Nematobacterial Complexes and Insect Hosts: Different Weapons for the Same War

Entomopathogenic nematodes (EPNs) are widely used as biological control agents against insect pests, the efficacy of these organisms strongly depends on the balance between the parasitic strategies and the immune response of the host. This review summarizes roles and relationships between insect hosts and two well-known EPN species, Steinernema feltiae and Steinernema carpocapsae and outlines the main mechanisms of immune recognition and defense of insects. Analyzing information and findings about these EPNs, it is clear that these two species use shared immunosuppression strategies, mainly mediated by their symbiotic bacteria, but there are differences in both the mechanism of evasion and interference of the two nematodes with the insect host immune pathways. Based on published data, S. feltiae takes advantage of the cross reaction between its body surface and some host functional proteins, to inhibit defensive processes; otherwise, secretion/excretion products from S. carpocapsae seem to be the main nematode components responsible for the host immunosuppression.

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Allelopathy: a possible mechanism of suppression of plant-parasitic nematodes by entomopathogenic nematodes

Nematology ◽

10.1163/156854199508766 ◽

1999 ◽

Vol 1 (7) ◽

pp. 735-743 ◽

Cited By ~ 32

Author(s):

Parwinder S. Grewal ◽

Edwin E. Lewis ◽

Sudha Venkatachari

Keyword(s):

Meloidogyne Incognita ◽

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Steinernema Feltiae ◽

Symbiotic Bacteria ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Tomato Roots ◽

Xenorhabdus Nematophilus ◽

Plant Parasitic

Abstract A possible mechanism of suppression of a plant-parasitic nematode Meloidogyne incognita by entomopathogenic nematodes is described. Heat-killed entomopathogenic nematodes Steinernema feltiae and S. riobrave temporarily suppressed penetration of the root-knot nematode M. incognita into tomato roots, but live nematodes had no effect. Infective juvenile M. incognita were repelled from all entomopathogenic nematode treatments that included their symbiotic bacteria. They were repelled by Galleria mellonella cadavers infected with S. carpocapsae, S. feltiae, and S. riobrave and from cell-free culture filtrates of the symbiotic bacteria Xenorhabdus nematophilus, X. bovienii, and Xenorhabdus sp. "R" from the three nematode species, respectively. Cell-free filtrates from all three Xenorhabdus spp. were toxic to M. incognita infective juveniles causing 98-100% mortality at 15% concentration. Cell-free filtrate of Xenorhabdus sp. "R" also reduced the hatch of M. incognita eggs. Application of formulated bacterial cell-free filtrates temporarily suppressed M. incognita penetration into tomato roots in a greenhouse trial. The short-term effects of cell-free bacterial filtrates, namely toxicity and repellency, were almost entirely due to ammonium. These results demonstrate allelopathic interactions between plant-parasitic nematodes, entomopathogenic nematodes and their symbiotic bacteria. The likely role of allelopathy in the suppression of plant-parasitic nematodes by innundative applications of entomopathogenic nematodes is discussed. Allelopathie: Ein moglicher Mechanismus zur Unterdruckung pflanzenparasitarer Nematoden durch insektenpathogene Nematoden - Es wird ein moglicher Mechanismus zur Unterdruckung des pflanzenparasitaren Nematoden Meloidogyne incognita durch insektenpathogene Nematoden beschrieben. Durch Hitze abgetotete insektenpathogene Nematoden Steinernema feltiae und S. riobrave underdruckten das Eindringen des Wurzelgallenalchens M. incognita in Tomatenwurzeln, lebende Nematoden hatten keine Wirkung. Infektionsjuvenile von M. incognita wurden von allen Behandlungen mit insektenpathogenen Nematoden abgestossen, die auch die symbiontischen Bakterien einschlossen. Sie wurden durch die Kadaver von Galleria mellonella abgestossen, die mit S. carpocapsae, S. feltiae und S. riobrave infiziert waren sowie durch zellfreie Kultursubstrate der symbiontischen Bakterien Xenorhabdus nematophilus, X. bovienii und Xenorhabdus sp. "R" aus den drei genannten Nematodenarten. Zellfreie Kultursubstrate von allen drei Xenorhabdus spp. waren giftig fur die Infektionsjuvenilen von M. incognita und verursachten in einer Konzentration von 15% Abtotungsraten von 98-100%. Zellfreie Kultursubstrate von Xenorhabdus sp. "R" vermiderten ausserdem das Schlupfen von M. incognita-Eiern. In einem Gewachshausversuch unterdruckten formulierte zellfreie Bakterienfiltrate vorubergehend das Eindringen von M. incognita in Tomatenwurzeln. Die Kurzzeitwirkungen von zellfreien Bakterien filtraten, namentlich Giftigkeit und Abstossung, waren nahezu ganz bedingt durch Ammoniak. Diese Ergebnisse zeigen das Vorhandensein von allelopathischen Wechselwirkungen zwischen pflanzenparasitaren Nematoden, insektenpathogenen Nematoden und deren symbiontischen Bakterien. Die wahrscheinliche Rolle von Allelopathie bei der Unterdruckung pflanzenparasitarer Nematoden durch eine Massenanwendung insektenpathogener Nematoden wird diskutiert.

