Research

Jump to: Review

11 pages, 2067 KiB

Open AccessArticle

Nematodes Associated with Terrestrial Slugs in Mid-Atlantic (Delaware, USA) Soybean

by Brian Kunkel, William J. Cissel, John F. Tooker, Dana K. Howe, Dee R. Denver, Rory J. Mc Donnell and Ivan Hiltpold

Agronomy 2023, 13(3), 645; https://doi.org/10.3390/agronomy13030645 - 23 Feb 2023

Viewed by 1545

Abstract

Slugs are cryptic terrestrial pests that target a wide range of crops and are especially damaging to seedlings. Management of these invertebrates mostly relies on synthetic chemistry. These molecules can be efficient against slugs and snails but can be toxic to other organisms [...] Read more.

Slugs are cryptic terrestrial pests that target a wide range of crops and are especially damaging to seedlings. Management of these invertebrates mostly relies on synthetic chemistry. These molecules can be efficient against slugs and snails but can be toxic to other organisms (e.g., dogs) and harmful to the environment (e.g., leaching into surface and groundwater). The usage of pathogenic nematodes has been effective in several crops and European countries. A survey was conducted to investigate the presence of natural populations of malacopathogenic nematodes in soybean in the mid-Atlantic region. Slugs were sampled in nine fields across Delaware at various distances from the field edges (0 m, 5 m, 10 m, 15 m). Soil cover and soil type were also recorded. Invertebrates were brought back to the laboratory. Slugs were monitored for four weeks, and mortality was classified into one of three categories: (1) death with the presence of nematodes; (2) death with the presence of fungi; (3) death without the presence of nematodes or fungi. Nematodes associated with slugs were identified based on 18S rRNA sequencing. The distance from the field edge did not impact the number of trapped slugs and the incidence of slug death associated with the presence of nematodes. Overall, nematodes were collected from ca. 20% of the slug cadavers, and most have previously been associated with slugs (ca. 35% of deaths associated with fungi and ca. 45% not associated with nematodes or fungi). The number of captured slugs and slug death associated with the presence of nematodes were positively correlated with ground cover. Soil type impacted both the number of captured slugs and the presence of pathogenic nematodes. This survey provides a first insight into the natural populations of mollusk-associated nematodes in the mid-Atlantic region. This knowledge may contribute to implementing cultural practices favoring these natural enemies of slug pests. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

16 pages, 4889 KiB

Open AccessArticle

The Free-Living Nematodes as Indicators of the Soil Quality in Relation to the Clay Content, When Coffee Waste Is Applied

by Panagiotis Kekelis, Efimia M. Papatheodorou, Eleni Terpsidou, Maria Dimou, Vassilis Aschonitis and Nikolaos Monokrousos

Agronomy 2022, 12(11), 2702; https://doi.org/10.3390/agronomy12112702 - 01 Nov 2022

Cited by 6 | Viewed by 2128

Abstract

Coffee waste is an organic material that can potentially be used in agricultural systems as an organic amendment. This study investigated the effects of the application of three concentrations of coffee waste (1%, 2%, and 4% w/v), used as an [...] Read more.

Coffee waste is an organic material that can potentially be used in agricultural systems as an organic amendment. This study investigated the effects of the application of three concentrations of coffee waste (1%, 2%, and 4% w/v), used as an organic amendment, on soil free-living nematode communities, and in two different soil types (clay and sandy loam). Coffee waste incorporation did not appear to be toxic to the soil’s free-living nematodes; on the contrary, it favored the nematode populations; this increase was greater in the sandy loam soil type. Our results show that the abundance of the cp-1 bacteria-feeding nematodes can be used as an indicator of the soil’s enrichment or depletion phase. Panagrolaimus was the most promising genus to describe quality differentiations that occur in the soil system. Three months after coffee waste application, Panagrolaimus was found to be dominant in all coffee waste applications, indicating that the soil was in a phase of enrichment. Six months after the application, nematode community structure indices (enrichment and structure) showed that coffee waste was decomposed in the 1 and 2% treatments and that these systems were in a stage of nutrient depletion. In terms of agricultural practices, when a coffee waste dose is lesser than 4%, a second application is recommended before 6 months to avoid soil degradation. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

