both scientific data and practical experience. A total of 72 experts were involved across two phases. In phase 1, in-depth face-to-face interviews (n = 18) captured field-level knowledge on integrated pest management strategies, risk perception, and decision-making criteria, including the economic sustainability of production systems, a dimension prioritized in the European Commission’s Vision for Agriculture and Food. Phase 2 consisted of a one-day multistakeholder event (n = 54)—bringing together researchers, regulators, industry representatives, and farmers—to confront qualitative findings with experimental data on operator safety, groundwater protection, and consumer residues. This deliberate transition from individual perception to informed, shared consensus represents the methodological core of the approach and its most distinctive contribution. The phase 1 results showed that the majority of experts considered chemical fumigants currently indispensable, while recognizing complementary strategies—particularly solarization and natural substances—as valuable supporting tools. The phase 2 experimental data confirmed operator exposure below regulatory thresholds, no groundwater contamination under professional application conditions, and the absence of detectable residues in treated crops. The results demonstrate that this structured consultation can generate actionable knowledge for integrated nematode and soil-borne disease management, with a methodology replicable across other complex regulatory and agronomic contexts within the European framework. Full article

Environmental gradients associated with continentality shape terrestrial ecosystems by modifying biodiversity patterns, community structure, and ecosystem functioning. In arid ecosystems, where water and thermal constraints are pronounced, soil organisms represent sensitive indicators of environmental change. Soil nematodes, due to their functional diversity encompassing bacterivores, fungivores, herbivores, omnivores, and predators, constitute effective bioindicators of soil health. We hypothesized that increasing continentality (thermal amplitude) would progressively reduce nematode diversity and functional complexity while altering CUE and metabolic footprints through community compositional shifts. A total of 130 soil samples were collected across three bioclimatic zones (island, coastal, and semi-continental) within the Arganeraie Biosphere Reserve, Morocco, and analyzed for nematode abundance, diversity, trophic structure, ecological indices, and functional traits. Nematode abundance and richness were significantly higher in the island zone compared to the coastal and semi-continental zones, while Shannon diversity did not differ significantly. The island zone exhibited a balanced trophic structure with higher proportions of bacteribores, fungivores, herbivores, and omnivores–predators, than the coastal and semi-continental zones. CUE values were consistently low (<0.5) across all zones, with the widest distribution in the island zone. Thermal amplitude was negatively associated with nematode biomass (R = −0.36), production (R = −0.27), and all trophic footprints, with herbivores showing the steepest decline (R = −0.51). Notably, total energy flux remained relatively stable despite reductions in diversity and trophic complexity, suggesting functional redundancy within dominant bacterivore guilds. These findings support the hypothesis that increasing continentality is associated with reduced nematode diversity and functional complexity, alongside altered carbon processing efficiency. This study underscores the value of integrating trophic, metabolic, and energetic approaches for assessing soil health vulnerability in Mediterranean agroecosystems under climate change. Full article

Root-knot nematode (Meloidogyne incognita) is a significant challenge in cucumber (Cucumis sativus L.) production under protected cultivation systems. This study aimed to evaluate the effects of four microbial biocontrol agents (Trichoderma asperellum, Beauveria bassiana, Fusarium proliferatum, and Bacillus mojavensis) on cucumber growth and root gall formation. Two greenhouse experiments (spring and summer 2023) were conducted using potted plants inoculated with 100 g of nematode-infected soil. All treatments improved seed germination compared with the untreated control, particularly B. mojavensis and T. asperellum. During vegetative growth, F. proliferatum and B. mojavensis produced higher biomass in the spring experiment, while T. asperellum enhanced root development. Treatment with T. asperellum reduced root galling by 45% in the spring and 31% in the summer experiment, although these differences were not statistically significant. In the chemotaxis assay, the different microbial biocontrol agents showed variation in the chemotaxis index (CI), ranging from 0 to 0.12 among treatments. Overall, microbial treatments mainly enhanced plant growth under nematode stress, while effects on root galling were limited. Full article

Plant-parasitic nematodes are a significant agricultural challenge, causing extensive damage to most essential crops globally. Predatory soil mites play a significant role as biocontrol agents against plant-parasitic nematodes and other pests in the soil ecosystem. A laboratory trial was conducted to evaluate the potential of the soil-dwelling predatory mite, Androlaelaps casalis (Berlese), to suppress the citrus nematode, Tylenchulus semipenetrans Cobb, and the root-knot nematode, Meloidogyne incognita (Kofoid and White). Our findings show that the predatory mite, A. casalis, completed development, oviposition, and survival when fed on second-stage juveniles of both T. semipenetrans (Ts-J2) and M. incognita (Mi-J2) and egg mass of M. incognita (Mi-EM) as prey in the lab in closed arenas at 30 °C, 55% RH. Survivorship was lower on (Mi-EM) than on (Ts-J2) and (Mi-J2). Individuals of A. casalis reared on (Ts-J2) and (Mi-J2) prey demonstrated enhanced performance as compared to (Mi-EM) prey. In addition, females laid a total of 48.72, 46.50, and 12.45 eggs on the three types of prey, respectively. Life table parameters showed that feeding of A. casalis on (Ts-J2) and (Mi-J2) led to the greatest intrinsic rate of increase per day (r_m = 0.286 and 0.279 females/female/day), while preying on (Mi-EM) offered the lowest reproduction rate (r_m = 0.092). In conclusion, this study provides novel insights into the biology and predatory performance of A. casalis under controlled laboratory conditions, providing foundational evidence that may inform the development of future sustainable nematode management strategies. Full article

