Identification of entomopathogenic nematodes and their symbiotic bacteria in national parks of Thailand, and mosquitocidal activity of Xenorhabdus griffiniae against Aedes aegypti larvae

Summary Entomopathogenic nematodes (EPN) Steinernema and Heterorhabditis with symbionts with Xenorhabdus and Photorhabdus bacteria, respectively, are reported as biocontrol agents for insect control. The objectives of this study were to identify EPN and their symbiotic bacteria in national parks of Phitsanulok Province, Thailand, and to test how Xenorhabdus isolates attack Aedes aegypti larvae. We collected 810 soil samples from four national parks. The juvenile stage of EPN was isolated from soil samples using a baiting technique with Galleria mellonella followed by a White trap. Partial regions of 28S rDNA and internal transcript spacer were sequenced to identify EPN, and recA sequencing was used to discriminate between Xenorhabdus and Photorhabdus. We found that 74 of the 810 soil samples (9.1%) were positive for the EPN. The EPN were molecularly identified as S. surkhetense, S. longicaudum, H. indica and Heterorhabditis sp. SGmg3, and their symbiotic bacteria were identified as X. stockiae, X. griffiniae, X. indica, X. vietnamensis, P. luminescens subsp. akhurstii, and P. temperata subsp. temperata. Xenorhabdus griffiniae showed potential larvicidal activity against A. aegypti (91% mortality at 72 and 96 h after exposure). This study demonstrates the diversity of EPN and symbiotic bacteria in national parks of Thailand and the potential to use X. griffiniae as a biocontrol agent to kill A. aegypti larvae.

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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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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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Identification of entomopathogenic nematodes and symbiotic bacteria from Nam Nao National Park in Thailand and larvicidal activity of symbiotic bacteria against Aedes aegypti and Aedes albopictus

PLoS ONE ◽

10.1371/journal.pone.0195681 ◽

2018 ◽

Vol 13 (4) ◽

pp. e0195681 ◽

Cited By ~ 12

Author(s):

Temsiri Yooyangket ◽

Paramaporn Muangpat ◽

Raxsina Polseela ◽

Sarunporn Tandhavanant ◽

Aunchalee Thanwisai ◽

...

Keyword(s):

Aedes Aegypti ◽

Larvicidal Activity ◽

Aedes Albopictus ◽

National Park ◽

Entomopathogenic Nematodes ◽

Symbiotic Bacteria

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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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Analysis of two isolates of a Heterorhabditis bacteriophora population detected in Córdoba, Argentina

Nematology ◽

10.1163/156854100509231 ◽

2000 ◽

Vol 2 (4) ◽

pp. 473-476

Author(s):

María Bertolotti ◽

Gladys De Sousa ◽

Mónica Valenzuela ◽

María M.A. De Doucet

Keyword(s):

Soil Sample ◽

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Heterorhabditis Bacteriophora ◽

Symbiotic Bacteria ◽

Taxonomic Character ◽

Morphometric Characters ◽

Isozyme Patterns ◽

Taxonomic Studies

AbstractEntomopathogenic nematodes of the genus Heterorhabditis are associated with symbiotic bacteria Photorhabdus spp. (Enterobacteriaceae). Taxonomic studies confirm that each species of nematode has a specific natural association with only one species of bacterium (Boemare & Doucet, 1996). Except in a few cases, the bacteria change the colour of the parasitized insect to different reddish tones and produce bioluminescence (Grimont et al., 1984; Boemare & Doucet, 1996). These distinct colours would be assumed to be due to the different species of Photorhabdus and, consequently, to indicate different species of Heterorhabditis. Therefore, the colour of the cadaver has been used as a taxonomic character (Stock, 1993). In a single soil sample from Córdoba City, Argentina, two isolates of Heterorhabditis were found that were clearly distinguished by the colour of the parasitized Galleria mellonella larva: isolate A, violet-brown; B, reddish. These different phenotypes led us to suppose that the nematode isolates were associated with different symbiotic bacteria and that the nematodes were different species. The purposes of this work were: to establish the identity of the isolates and to compare them on the basis of morphological and morphometric characters, and isozyme patterns.

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Physico-chemical properties and mode of action of a signal from the symbiotic bacterium Photorhabdus luminescens inducing dauer juvenile recovery in the entomopathogenic nematode Heterorhabditis bacteriophora

Nematology ◽

10.1163/156854101753625344 ◽

2001 ◽

Vol 3 (8) ◽

pp. 849-853 ◽

Cited By ~ 12

Author(s):

Ralf-Udo Ehlers ◽

Jens Aumann

Keyword(s):

Entomopathogenic Nematodes ◽

Entomopathogenic Nematode ◽

Chemical Properties ◽

Symbiotic Bacterium ◽

Heterorhabditis Bacteriophora ◽

Juvenile Stage ◽

Food Sources ◽

Symbiotic Bacteria ◽

Photorhabdus Luminescens ◽

Physico Chemical

AbstractRecovery in entomopathogenic nematodes is the exit from the dauer juvenile stage. It is a response to environmental queues signalling the presence of food sources (e.g., insect haemolymph). The bacterium Photorhabdus luminescens excretes a signal which also induces recovery of its symbiotic Heterorhabditis bacteriophora dauer juveniles. This bacterial signal is composed of at least two compounds with different polarity. The symbiotic bacteria also secrete an antagonistic signal which inhibits nematode recovery. The recovery-inducing signal compounds have a molecular mass of less than 20 kDa and are negatively charged. The data indicate that at least one compound is smaller than 5 kDa. The bacterial signal triggers by receptor binding, the first step in a recovery-inducing muscarinic signalling pathway.

