Entomopathogenic Nematodes in the Soil Environment: Distributions, Interactions and the Influence of Biotic and Abiotic Factors

Stuart, Robin J.; Barbercheck, Mary E.; Grewal, Parwinder S.

doi:10.1007/978-3-319-18266-7_4

Cited by 51 publications

(37 citation statements)

References 237 publications

(312 reference statements)

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“…It should be noted that the overall scarcity of the EPN might have been the main reason for the fact that we did not find any difference between the practices. At higher EPN densities these practices may have an effect and EPN scarcity could be simply explained by the general absence of insect hosts (Stuart et al 2015). Several studies have correlated the abundance of hosts with the abundance of EPN, but found contrasting findings.…”

Section: Discussionmentioning

confidence: 99%

“…Using SADIE analyses, we showed how EPN presence is associated in the field with the other trophic guilds (FLN, NF and microbial biomass). EPN are likely to suffer from predation and competition, which may significantly decrease their efficiency as biocontrol agents (Stuart et al, 2015). This is relevant for crop protection strategies that included EPN augmentation, as the response of FLN and NF populations will play a key role in the successful establishment of EPN populations.…”

Section: Discussionmentioning

confidence: 99%

“…In the agroecosystem, EPN are affected by various abiotic soil properties such as soil texture, moisture, temperature, and soil organic matter, which might be drastically altered by agricultural management practices, as well as biotic factors such as competitors and natural enemies (Stuart et al, 2006(Stuart et al, , 2015Lewis et al, 2015). Understanding these interactions is essential to reveal ways to enhance the potential of EPN as biocontrol agents in a particular soil type and agricultural scenario.…”

Section: Introductionmentioning

confidence: 99%

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Prevalence and activity of entomopathogenic nematodes and their antagonists in soils that are subject to different agricultural practices

Jaffuel

Mäder

Blanco-Pérez

et al. 2016

Agriculture, Ecosystems & Environment

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Agricultural management practices can modify soil properties in ways that may disrupt the abundance and activity of beneficial organisms in the soil. We assessed the impact of different soil management practices on entomopathogenic nematodes (EPN), which have great potential as biological control agents against root-feeding insects. Soils were sampled during spring and autumn 2013 in all 96 plots of a long-term Swiss field trial (DOK experiment) in a seven-year grass-clover ley rotation. By combining a traditional insect-baiting technique and real-time qPCR analyses, we identified and quantified over 20 soil-dwelling species (or genera). This allowed us to investigate how communities of natural EPN populations and their associated natural enemies and competitors are affected by (i) three crop types (wheat, maize and grass-clover ley) and (ii) farming systems, i.e. conventional, organic and biodynamic, which differed in fertilization, and pesticide use. We also determined the effects on soils' microbial biomass in terms of carbon (C mic) and nitrogen (N mic) and applied spatial distribution analysis (SADIE) to uncover patterns of aggregations and associations of the study organisms. Although manure based farming systems increased microbial biomass, the systems did not influence the presence of EPN or their antagonists. EPN were more abundant in winter-wheat plots after potatoes than in maize and grass-clover ley plots. Overall, very low numbers of EPN were recorded, implying that their natural presence would not be sufficient to have a satisfactory suppressive effect on root-feeding pests and the application of EPN would therefore be an appropriate measure to protect yields in case of root pest outbreaks.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Prevalence and activity of entomopathogenic nematodes and their antagonists in soils that are subject to different agricultural practices

Jaffuel

Mäder

Blanco-Pérez

et al. 2016

Agriculture, Ecosystems & Environment

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“…Their wide distribution in soils throughout the world (Adams et al, 2006 ) and the availability of commercial products (Lacey et al, 2015 ) make them excellent products in integrated pest management (IPM) programs or in organic production, both for augmentation or restoration of naturally occurring EPN (Campos-Herrera, 2015 ). However, their performance and activity is affected by biotic and abiotic factors, and hence, their efficacy depends on soil characteristics, agricultural management practices, and competition within the food web (Stuart et al, 2015 ).…”