10 pages, 1384 KiB

Open AccessArticle

Using the Nematode, Steinernema carpocapsae, to Control Peachtree Borer (Synanthedon exitiosa): Optimization of Application Rates and Secondary Benefits in Control of Root-Feeding Weevils

by Colin Wong, Camila Oliveira-Hofman, Brett R. Blaauw, Dario Chavez, Ganpati Jagdale, Russell F. Mizell III and David Shapiro-Ilan

Agronomy 2022, 12(11), 2689; https://doi.org/10.3390/agronomy12112689 - 29 Oct 2022

Viewed by 1612

Abstract

The peachtree borer, Synanthedon exitiosa (Say) (Lepidoptera: Sesiidae), is a major pest of stone fruits including the peach Prunus persica (L.) Batsch. The entomopathogenic nematode, Steinernema carpocapsae, was previously shown to be an effective tool for controlling S. exitiosa. In orchards [...] Read more.

The peachtree borer, Synanthedon exitiosa (Say) (Lepidoptera: Sesiidae), is a major pest of stone fruits including the peach Prunus persica (L.) Batsch. The entomopathogenic nematode, Steinernema carpocapsae, was previously shown to be an effective tool for controlling S. exitiosa. In orchards where irrigation is not available, a sprayable gel (Barricade^®) can be used to maintain soil moisture which can facilitate nematode efficacy. However, rates of nematode and Barricade^® application had not been optimized for their maximum economic and biocontrol efficiency. Therefore, our objective was to compare rates of S. carpocapsae and Barricade^® in field trials. Nematodes were tested at per-tree application rates of 1.5 million, 1 million and 0.5 million infective juveniles. The sprayable gel was used at two rates, 4% and 2%. A reduction in the used nematodes from 1.5 million to 0.5 million per tree showed no difference in efficacy. Similarly, using the gel at half rate also did not impact the efficacy, and treatments containing nematodes controlled the S. exitiosa better than the chlorpyrifos control in several of the tests (p < 0.05). As an added benefit, the nematode treatments were also able to reduce the prevalence of weevil (Coleoptera: Curculionidae) populations as secondary pests of the peach trees. The lower rates of grower inputs will reduce costs, making the nematode biocontrol of the peachtree borer more likely to be adopted by commercial growers of peach. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

14 pages, 2122 KiB

Open AccessArticle

Investigation of Indigenous Entomopathogenic Nematodes in Guangxi and Its Biological Control of Spodoptera frugiperda

by Ailing Wang, Ming Fang, Jie Sun, Xianqin Wei and Weibin Ruan

Agronomy 2022, 12(10), 2536; https://doi.org/10.3390/agronomy12102536 - 17 Oct 2022

Cited by 1 | Viewed by 1643

Abstract

Spodoptera frugiperda has caused serious economic damage to various crops. Entomopathogenic nematodes (EPNs) can be used as biological control agents for many pests, including lepidopteran insects. In this study, 218 soil samples were collected from 46 sites in Guangxi, and EPNs were detected [...] Read more.

Spodoptera frugiperda has caused serious economic damage to various crops. Entomopathogenic nematodes (EPNs) can be used as biological control agents for many pests, including lepidopteran insects. In this study, 218 soil samples were collected from 46 sites in Guangxi, and EPNs were detected in 15 samples. The ITS region of the rDNA gene was used for the molecular identification of isolated nematodes. In total, four and eleven identified populations belonged to Heterorhabditis and Oscheius, respectively. A series of bioassays were conducted to examine the virulence of EPN isolates from Guangxi to control the larvae and pupae of S. frugiperda. The mortality of the third-instar larvae caused by EPNs was concentration dependent. The same dose of EPNs was used to control the third and sixth-instar larvae of S. frugiperda, and the virulence was lower in the sixth-instar larvae. S. frugiperda pupae were treated with different EPNs strains, and the adult eclosion rate of the treated group was significantly lower than that of the sterile water control group (93.3%). Therefore, EPNs could significantly inhibit the eclosion of S. frugiperda pupae. This study provides important information for the biological control of S. frugiperda with EPNs. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