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Laboratory bioassays of virulence of entomopathogenic nematodes against soil-inhabiting stages of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae)

Nematology ◽

10.1163/156854103322683256 ◽

2003 ◽

Vol 5 (4) ◽

pp. 539-547 ◽

Cited By ~ 21

Author(s):

Dammini Premachandra ◽

Christian Borgemeister ◽

Oliver Berndt ◽

Ralf-Udo Ehlers ◽

Hans-Michael Poehling

Keyword(s):

Entomopathogenic Nematodes ◽

Frankliniella Occidentalis ◽

Western Flower Thrips ◽

Steinernema Carpocapsae ◽

Steinernema Feltiae ◽

Flower Thrips ◽

Laboratory Trial ◽

Dose Response Study ◽

First Time ◽

Laboratory Bioassays

Abstract The efficacy of entomopathogenic nematodes (EPN) was evaluated in a laboratory trial against soil-dwelling stages, late second instar larvae and pupal stages of western flower thrips (WFT), Frankliniella occidentalis Pergande. Among the six EPN strains assessed for the first time, Steinernema feltiae (Nemaplus®) and Heterorhabditis bacteriophora (HD01) caused 65 and 59% mortality, respectively. Steinernema carpocapsae (Agriotos) and S. arenarium (Anomali) caused moderate mortality (40-45%) while Steinernema spp. (Morocco) and H. bacteriophora (Nematop®) had little effect. In a dose response study with concentrations of 100, 400 and 800 infective juveniles (IJ) per cm2 soil of H. bacteriophora (HK3), S. feltiae (Nemaplus®) and H. bacteriophora (HD01), mortality increased only up to 400 IJ cm-2. The rate of infectivity of H. bacteriophora (HK3) and S. feltiae (Nemaplus®) indicated that both strains could survive at least 6 days in the soil and infect WFT immature stages.

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Biological activity of entomopathogenic nematodes on Anastrepha fraterculus (Diptera: Tephritidae)

Bioscience Journal ◽

10.14393/bj-v37n0a2021-53895 ◽

2021 ◽

Vol 37 ◽

pp. e37047

Author(s):

Sandra Mara Chaneiko ◽

Andressa Lima de Brida ◽

Daniel Bernardi ◽

Luis Garrigós Leite ◽

Flávio Roberto Mello Garcia

Keyword(s):

Biological Control ◽

Biological Activity ◽

Maximum Concentration ◽

Entomopathogenic Nematodes ◽

Steinernema Carpocapsae ◽

Steinernema Feltiae ◽

Anastrepha Fraterculus ◽

Pupal Mortality ◽

Control Tool

Anastrepha fraterculus (Wiedemann) is one of the main pests of fruit farming, and entomopathogenic nematodes (EPNs) represent an important control tool of this species. Thus, the objective of this study was to evaluate the biological activity of different isolate against A. fraterculus larvae and adults. Bioassays were performed using a suspension of three isolates of Heterorhabditis amazonensis IBCB 24, Steinernema carpocapsae IBCB 02 and Steinernema feltiae IBCB 47 at six concentrations (control - without nematodes), 50, 150, 300, 500, 1000 and 1500 infective juveniles (IJs)/mL of water per 3º instar larvae. It was verified the susceptibility of larvae of A. fraterculus to isolates of EPNs and a significant increase of the pupal mortality in the function of the concentration of IJs inoculated by larva (above 75%). After the dissection of pupae and adults of A. fraterculus from infected larvae, the concentration of 1500 IJs/mL of EPNs provided the highest rate of multiplication of IJs by insect, equating to maximum concentration tested 1500 IJs/mL. Adults of A. fraterculus from larvae infected with EPNs longevity of five days, being less than adults from uninfected larvae by IJs (135 days). H. amazonensis IBCB 24, S. carpocapsae IBCB 02, and S. feltiae IBCB 47 proved to be promising as agents of biological control of A. fraterculus.