Section: Introductionmentioning

confidence: 99%

Combined Field Inoculations of Pseudomonas Bacteria, Arbuscular Mycorrhizal Fungi, and Entomopathogenic Nematodes and their Effects on Wheat Performance

et al. 2017

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In agricultural ecosystems, pest insects, pathogens, and reduced soil fertility pose major challenges to crop productivity and are responsible for significant yield losses worldwide. Management of belowground pests and diseases remains particularly challenging due to the complex nature of the soil and the limited reach of conventional agrochemicals. Boosting the presence of beneficial rhizosphere organisms is a potentially sustainable alternative and may help to optimize crop health and productivity. Field application of single beneficial soil organisms has shown satisfactory results under optimal conditions. This might be further enhanced by combining multiple beneficial soil organisms, but this remains poorly investigated. Here, we inoculated wheat plots with combinations of three beneficial soil organisms that have different rhizosphere functions and studied their effects on crop performance. Plant beneficial Pseudomonas bacteria, arbuscular mycorrhizal fungi (AMF), and entomopathogenic nematodes (EPN), were inoculated individually or in combinations at seeding, and their effects on plant performance were evaluated throughout the season. We used traditional and molecular identification tools to monitor their persistence over the cropping season in augmented and control treatments, and to estimate the possible displacement of native populations. In three separate trials, beneficial soil organisms were successfully introduced into the native populations and readily survived the field conditions. Various Pseudomonas, mycorrhiza, and nematode treatments improved plant health and productivity, while their combinations provided no significant additive or synergistic benefits compared to when applied alone. EPN application temporarily displaced some of the native EPN, but had no significant long-term effect on the associated food web. The strongest positive effect on wheat survival was observed for Pseudomonas and AMF during a season with heavy natural infestation by the frit fly, Oscinella frit, a major pest of cereals. Hence, beneficial impacts differed between the beneficial soil organisms and were most evident for plants under biotic stress. Overall, our findings indicate that in wheat production under the test conditions the three beneficial soil organisms can establish nicely and are compatible, but their combined application provides no additional benefits. Further studies are required, also in other cropping systems, to fine-tune the functional interactions among beneficial soil organisms, crops, and the environment.

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“…3785. Conclusion 380Few naturally occurring EPNs have been shown to be significant regulators of pests, and 382 variables that modulate EPN services are generally poorly understood(Stuart et al, 2015; Lewis et al, 383 2015). By contrast, the EPNs that inhabit Florida citrus orchards are good targets for conservation tactics 384because they are especially virulent to Diaprepes root weevils on the central ridge where damage to citrus 385 by the insect is least (Duncan et al, 2003; Futch et al, 2005).…”

mentioning

confidence: 99%

Spatial relationships between entomopathogenic nematodes and nematophagous fungi in Florida citrus orchards

Pathak

Campos‐Herrera

El-Borai

et al. 2017

Journal of Invertebrate Pathology

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Relationships between entomopathogenic nematodes (EPNs), nematophagous fungi (NF) and soil physical and chemical properties were studied in a survey of 53 citrus orchards in central ridge and flatwoods ecoregions of Florida. Seven species of NF associated with nematodes were quantified directly using a real time qPCR assay. All nematophagous fungi studied except Arthrobotrys musiformis and Hirsutella rhossiliensis were frequently detected (24-56%) in both regions. Paecilomyces lilacinus and Gamsylella gephyropagumwere encountered more frequently in the flatwoods (P=0.03) and on the ridge (P=0.02), respectively. Redundancy analysis revealed seven abiotic and biotic factors as significantly related to the NF occurrence. Multiple regression of fungi on these variables explained 78%, 66%, 48%, 36%, 23% and 4% of the variation in Catenaria sp., A. musiformis, A. dactyloides, P. lilacinus, A. oligospora and G. gepharopagum, respectively. When the data from citrus were pooled with those reported previously from natural areas and subjected to principle component analysis, the first two principle components explained 43% of the variation in NF communities. The surveys (citrus vs natural areas) were discriminated by PC2 (P<0.001) and the ecoregion by PC1 (P<0.002), and all but one NF species were related (P<0.01) to one or both components. NF communities tended to have more species and greater diversity in the flatwoods, where EPN richness and diversity were the least. However, the strength of associations between individual EPN and NF species as measured by SADIE reflected the associations between each species and ground water depth, suggesting that ecoregion preferences affected the species associations. Within each ecoregion, significant relationships between the individual NF and EPN species measured by stepwise regression tended to be positive. The results did not support the hypothesis that NF modulate the spatial patterns of EPN species between or within these two ecoregions.

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Entomopathogenic Nematodes in the Soil Environment: Distributions, Interactions and the Influence of Biotic and Abiotic Factors

Cited by 51 publications

References 237 publications

Prevalence and activity of entomopathogenic nematodes and their antagonists in soils that are subject to different agricultural practices

Prevalence and activity of entomopathogenic nematodes and their antagonists in soils that are subject to different agricultural practices

Combined Field Inoculations of Pseudomonas Bacteria, Arbuscular Mycorrhizal Fungi, and Entomopathogenic Nematodes and their Effects on Wheat Performance

Spatial relationships between entomopathogenic nematodes and nematophagous fungi in Florida citrus orchards

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