17 pages, 2242 KiB

Open AccessArticle

Arthropod Community Responses Reveal Potential Predators and Prey of Entomopathogenic Nematodes in a Citrus Orchard

by Alexandros Dritsoulas, Sheng-Yen Wu, Homan Regmi and Larry W. Duncan

Agronomy 2022, 12(10), 2502; https://doi.org/10.3390/agronomy12102502 - 13 Oct 2022

Cited by 1 | Viewed by 1507

Abstract

The contributions of soil arthropods to entomopathogenic nematode (EPN) food webs are mainly studied in artificial conditions. We investigated changes in arthropod communities in a citrus orchard following soil inundation with Steinernema feltiae or Heterorhabditis bacteriophora. We hypothesized that arthropod taxa, which [...] Read more.

The contributions of soil arthropods to entomopathogenic nematode (EPN) food webs are mainly studied in artificial conditions. We investigated changes in arthropod communities in a citrus orchard following soil inundation with Steinernema feltiae or Heterorhabditis bacteriophora. We hypothesized that arthropod taxa, which decline or increase in response to EPN augmentation, represent potential prey or predators of EPN, respectively. Soil was sampled periodically after nematodes were applied, DNA was extracted from organisms recovered by sucrose centrifugation, libraries were prepared, and the ITS2 and CO1 genes were sequenced using Illumina protocol. Species from 107 microarthropod (mites and collembola) families and 121 insect families were identified. Amplicon sequence variant (ASV) reads for H. bacteriophora were less than 10% of those for S. feltiae three days after inundation, whereas microarthropod ASVs were double in plots with H. bacteriophora compared to those with S. feltiae. Significantly fewer microarthropod and insect reads in S. feltiae compared to untreated plots suggest the possibility that S. feltiae preyed on mites and Collembola in addition to insects. The responses over time of the individual microarthropod species (MOTU) suggest that regulation (up or down) of these EPN resulted from a cumulative response by many species, rather than by a few key species. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

17 pages, 1364 KiB

Open AccessFeature PaperArticle

The Invasion and Long Naturalization of Solanum elaeagnifolium affects the Soil Nematode Community: Evidence from a Comparative Study

by Maria Karmezi, Nikos Krigas and Maria D. Argyropoulou

Agronomy 2022, 12(10), 2346; https://doi.org/10.3390/agronomy12102346 - 29 Sep 2022

Cited by 4 | Viewed by 1534

Abstract

To date, the effects of invasive plants on soil communities and the concomitant interactions thereof have been the subject of ever-growing concern. Solanum elaeagnifolium (S) is a noxious invasive weed originating from south-central America, which has been recognized as a serious threat around [...] Read more.

To date, the effects of invasive plants on soil communities and the concomitant interactions thereof have been the subject of ever-growing concern. Solanum elaeagnifolium (S) is a noxious invasive weed originating from south-central America, which has been recognized as a serious threat around the Mediterranean basin and worldwide. Herein, we compared soil nematode communities in the rhizospheres of (S), against those of its native antagonist Cichorium intybus (C), in sites where these two ruderal plants coexist (“species” effect—hereafter “sp”). These sites differed regarding the time after the initial invasion of (S) and were regarded as recently and historically invaded (10 years and 70 years after invasion; “year” effect—hereafter “yr”). Neither “sp” nor “yr” affected total nematode abundance and nematode functional indices. Diversity was lower in (S) and was reduced even more with time after invasion in both plant species. Plant parasites decreased significantly from S–10yr to S–70yr, i.e., over time after invasion, while predators were fewer in (C). Distinct nematode communities in terms of genera structure were formed under the two plant species and these were significantly affected by the time after (S) invasion. Differences between these communities related to loss of genera but also to changes in the abundance of common ones, such as Acrobeloides and Pratylenchus. Our results showed that the responses of the examined soil communities to the invasion of (S) are not straightforward and cannot be easily explained on the basis of existing theories. However, the first-time results furnished herein may be useful to integrated management strategies in the future. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