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A survey of entomopathogenic nematodes and their symbiotic bacteria in agricultural areas of northern Thailand

Journal of Helminthology ◽

10.1017/s0022149x20000735 ◽

2020 ◽

Vol 94 ◽

Author(s):

J. Ardpairin ◽

P. Muangpat ◽

S. Sonpom ◽

A. Dumidae ◽

C. Subkrasae ◽

...

Keyword(s):

Entomopathogenic Nematodes ◽

Biocontrol Agent ◽

Insect Pests ◽

Soil Samples ◽

Symbiotic Bacteria ◽

Soil Parameters ◽

Field Crops ◽

Indian Strain ◽

Agricultural Areas ◽

28S Ribosomal Dna

Abstract Entomopathogenic nematodes (EPNs) Steinernema and Heterorhabditis and their symbiotic bacteria, Xenorhabdus and Photorhabdus, have been successfully used for the control of insect pests. The objectives of this study were to survey the EPNs and symbiotic bacteria in the agricultural areas of the Phitsanulok province, Thailand, and to study the association between the soil parameters and presence of EPNs. We collected 200 soil samples from 40 soil sites in agricultural areas (field crops, horticulture crops and forest). The prevalence of EPNs was 8.0% (16/200). Fifteen of the EPN isolates were molecularly identified (based on 28S ribosomal DNA and internal transcribed spacer regions) as Steinernema siamkayai. Seven isolates of Xenorhabdus stockiae were identified using recombinase A sequencing. Phylogenetic analysis revealed that all the Steinernema and Xenorhabdus isolates were closely related to S. siamkayai (Indian strain) and X. stockiae (Thai strain), respectively. Significantly more EPNs were recovered from loam than from clay. Although the association between soil parameters (pH, temperature and moisture) and the presence of EPNs was not statistically significant, the elevation levels of the soil sites with and without EPNs were found to be different. Moreover, statistical comparisons between the agricultural areas revealed no significant differences. Therefore, we concluded that S. siamkayai is associated with X. stockiae in agricultural areas and that there is no association between the soil parameters of agricultural areas and presence of EPNs, except for soil texture and the elevation. Steinernema siamkayai may be applied as a biocontrol agent in agricultural areas.

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Effect of recycling temperature on the infectivity of entomopathogenic nematodes

Canadian Journal of Zoology ◽

10.1139/z97-849 ◽

1997 ◽

Vol 75 (12) ◽

pp. 2137-2141 ◽

Cited By ~ 6

Author(s):

Ganpat B. Jagdale ◽

Roger Gordon

Keyword(s):

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Steinernema Carpocapsae ◽

Steinernema Feltiae ◽

Wax Moth

Four strains of entomopathogenic nematodes were recycled in vivo for 2 years at temperatures ranging from 10 to 25 °C, then the infectivity of their infective juveniles was compared. Infectivity was examined by measuring LC50 values for wax moth (Galleria mellonella) larvae at bioassay temperatures ranging from 5 to 25 °C. Of the four strains examined, only the Umeå and NF strains of Steinernema feltiae that had been recycled at 10 °C infected and killed the insects at a bioassay temperature of 5 °C. The Steinernema carpocapsae All and Steinernema riobravis TX strains were infective at 10 °C only when the recycling temperature was ≤ 20 °C. The infectivity of the two strains of S. feltiae at 10 or 15 °C was compromised by propagating them at higher temperatures (20–25 °C). The Umeå strain of S. feltiae displayed an impaired capacity to infect hosts at higher temperatures (20–25 °C) when recycled at lower (≤ 15 °C) temperatures. The capacity of these nematodes to adjust to different recycling temperatures is discussed in relation to their infectivity in different field situations.

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A survey of entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae (Nematoda: Rhabditida) in the north-west of Iran

Nematology ◽

10.1163/156854108x398453 ◽

2009 ◽

Vol 11 (1) ◽

pp. 107-116 ◽

Cited By ~ 23

Author(s):

Naser Eivazian Kary ◽

Gholamreza Niknam ◽

Seyed Abolgasem Mohammadi ◽

Christine Griffin ◽

Mohammad Moghaddam

Keyword(s):

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Heterorhabditis Bacteriophora ◽