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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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Surface protein components from entomopathogenic nematodes and their symbiotic bacteria: effects on immune responses of the greater wax moth,Galleria mellonella(Lepidoptera: Pyralidae)

Pest Management Science ◽

10.1002/ps.4905 ◽

2018 ◽

Vol 74 (9) ◽

pp. 2089-2099 ◽

Cited By ~ 12

Author(s):

Maurizio Francesco Brivio ◽

Andrea Toscano ◽

Simone Maria De Pasquale ◽

Andrea De Lerma Barbaro ◽

Stefano Giovannardi ◽

...

Keyword(s):

Immune Responses ◽

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Surface Protein ◽

Symbiotic Bacteria ◽

Greater Wax Moth ◽

Lepidoptera Pyralidae ◽

Protein Components ◽

Wax Moth

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Distribution and diversity of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in a South African nature reserve

Koedoe ◽

10.4102/koedoe.v63i1.1661 ◽

2021 ◽

Vol 63 (1) ◽

Author(s):

Isiah Nthenga ◽

Rinus Knoetze ◽

Antoinette P. Malan

Keyword(s):

Entomopathogenic Nematodes ◽

Nature Reserve ◽

Galleria Mellonella ◽

Codling Moth ◽

Cape Floristic Region ◽

Soil Samples ◽

Biocontrol Agents ◽

Its2 Region ◽

Western Cape ◽

Two Samples

Entomopathogenic nematodes (EPNs) are microscopic roundworms that are found in soil worldwide. They deliver an important ecosystem service through preventing natural flares in insect reproduction by means of utilising the soil stages of insects as a food source and by acting as natural biocontrol agents. A survey of EPNs was conducted in the JS Marais Nature Reserve, Stellenbosch, in the Western Cape province of South Africa. Soil samples were baited with the larvae of three susceptible hosts, codling moth (Cydia pomonella), wax moth (Galleria mellonella) and mealworm (Tenebrio molitor) to determine the presence of EPN. Of the 76 soil samples collected across the reserve, 39 were found to be positive for the presence of EPN (51.32%). Among the positive samples, 87% contained Steinernema isolates, 8% contained Heterorhabditis and 5% contained the Oscheius sp. Morphological and molecular studies were performed to characterise the isolates to species level. The Steinernema species were identified as Steinernema khoisanae in 34 samples, and as Steinernema nguyeni in five samples. The only species of Heterorhabditis found was H. safricana, which was identified from three samples. An unknown Oscheius sp. was found in two samples. The reserve’s population of S. khoisanae showed interesting inter-individual variation (93%) early in the internal transcribe spacer (ITS) region, leading to short single-usable sequences, which, in most cases, included only the ITS1 or ITS2 region. However, using the D2D3 confirmed their identity as S. khoisanae, with such occurring in all areas and soil types of the reserve.Conservation implications: The undisturbed alluvial fynbos and renosterveld of the JS Marais Nature Reserve showed high EPN abundance and diversity in stark contrast to the agro-ecosystems present in the Cape floristic region. This finding, on a micro level, should be conserved for future bioprospecting in the fynbos for EPNs with potential as biocontrol agents.

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DESCRIPTION OF NEW SPECIES OF METARHABDITIS LONGICAUDATUS (NEMATODA: RHABDITIDAE) WITH THREE NEW RECORDS FROM SINDH, PAKISTAN

Plant Protection ◽

10.33804/pp.003.03.3110 ◽

2019 ◽

Vol 3 (3) ◽

pp. 131-139

Author(s):

Tabassum Ara Khanum, Salma Javed, Nasir Mehmood

Keyword(s):

New Species ◽

Entomopathogenic Nematodes ◽

New Records ◽

Galleria Mellonella ◽

Insect Pests ◽

Nematode Species ◽

Soil Samples ◽

Large Size ◽

Tail Spike ◽

First Time

Many rhabditid nematodes like Metarhabditis belonging to the bacteriophage group are considered to be necromenic associates of insects and used to be facultative entomopathogenic nematodes or as biocontrol agents. These nematodes can be safely used against insect pests of different crops and vegetables. In the present study, nematode specimens of new and known species were collected from different areas of Sindh and isolated from soil samples by baiting technique using last instar Galleria mellonella. One new nematode species Metarhabditis longicaudata n. sp. and three new records of M. adenobia, M. amasactae, and M. rainai (Nematoda: Rhabditidae) were found from Sindh. M. longicaudata n. sp. differed from the species of the genus Metarhabditis by having long un-covered tail spike. It was also characterized by a large sized male 1286 (1154-1325) µm; longer male tail 69.5 (62-76) µm; longer spicule 43 (40-46) µm; leptoderan bursa; longer gubernaculum 27 (20-34) µm. The female was also of large size of 1507 (1366-1684) µm with larger tail 102 (94-112) µm and longer pharynx 231 (206-265) µm. The genus Metarhabditis is reported for the first time from Sindh, Pakistan.

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