10 pages, 674 KiB

Open AccessCommunication

Reproduction of Soybean Cyst Nematode Populations on Field Pennycress, Henbit, and Purple Deadnettle Weed Hosts

by Pawan Basnet, Sharon A. Clay and Emmanuel Byamukama

Agronomy 2022, 12(9), 2027; https://doi.org/10.3390/agronomy12092027 - 26 Aug 2022

Cited by 3 | Viewed by 1503

Abstract

Several weeds serve as alternative soybean cyst nematode (SCN) hosts. Still, the relative reproductive capacity of SCN HG types (Heterodera glycines type) on weed hosts relative to soybean is not well understood. This study examined the reproduction of three South Dakota endemic [...] Read more.

Several weeds serve as alternative soybean cyst nematode (SCN) hosts. Still, the relative reproductive capacity of SCN HG types (Heterodera glycines type) on weed hosts relative to soybean is not well understood. This study examined the reproduction of three South Dakota endemic SCN populations—PSCN-1 (HG 0), PSCN-2 (HG 2.5.7), and PSCN-3 (HG 7)—on purple deadnettle, field pennycress, and henbit. The Relative Female Index (RFI) was calculated to compare SCN reproduction relative to the susceptible soybean check. Weed hosts, HG types, and their interactions influenced SCN reproduction. Henbit (RFI = 51.8) and purple deadnettle (RFI = 47.6) roots had a similar high RFI, whereas field pennycress (RFI = 23.04) had a lower RFI. Similarly, SCN populations PSCN-1 and PSCN-3 had a similar RFI of 36.9 and 37.2, respectively, while the population PSCN-2 had a higher RFI of 44.9 across weed hosts. A significant interaction between PSCN-1 and purple deadnettle was observed where the RFI was the highest (RFI = 53.3). These results indicate that these weed hosts support endemic SCN populations, and the HG type influenced reproductive success, further complicating SCN management. Hence, SCN presents a significant challenge in the new prospect of incorporating field pennycress host as an oilseed cover crop in the Midwest’s corn–soybean production system. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

13 pages, 2212 KiB

Open AccessArticle

Steinernema australe Enhanced Its Efficacy against Aegorhinus nodipennis (Coleoptera: Curculionidae) Larvae in Berry Orchards after an Artificial Selection Process

by Patricia D. Navarro, Rubén Palma-Millanao, Ricardo Ceballos and Almendra J. Monje

Agronomy 2022, 12(5), 1128; https://doi.org/10.3390/agronomy12051128 - 07 May 2022

Cited by 2 | Viewed by 1545

Abstract

The entomopathogenic nematode (EPN) Steinernema australe was isolated from Isla Santa Magdalena in Chile and identified as a good alternative for controlling Aegorhinus nodipennis (Coleoptera: Curculionidae) larvae. This weevil is native to the south of Chile and some regions in Argentina, causing the [...] Read more.

The entomopathogenic nematode (EPN) Steinernema australe was isolated from Isla Santa Magdalena in Chile and identified as a good alternative for controlling Aegorhinus nodipennis (Coleoptera: Curculionidae) larvae. This weevil is native to the south of Chile and some regions in Argentina, causing the decline and ultimate death of plants in berry orchards. The major problem brought about by the weevil is caused by the larvae, which spend between nine and eleven months below ground, feeding inside the roots of the plants. This study seeks to increase S. australe’s efficacy through an artificial selection process using an odor stimulus. We selected infective juveniles (IJs) that followed the stimulus in order to reach larvae at a depth of 30 cm to achieve this objective. Larvae infected with selected IJs and IJs from the original stock were compared under laboratory, greenhouse, and field conditions. The results showed a 20% increase in the efficacy of selected IJs compared with IJs from the original stock. We observed a higher proportion of selected IJs that reached the larvae faster during the first four days post-application. Moreover, larvae treated with selected IJs were depleted, with a mix of nematode stages emerging from the cadaver. Finally, a potential trade-off with regard to the recycling of nematodes into the soil is proposed. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