Common Species ◽

Soil Samples ◽

Steinernema Carpocapsae ◽

Steinernema Feltiae ◽

North West ◽

The North ◽

First Time

AbstractDuring 2002-2004, a survey of entomopathogenic nematodes was conducted for the first time in Iran throughout the three provinces in the north-west of the country. Soil samples were tested for the presence of steinernematid and heterorhabditid nematodes by baiting with Galleria mellonella larvae. Of the 833 soil samples studied 27 were positive for entomopathogenic nematodes (3.2%), with 17 (2.0%) containing Heterorhabditis and ten (1.2%) Steinernema isolates. Morphological and molecular studies were carried out to characterise isolates. The Heterorhabditis isolates were identified as Heterorhabditis bacteriophora and Steinernema as Steinernema carpocapsae, S. bicornutum and S. feltiae. Heterorhabditis bacteriophora was the most common species, which was isolated from 17 sites across the three provinces. Steinernema feltiae was the most common species of Steinernema, which was isolated from eight sites but in only two provinces. Steinernema carpocapsae and S. bicornutum were each isolated from only one site. Steinernema spp. were isolated mainly from orchards and grasslands but Heterorhabditis was isolated mainly from grasslands and alfalfa fields.

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A survey investigating the diversity and distribution of entomopathogenic nematodes in the UK and the first confirmed UK record of Steinernema carpocapsae

Nematology ◽

10.1163/15685411-00003180 ◽

2018 ◽

Vol 20 (9) ◽

pp. 851-858 ◽

Cited By ~ 1

Author(s):

Cassandra Edmunds ◽

Rory J. Post ◽

Craig S. Wilding ◽

Robbie Rae

Keyword(s):

Biological Control ◽

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Soil Samples ◽

Steinernema Carpocapsae ◽

Biological Control Agents ◽

Diverse Range ◽

The World ◽

The Uk ◽

Insect Parasites

Summary Entomopathogenic nematodes (EPN) of the families Steinernematidae and Heterorhabditidae are lethal insect parasites that have been commercialised as biological control agents. EPN have been isolated from across the world but it has been more than 20 years since the last survey of the UK, and species like Steinernema carpocapsae have never been found here and positively identified through molecular biology. We collected 518 soil samples from a diverse range of habitats across the UK and baited them with Galleria mellonella to isolate EPN. Dead G. mellonella were placed in White traps and emergent EPN underwent DNA barcoding analyses. From the 518 samples, 3.5% were positive for EPN. No Heterorhabditis species were found, but seven isolates of S. glaseri, one isolate of S. feltiae, eight isolates of S. affine and two isolates of S. carpocapsae were found. This was the first confirmed record of S. carpocapsae in the UK.

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Virulence of entomopathogenic nematodes (Rhabditida: Steinernematidae, Heterorhabditidae) to spittlebug Mahanarva spectabilis (Hemiptera: Cercopidae)

Arquivos do Instituto Biológico ◽

10.1590/1808-1657001152012 ◽

2014 ◽

Vol 81 (2) ◽

pp. 145-149 ◽

Cited By ~ 7

Author(s):

Elder Simões de Paula Batista ◽

Alexander Machado Auad ◽

Vanessa Andaló ◽

Caio Márcio de Oliveira Monteiro

Keyword(s):

Pest Management ◽

Entomopathogenic Nematodes ◽

Insect Pests ◽

Steinernema Carpocapsae ◽

Pathogenic Agent ◽

Chemical Agents ◽

Virulent Strains ◽

Chemical Products ◽

Control Insect ◽

New Strategies

The spittlebug can seriously limit the production of forage, and the use of chemical products to control insect pests is costly and can harm the environment. Thus, there is a need to reduce the reliance on chemical agents by developing new strategies. The virulence of nine strains of entomopathogenic nematodes (EPNs) to spittlebugs was investigated under laboratory and greenhouse conditions. Fourth/fifth-instar nymphs of Mahanarva spectabilis were exposed to EPNs in the laboratory and the most virulent strains were applied on the nymphs in the greenhouse at concentrations of 2,000 and 4,000 EPNs/mL. The efficacy of the pathogenic agent was confirmed by the dissection of dead hosts. All the tested strains were pathogenic to the M. spectabilis nymphs in laboratory, particularly Steinernema carpocapsae, S. feltiae, S. riobrave and Heterorhabditis amazonensis RSC1, each of which caused nymph mortality higher than 80%. The concentration did not influence the efficiency of the strains, and those selected in the laboratory had similar efficiency in the greenhouse, except for S. carpocapsae, which was not as effective as the others. Entomopathogenic nematodes can be included in integrated pest management programs to M. spectabilis.