The guava root-knot nematode (Meloidogyne enterolobii) is a highly aggressive species of root-knot nematode that is not manageable with currently existing nematode management methods. This study was conducted to evaluate the suppressive ability of winter cover crops against M. enterolobii. Eleven winter cover crops (rye, wheat, barley, triticale, oat, Austrian winter pea, crimson clover, balansa clover, hairy vetch, purple top turnip, and daikon radish) were evaluated against M. enterolobii in a growth room environment. Root-knot nematode-susceptible tomato (Solanum lycopersicum cv. Rutgers) was used as a control. Nematode reproduction on cover crops ranged from 1 to 501,373 eggs/g root, with oat supporting the least nematode reproduction and crimson clover supporting the greatest nematode reproduction. The crops significantly suppressing egg production on roots and second-stage juveniles in the soil relative to the control were oat, winter pea, wheat, barley, rye, and triticale. Hairy vetch, purple turnip, daikon radish, and crimson clover were good hosts, while balansa clover, wheat, winter pea, barley, rye, triticale and oat were poor or non-hosts, with the latter four crops producing substantial biomasses. Employment of these cover crops that suppress or do not support M. enterolobii reproduction while adding substantial biomass to the soil may lead to sustainable nematode management. Full article

Sudden death syndrome (SDS) and soybean cyst nematode (SCN) are major yield-limiting diseases in North American soybean production, with limited effective management options. Long-term soybean monoculture has been reported to suppress SDS and SCN, but the mechanisms, onset, and persistence of such suppression remain poorly understood. To study these mechanisms, a six-year field study (2018–2023) was conducted at two Ontario sites with contrasting disease histories: Chatham (conducive) and Essex (suppressive). We evaluated suppression development and resilience across soybean monoculture (SSSSSS) and corn–soybean rotations (SCSCSC/CSCSCS), using eight cultivars differing in SDS and SCN resistance across two maturity groups. In Chatham, disease index (DX) progressively declined under monoculture; the most susceptible cultivar, HS11RY07, declined from a mean DX of 89 to 43 by year six, with corresponding yield increases, and rotational yield advantages diminished. In Essex, introducing corn rotation increased SDS symptoms during soybean phases; monoculture yields became comparable to rotation in later years. Importantly, suppression developed without corresponding reductions in Fusarium virguliforme and SCN populations, which remained variable across years, suggesting that monoculture may disrupt pathogen effectiveness rather than eliminating it. This decoupling of pathogen abundance and disease severity is consistent with soil-mediated biological suppression; the microbial drivers are addressed in subsequent work. Full article

Background: Capillaria hepatica is a zoonotic nematode primarily infecting rodents. In humans, it causes hepatic capillariasis, a disease that resembles hepatitis. Rodents act as primary reservoirs and key amplifiers of transmission by ingesting the embryonated eggs in contaminated soil/food/water. The wet market is a potential hotspot for transmission through contaminated environments. Methods: We aimed to detect C. hepatica among wild rodents from three popular wet markets in Medan, Indonesia: Simpang Limun, Petisah, and Melati. Bait traps were placed near market stalls and nearby residences. Rodent species were identified based on morphology. Liver tissue was microscopically examined and further confirmed with PCR targeting the C. hepatica 18S rRNA gene. The spatial display was produced through a GIS approach. Results: From 150 rodents, the species captured were Rattus norvegicus (70.7%) and Rattus tanezumi (29.3%), with R. norvegicus as the most infected (95/106). Overall prevalence was 79.3%, with Petisah having the highest local prevalence (48/51). Positive rodents were found at market stalls and in nearby residential areas. Conclusions: We found a high prevalence of C. hepatica among wild rodents in the three wet markets in Medan, suggesting a potential threat of transmission to humans nearby. Full article