17 pages, 1034 KiB

Open AccessArticle

Flux of Root-Derived Carbon into the Nematode Micro-Food Web: A Comparison of Grassland and Agroforest

by Christin Hemmerling, Zhipeng Li, Lingling Shi, Johanna Pausch and Liliane Ruess

Agronomy 2022, 12(4), 976; https://doi.org/10.3390/agronomy12040976 - 18 Apr 2022

Cited by 1 | Viewed by 1987

Abstract

Carbon (C) cycling is crucial to agroecosystem functioning. Important determinants for the belowground C flow are soil food webs, with microorganisms and microfaunal grazers, i.e., nematodes, as key biota. The present study investigates the incorporation of plant-derived C into the nematode micro-food web [...] Read more.

Carbon (C) cycling is crucial to agroecosystem functioning. Important determinants for the belowground C flow are soil food webs, with microorganisms and microfaunal grazers, i.e., nematodes, as key biota. The present study investigates the incorporation of plant-derived C into the nematode micro-food web under two different cropping systems, grassland (ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.)) and agroforest (willow (Salix schwerinii Wolf and Salix viminalis L)). To quantify the C flux from the plant into the soil micro-food web, grass and willow were pulse-labeled with ¹³CO₂ and the incorporation of ¹³C into the nematode trophic groups was monitored 3, 7, 14 and 28 days after labeling. The natural stable isotope signals (¹³C/¹²C, ¹⁵N/¹⁴N) were analyzed to determine the structure of the nematode micro-food web. The natural isotopic δ¹⁵N signal revealed different trophic levels for omnivores and predators in grassland and agroforest soils. The incorporation of plant C into nematode tissue was detectable three days after ¹³CO₂ labeling with the highest and fastest C allocation in plant feeders in grassland, and in fungal feeders in agroforest soil. C flux dynamics between the aboveground vegetation and belowground micro-food web varied with cropping system. This demonstrates that crop-specific translocation of C affects the multitrophic interactions in the root environment, which in turn can alter soil nutrient cycling. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

16 pages, 2724 KiB

Open AccessArticle

Current Utility of Arbuscular Mycorrhizal Fungi and Hydroxyapatite Nanoparticles in Suppression of Tomato Root-Knot Nematode

by Saad Alamri, Nivien A. Nafady, Atef M. El-Sagheer, Mohamed Abd El-Aal, Yasser S. Mostafa, Mohamed Hashem and Elhagag A. Hassan

Agronomy 2022, 12(3), 671; https://doi.org/10.3390/agronomy12030671 - 10 Mar 2022

Cited by 7 | Viewed by 2869

Abstract

Effective biosafe management strategies are used to decrease world crop damage produced by plant-parasitic nematodes. This study evaluated the efficiency of hydroxyapatite nanoparticles (n-HAP) and mycorrhizal fungi to control the Meloidogyne incognita infecting tomato plants. Application of n-HAP significantly increased the juveniles’ mortality [...] Read more.

Effective biosafe management strategies are used to decrease world crop damage produced by plant-parasitic nematodes. This study evaluated the efficiency of hydroxyapatite nanoparticles (n-HAP) and mycorrhizal fungi to control the Meloidogyne incognita infecting tomato plants. Application of n-HAP significantly increased the juveniles’ mortality (195.67%) and egg hatching inhibition percentage (80.71%) compared to the untreated control, in vitro. Mycorrhizal and/or n-HAP treatments increased the plant growth parameters (root and shoot length, dry weight, and leaf area) and reduced the negative consequence of nematode infection. This may be due to indirect mechanisms through increasing plant nutrient uptake efficiency and increasing the internal plant resistance against nematode infection. In dual-treated plants, phosphorus, nitrogen, and calcium content recorded the highest value in the nematode-infected plants. Whereas the dual inoculation significantly increased mineral contents in tomato plants compared with control, this may induce the strength of the cell wall of the epidermal layer and cortex and consequently increase the plant resistance against nematode infection. Our results revealed that the application of the plant resistance-stimulants enhanced the plant growth parameters and internal nutrient content and reduced the nematode’s criteria. Consequently, the internal plant resistance against nematode infection was induced. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