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Virulence comparisons of high-temperature-adapted Heterorhabditis bacteriophora, Steinernema feltiae and S. carpocapsae

Helminthologia ◽

10.1515/helmin-2015-0021 ◽

2015 ◽

Vol 52 (2) ◽

pp. 118-122 ◽

Cited By ~ 1

Author(s):

I. A. Susurluk ◽

T. C. Ulu

Keyword(s):

High Temperature ◽

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Insect Pests ◽

Nematode Species ◽

Heterorhabditis Bacteriophora ◽

Steinernema Feltiae ◽

Safe Alternative ◽

Significant Difference ◽

Environmentally Safe

Summary Entomopathogenic nematodes (EPNs) are environmentally safe alternative control agents. Nematodes in the Heterorhabditidae and Steinernematidae families are widely used in biological control frameworks, especially for soil-inhabiting insect pests. In this experiment, Heterorhabditis bacteriophora (Poinar, 1976), Steinernema feltiae (Filipjev, 1934) and S. carpocapsae (Weiser, 1955) adapted at high temperature were assessed in order to detect differences in virulence between adapted and non-adapted populations. All species were exposed to 38 °C for 2 h. After this treatment, live infective juveniles (IJs) were used to infect to last instar Galleria mellonella (Linnaeus, 1758). larvae at the following doses: 1, 2, 3, 4 and 5 IJs/larva. The LD50 and LD90 were obtained for these species. Non-adapted populations of the nematode species were used as controls for this experiment. The results indicated that differences in S. feltiae and S. carpocapsae virulence between the adapted and non-adapted populations were significant; no significant difference was observed between the adapted and non-adapted H. bacteriophora populations.

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Bio-efﬁcacy of entomopathogenic nematodes, Steinernema feltiae and Heterorhabditis bacteriophora against the Cabbage butterfly Pieris brassicae (L.), under laboratory conditions

10.21203/rs.3.rs-304688/v1 ◽

2021 ◽

Author(s):

Kasi Indra Kumar ◽

Mohinder Singh ◽

Kanchhi Maya Waiba ◽

Sharma Monika ◽

MA Waseem ◽

...

Keyword(s):

Larvicidal Activity ◽

Entomopathogenic Nematodes ◽

Insect Pests ◽

Larval Mortality ◽

Petri Dish ◽

Pieris Brassicae ◽

Steinernema Feltiae ◽

Pupal Development ◽

Cabbage Butterfly ◽

Cabbage Pests

Abstract BACKGROUND: Keeping in view the serious health and environmental apprehensions associated with the use of pesticides, entomopathogenic nematodes have the potential to supersede larvicidal activity for the management of various insect pests. RESULT: The lab experiments were conducted to test the pathogenicity of two EPNs species S. feltiaeand H. bacteriophora at different (IJs/cm2) concentrations against cabbage pests. Based on the pathogenicity of strains, only two isolates effectively show larvicidal activity. The native isolate was obtained from soil samples, collected from Rajgarh, Hamachi Pradesh, India. Petri dish bioassay use nematodes S. feltiae HR1 and H. bacteriophora HR2 species dose (0, 10, 20, 40, 80, 160/ IJs/cm2). The highest (%) 2nd instar larval mortality was recorded in treatments with H. bacteriophora and S. feltiae @ 160 /IJs/cm-2 were (72.08, 67.42 percent). And 4th instar larval mortality was recorded in treatment with H. bacteriophora, and S. feltiae @ 160 /IJs/cm-2 were (85.38,69.50 percent). The next best treatments in order of their efficacy’s pupae mortality were H. bacteriophora and S. feltiae @ 160 /IJs/cm-2 (74.12, percent) both are seam result, H. bacteriophora and S. feltiae @ 80 /IJs/cm-2 (62.12, 58.58 percent). Larvicidal activity after 48- and 72-hours exposure, the S. feltiae and H. bacteriophora (1.0, 1.30, 1.60, 1.90, 2.20 /IJs/cm2) showed potent larvicidal activity with LC50, LC75 and LC90 of all instars and pupae show high mortality. The strain inhibits the larval and pupal development 48 to 72 hr exposer time with LC50 range from 11.30 to 39.94, LC75 18.15 to 73.54, LC90 61.80 to 99.21.CONCLUSION: These studies demonstrate the challenge for cabbage butterfly P. brassicae. The local indigenous strains of EPNs (S. feltiae HR1, H. bacteriophora HR2) as a good biocontrol agent against, cruciferous vegetables crop pest P. brassicae.

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