This study investigated the impact of matrixless silver nanoparticles (AgNPs) stabilized with Ag cations on Longidorus elongatus in substrates amended with a soil-enhancing fertilizer derived from sewage sludge, using a pot experiment with cucumber (Cucumis sativus L.) as the test plant. Seedling substrates were prepared by mixing granulated sewage sludge (A1, A2) with peat (P) at 25%, 50%, and 75% (mass fraction), while AgNPs were applied at a dose of 23.8 mL per pot. Plant performance was evaluated using biometric and physiological parameters, whereas nematode communities were extracted using the Baermann method and classified into trophic groups. The results demonstrated that substrate amendments significantly modified soil chemical properties, nematode abundance, and plant growth responses. AgNP exposure led to a substantial reduction in L. elongatus abundance, from 38–42 to 3–5 individuals per 100 cm³ relative to control substrates. The strongest reduction was observed under conditions of increased silver availability, indicating its significant role in limiting nematode population development. Overall, the combined application of sewage sludge-based fertilizers and AgNPs substantially influenced soil–plant–nematode interactions. These findings indicate that AgNPs may serve as an effective tool for regulating plant-parasitic nematodes within organically amended substrates, while simultaneously influencing plant growth and soil chemical dynamics. Full article

Root-knot nematodes (RKNs) are among the most destructive pests in protected watermelon production under continuous cropping systems. Although both pepper rotation and arbuscular mycorrhizal fungi (AMF) inoculation have shown potential for suppressing RKNs and promoting plant growth, their combined effects remain unclear. This study conducted greenhouse pot experiments using continuously cropped watermelon soil over two consecutive cycles. In the first cycle, chili pepper (Capsicum annuum) or watermelon (Citrullus lanatus) was planted, followed by watermelon cultivation in the second cycle with inoculation of Funneliformis mosseae or Glomus versiforme. Compared with continuous watermelon cropping, both rotation and AMF inoculation improved root vitality, osmotic regulation, antioxidant enzyme activities, and photosynthetic performance, thereby enhancing watermelon growth and resistance to RKNs. Among all treatments, chili pepper rotation combined with Glomus versiforme showed the best performance, increasing shoot fresh weight by 31% and reducing disease index (DI), gall index (GI), and egg mass index (EI) by 30.8%, 77.0%, and 57.1%, respectively. In addition, the populations of second-stage juveniles (J2) in soil and roots and adult females in roots decreased by 85.4%, 55.5%, and 50.8%, respectively. High-throughput sequencing results showed that the combined treatment enriched several potentially beneficial microbial taxa, including Ochrobactrum, Bacillus, Acinetobacter, and Delftia. In addition, it enriched predicted metabolic pathways that may be associated with plant growth promotion and stress tolerance. Overall, pepper rotation combined with Glomus versiforme inoculation represents a promising, environmentally friendly strategy for the management of watermelon root-knot nematode disease. Full article

Soil salinization threatens agricultural sustainability and food security, especially in arid and semi-arid regions, yet how salinity gradients reshape multi-trophic networks and their associations with functional genes remain unclear. We investigated soil bacteria, fungi, protists, nematodes, and the carbon-fixation gene cbbL along a natural salinity gradient (electrical conductivity: 1.2–12.4 mS cm⁻¹) in Karamay, Xinjiang. Salinity acted as a key environmental filter, significantly differentiating biotic communities into low- and high-salinity groups. Compared with bacteria and fungi, protists and nematodes exhibit higher sensitivity to salinity shifts from non-saline to slightly saline soils, with their Shannon diversity decreasing by 74.2% and 50.4%, respectively (p < 0.05). High salinity significantly reduced the connectivity, modularity, and robustness of soil multi-trophic co-occurrence networks, resulting in 36.8% fewer edges, 24.2% lower modularity, and diminished network robustness compared to low-salinity conditions. Crucially, salinity was associated with functional decoupling, defined as a shift in the dominant drivers of microbial carbon sequestration potential. At low salinity, biotic factors explained 94.2% of cbbL variation, whereas at high salinity abiotic factors governed 86.1%, as shown by GBM (Gradient Boosting Machine) analyses. Our findings indicate that protists and nematodes can act as early warning indicators for soil salinization, and biotic network complexity represents a core metric for assessing saline soil ecosystem stability. This study reveals salinization-induced biota–function decoupling patterns and provides insights for saline soil health assessment and biotic restoration. Full article

Root-knot nematodes of the genus Meloidogyne are among the most destructive endoparasitic nematodes due to their ability to infect a wide range of agriculturally important crops. In this context, nematode-trapping fungi have been widely recognized for their potential as biological control agents against plant-parasitic nematodes. In the present study, the nematode-trapping fungus Arthrobotrys thaumasius was isolated from roots soils of banana plants (Musa spp.) in the canton of Guayaquil, Guayas Province, Ecuador. Four strains were obtained and identified based on sequence analyses of molecular markers. In addition, the in vitro growth and sporulation of the isolates were evaluated, with cornmeal agar and oat agar proving to be the most suitable culture media. Three A. thaumasius isolates exhibited attraction and capture rates exceeding 65% against second-stage juveniles (J2) of Meloidogyne. This study represents the first report of the isolation and characterization of A. thaumasius in Ecuador and demonstrates that isolates HN-20, HN-21, and HN-24 have high potential as biological control agents, positioning them as promising candidates for the sustainable management of root-knot diseases caused by Meloidogyne spp. Full article