11 pages, 1531 KiB

Open AccessArticle

Lethality of Phasmarhabditis spp. (P. hermaphrodita, P. californica, and P. papillosa) Nematodes to the Grey Field Slug Deroceras reticulatum on Canna Lilies in a Lath House

by Jacob Schurkman, Christine Dodge, Rory Mc Donnell, Irma Tandingan De Ley and Adler R. Dillman

Agronomy 2022, 12(1), 20; https://doi.org/10.3390/agronomy12010020 - 23 Dec 2021

Cited by 6 | Viewed by 3252

Abstract

The grey field slug, Deroceras reticulatum, is an agricultural pest causing damage to a wide variety of crops each year. The nematode Phasmarhabditis hermaphrodita has been shown to effectively kill this slug in field-simulated conditions, leading to its widespread use as a [...] Read more.

The grey field slug, Deroceras reticulatum, is an agricultural pest causing damage to a wide variety of crops each year. The nematode Phasmarhabditis hermaphrodita has been shown to effectively kill this slug in field-simulated conditions, leading to its widespread use as a biological control agent in Europe. However, recently discovered isolates of Phasmarhabditis from California have not been tested in a field-simulated environment. The lethality of three local isolates of Phasmarhabditis (P. hermaphrodita, P. californica, & P. papillosa) as well as the molluscicide Sluggo Plus^® was assessed on D. reticulatum in a lath house. Remaining leaf area on Canna lilies and slug mortality were recorded after 3 weeks of exposure to treatments. Local isolates efficiently killed D. reticulatum and protection from leaf damage was attained by treatment with P. papillosa. Further experimentation is required to assess plant protection afforded by Phasmarhabditis as plants in some trials may have been in poor health. The three tested Phasmarhabditis isolates are reasonable candidates for biological control within the United States but additional information, particularly on the lethality to non-target gastropods, is needed before an informed decision on their use can be made. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

Review

Jump to: Research

27 pages, 2686 KiB

Open AccessEditor’s ChoiceReview

Soil Nematodes as a Means of Conservation of Soil Predatory Mites for Biocontrol

by Diana Rueda-Ramírez, Eric Palevsky and Liliane Ruess

Agronomy 2023, 13(1), 32; https://doi.org/10.3390/agronomy13010032 - 22 Dec 2022

Cited by 6 | Viewed by 4530

Abstract

Numerous lab and field studies have reported the potential of soil predatory mites for the biological control of plant-parasitic nematodes and arthropods pests. Most of these studies have utilized biocontrol agents in augmentative releases, essentially controlling the pest with the released predators. While [...] Read more.

Numerous lab and field studies have reported the potential of soil predatory mites for the biological control of plant-parasitic nematodes and arthropods pests. Most of these studies have utilized biocontrol agents in augmentative releases, essentially controlling the pest with the released predators. While this may be a valid approach, we hypothesize that conservation of soil mite predators with available, suitable, and accessible free-living nematodes as prey, will provide better agricultural ecosystem performance and long-range sustainability. In this manuscript, we review the relevant studies on soil predatory mite–nematode interactions and highlight their potential for conservation biological control of soil-borne pests. Additionally, we emphasize the importance of implementing environmentally sound soil management practices for the sustainability and conservation of functional soil food webs. Full article

(This article belongs to the Special Issue Nematodes: Drivers of Agricultural Ecosystem Performance)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Nematodes: Drivers of Agricultural Ecosystem Performance

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (12 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI