Relative Importance of Neutral Lipids and Glycogen as Energy Stores in Dauer Larvae of Two Entomopathogenic Nematodes, Steinernema carpocapsae and Steinernema feltiae

Author(s):  
Denis J Wright ◽  
P.S Grewal ◽  
Michael Stolinski
Nematology ◽  
2003 ◽  
Vol 5 (4) ◽  
pp. 539-547 ◽  
Author(s):  
Dammini Premachandra ◽  
Christian Borgemeister ◽  
Oliver Berndt ◽  
Ralf-Udo Ehlers ◽  
Hans-Michael Poehling

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.


2021 ◽  
Vol 37 ◽  
pp. e37047
Author(s):  
Sandra Mara Chaneiko ◽  
Andressa Lima de Brida ◽  
Daniel Bernardi ◽  
Luis Garrigós Leite ◽  
Flávio Roberto Mello Garcia

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.


1997 ◽  
Vol 75 (12) ◽  
pp. 2137-2141 ◽  
Author(s):  
Ganpat B. Jagdale ◽  
Roger Gordon

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.


2004 ◽  
Vol 94 (4) ◽  
pp. 297-306 ◽  
Author(s):  
S. Arthurs ◽  
K.M. Heinz ◽  
J.R. Prasifka

AbstractApplications of entomopathogenic nematodes in the families Steinernematidae and Heterorhabditidae have traditionally been targeted against soil insects. Nonetheless, research over the last two decades highlights the potential of such agents against above-ground pests under certain circumstances. A general linear model was used to test for patterns in efficacy among 136 published trials with Steinernema carpocapsae Weiser, the most common species applied against foliar and other above-ground pests. The focus was on field and greenhouse assessments, rather than laboratory assays where relevant ecological barriers to infection are typically removed. The model showed differences in nematode treatment efficacy depending on the pests’ target habitat (bore holes > cryptic foliage > exposed foliage) and trial location (greenhouse > field studies). Relative humidity and temperature during and up to 8 h post-application were also predicted to influence rates of nematode infection obtained. Conversely, spray adjuvants (both wetting agents and anti-desiccants) and nematode dosage applied (both concentration and use of consecutive applications 3–4 days apart) did not explain a significant amount of variance in nematode performance. With reference to case studies the model is used to discuss the relative importance of different factors on nematode efficacy and highlight priorities for workers considering using entomopathogenic nematodes to target pests in novel environments.


Nematology ◽  
2009 ◽  
Vol 11 (1) ◽  
pp. 107-116 ◽  
Author(s):  
Naser Eivazian Kary ◽  
Gholamreza Niknam ◽  
Seyed Abolgasem Mohammadi ◽  
Christine Griffin ◽  
Mohammad Moghaddam

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.


Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 117 ◽  
Author(s):  
Maurizio Brivio ◽  
Maristella Mastore

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.


Parasitology ◽  
1997 ◽  
Vol 114 (5) ◽  
pp. 489-496 ◽  
Author(s):  
M. N. PATEL ◽  
M. STOLINSKI ◽  
D. J. WRIGHT

An 8-point visual index was developed for Oil Red O staining of neutral lipids in infective juveniles (IJs) of Steinernema carpocapsae (All), S. riobravis (Biosys 355), S. feltiae (UK76) and S. glaseri (NC). The visual index was found to be a reliable and rapid method for determining the relative neutral lipid content of individual IJs and was validated quantitatively by gas chromatography. The relationship between neutral lipid utilization and infectivity of IJs stored in distilled water at 25°C was also investigated and the first quantitative results on neutral lipid utilization in entomopathogenic nematodes are reported. Neutral lipid contents of freshly harvested IJs of S. carpocapsae, S. riobravis, S. feltiae and S. glaseri were 31, 31, 24 and 26% dry wt, respectively. Steinernema carpocapsae showed a sigmoidal pattern for neutral lipid utilization while S. riobravis used neutral lipids at an almost constant rate. Survivorship of these two species ranged between 120 and 135 days, whereas S. feltiae and S. glaseri lived >450 days and had a slower rate of lipid utilization during a 260 day storage period. Oil Red O staining showed that individual IJs in each population utilized lipids at different rates, even though they had the same initial lipid index. The infectivity of S. riobravis, S. feltiae and S. glaseri declined with lipid utilization. In contrast, S. carpocapsae maintained a high level of infectivity even at relatively low lipid levels. Therefore, neutral lipid content was found to be a suitable indicator of infectivity for S. riobravis, S. feltiae and S. glaseri but not for S. carpocapsae.


2018 ◽  
Vol 20 (2) ◽  
pp. 91-101
Author(s):  
Andressa Lima de Brida ◽  
Silvia Renata Siciliano Wilcken ◽  
Luis Garrigós Leite

Nematoides entomopatogênicos (NEPs) são alternativas eficientes para o controle de pragas. O emprego de novas técnicas da produção in vivo, permite o progresso da tecnologia de formulação de bioinseticidas. O objetivo do trabalho, foi avaliar a influência da luminosidade e do substrato na capacidade de infecção de juvenis infectantes (JIs) de Steinernema brazilense IBCBn 06, Steinernema carpocapsae IBCBn 02, Steinernema feltiae IBCBn 47 e Heterorhabditis amazonensis IBCBn 24 em lagartas de Galleria mellonella (Lepidoptera: Pyralidae). O delineamento experimental foi inteiramente casualizado com quatro tratamentos e oito repetições. As parcelas, constituídas por placa de Petri com, substrato-areia e substrato-papel filtro, com e sem luminosidade, inoculados com suspensão de 1,5 mL contendo 400JIs e quatro lagartas de G. mellonella. O número de JIs foi quantificado após a mortalidade das lagartas. A taxa de infecção de JIs de S. carpocapsae IBCBn 02 e S. feltiae IBCBn 47 variaram de 2,14 a 3,28 e de 11,04 a 13,09 JIs/lagarta. O substrato-areia com e sem luminosidade permitiu a maior taxa de infeção dos JIs de S. brazilense IBCBn 06 de 7,86 e 9,44 JIs/lagarta, e 13,49 JIs/lagarta com luminosidade para H. amazonensis IBCBn 24. O substrato-areia, permite a maior taxa de infecção por JIs de NEPs.


Author(s):  
Maguintontz Cedney Jean-Baptiste ◽  
Andressa Lima de Brida ◽  
Daniel Bernardi ◽  
Sérgio da Costa Dias ◽  
Juliano de Bastos Pazini ◽  
...  

Abstract The Mediterranean fruit fly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is among the main pests of fruit crops worldwide. Biological control using entomopathogenic nematodes (EPNs) may be an alternative to suppress populations of this pest. Thus, the aim of this study was to evaluate the pathogenicity and virulence of six EPN isolates (Heterorhabditis bacteriophora HB, H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47, and S. brazilense IBCB-n06) against C. capitata pupae. The compatibility of EPNs with different chemical insecticides that are registered for management of C. capitata was also assessed. Isolates of H. bacteriophora HB and S. brazilense IBCB-n06 at a concentration of 1,000 infective juveniles (IJ)/ml proved to be most pathogenic to C. capitata (70 and 80% mortality, respectively). In contrast, the isolates H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47 provided pupal mortality of less than 60%. Bioassays to determine lethal concentrations indicated that concentrations of 600 IJ/ml (H. bacteriophora HB) and 1,000 IJ/ml (S. brazilense IBCB-n06) showed the highest virulence against C. capitata pupae. In contrast, the highest numbers of IJs emerged at concentrations of 1,200 and 200 IJ/ml. In compatibility bioassays, malathion, spinetoram, phosmet, acetamiprid, and novaluron were considered compatible with and harmless (Class 1) to H. bacteriophora HB and S. brazilense IBCB-n06, according to IOBC/WPRS. This information is important for implementing integrated management programs for C. capitata, using biological control with EPNs, whether alone or in combination with chemical insecticides.


Nematology ◽  
1999 ◽  
Vol 1 (7) ◽  
pp. 735-743 ◽  
Author(s):  
Parwinder S. Grewal ◽  
Edwin E. Lewis ◽  
Sudha Venkatachari

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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