Efficacy of Egyptian ( ba1 ) and German ( hb1-3 ) Strains of Entomopathogenic Nematode , Heterorhabditis Bacteriophora against Galleria Mellonella L.

2013 ◽  
Vol 60 ◽  
pp. 143-154
Author(s):  
G. M. Nouh ◽  
M. A. Hussein
1990 ◽  
Vol 122 (2) ◽  
pp. 309-319 ◽  
Author(s):  
O.N. Morris ◽  
V. Converse ◽  
J. Harding

AbstractNine entomopathogenic nematode–bacteria complexes were screened for their virulence against larvae of six noctuids, a geometrid, and a pyralid. Ninety-six-hour LD50’s of steinernematids (and heterorhabditids) ranged from 1 to 3 (1–8) infective juveniles in Galleria mellonella (L.), 1–71 (2) in Peridroma soucia (Hbn.), 1–10 (1–3) in Mamestra configurata (Wlk.), 1–28 (3–7) in Euxoa ochrogaster (Gn.), 19 in Lacanobia radix (Wlk.), 22–60 (4) in Pseudaletia unipuncta (Haw.), 2–95 (111) in Agrotis ipsilon (Hufn.), and 3–28 in Paleacrita vernata (Peck). The nematode, Steinernema feltiae LIC, a cold-hardy strain isolated in Newfoundland, was highly virulent for G. mellonella and M. configurata, but not for P. soucia and E. ochrogaster. The number of nematodes invading larvae and the number produced were greater in G. mellonella than in other insects tested. Nematode–bacteria complexes that showed potential for controlling cutworms included S. feltiae, S. glaseri, S. bibionis, Heterorhabditis bacteriophora, and H. heliothidis.


Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 353 ◽  
Author(s):  
Sara Eliáš ◽  
Jana Hurychová ◽  
Duarte Toubarro ◽  
Jorge Frias ◽  
Martin Kunc ◽  
...  

Entomopathogenic nematodes (EPNs) are efficient insect parasites, that are known for their mutualistic relationship with entomopathogenic bacteria and their use in biocontrol. EPNs produce bioactive molecules referred to as excreted/secreted products (ESPs), which have come to the forefront in recent years because of their role in the process of host invasion and the modulation of its immune response. In the present study, we confirmed the production of ESPs in the EPN Heterorhabditis bacteriophora, and investigated their role in the modulation of the phenoloxidase cascade, one of the key components of the insect immune system. ESPs were isolated from 14- and 21-day-old infective juveniles of H. bacteriophora, which were found to be more virulent than newly emerged nematodes, as was confirmed by mortality assays using Galleria mellonella larvae. The isolated ESPs were further purified and screened for the phenoloxidase-inhibiting activity. In these products, a 38 kDa fraction of peptides was identified as the main candidate source of phenoloxidase-inhibiting compounds. This fraction was further analyzed by mass spectrometry and the de novo sequencing approach. Six peptide sequences were identified in this active ESP fraction, including proteins involved in ubiquitination and the regulation of a Toll pathway, for which a role in the regulation of insect immune response has been proposed in previous studies.


Nematology ◽  
2006 ◽  
Vol 8 (3) ◽  
pp. 397-409 ◽  
Author(s):  
Anwar L. Bilgrami ◽  
Randy Gaugler ◽  
David I. Shapiro-Ilan ◽  
Byron J. Adams

Abstract The stability of traits important for biological control was studied in the entomopathogenic nematode-bacteria complexes Heterorhabditis bacteriophora and Steinernema carpocapsae. Five experimental lines of each species were subcultured for 20 serial passages in Galleria mellonella larvae to assess trait stability. Subculturing impaired performance of both H. bacteriophora and S. carpocapsae. Virulence, heat tolerance and fecundity deteriorated in all H. bacteriophora experimental lines, and four out of five experimental lines deteriorated in host-finding ability. All S. carpocapsae experimental lines deteriorated in heat tolerance and nictation, and four out of five experimental lines declined for reproductive capacity, whereas virulence declined in two experimental lines. Determination of whether trait deterioration was due to changes in nematode, bacteria, or both symbiotic partners was tested by exchanging nematodes or bacteria from control populations with nematodes or bacteria from the most deteriorated experimental lines and assessing trait recovery. The source of deterioration varied according to trait, but only the bacterial partner played a role in trait reductions for every trait and species, whereas the nematode was the main source only for S. carpocapsae nictation. These results emphasise the important role each symbiotic partner plays in the stability and expression of beneficial traits.


2015 ◽  
Vol 128 ◽  
pp. 31-36 ◽  
Author(s):  
Itamar Glazer ◽  
Liora Salame ◽  
Levana Dvash ◽  
Hussein Muklada ◽  
Hassan Azaizeh ◽  
...  

Nematology ◽  
2002 ◽  
Vol 4 (8) ◽  
pp. 925-932 ◽  
Author(s):  
Rodney Edmondson ◽  
Paul Richardson ◽  
Deena Willmott ◽  
Andrew Hart ◽  
Steve Long

AbstractThe susceptibility of overwintering black vine weevil larvae Otiorhynchus sulcatus to a cold-active entomopathogenic nematode, Steinernema kraussei (isolate L137) and a commercial proprietary biopesticide, Steinernema carpocapsae (Exhibit) was assessed on outdoor potted strawberry plants. Nematodes were applied at a range of doses in early winter at a field site located in Warwickshire, England. Three months later, infestation and mortality of vine weevils were assessed. There was a clear dose response observed for S. kraussei applications. Up to 81% of vine weevil control was recorded by this nematode at the highest dose of 60 000 nematodes per pot, whereas treatments with S. carpocapsae caused no significant mortality at the dose rates used. Dissection of vine weevil larvae showed infective juveniles had developed to adults within the host. Recovery of nematodes at the end of the experiment indicated that S. kraussei (L137) was able to survive winter field conditions including prolonged exposure to low temperatures (averaging 2.7°C during the experiment) in contrast to S. carpocapsae which showed poor survival. Of the two extraction methods used, the Baermann funnel technique was found to be more efficient than Galleria mellonella baiting, with up to 44% of the original highest dose of S. kraussei nematodes being recovered by Baermann funnel compared to 8% with G. mellonella at 18°C. These results suggest S. kraussei (L137) has potential as a commercial biocontrol agent against O. sulcatus at low temperatures.


BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Neil D. Warnock ◽  
Deborah Cox ◽  
Ciaran McCoy ◽  
Robert Morris ◽  
Johnathan J. Dalzell

Abstract Background Steinernema carpocapsae is an entomopathogenic nematode that employs nictation and jumping behaviours to find potential insect hosts. Here we aimed to investigate the transcriptional basis of variant host-finding behaviours in the infective juvenile (IJ) stage of three S. carpocapsae strains (ALL, Breton and UK1), with a focus on neuronal genes known to influence behaviour in other nematode species. Identifying gene expression changes that correlate with variant host-finding behaviours will further our understanding of nematode biology. Results RNA-seq analysis revealed that whilst up to 28% of the S. carpocapsae transcriptome was differentially expressed (P < 0.0001) between strains, remarkably few of the most highly differentially expressed genes (> 2 log2 fold change, P < 0.0001) were from neuronal gene families. S. carpocapsae Breton displays increased chemotaxis toward the laboratory host Galleria mellonella, relative to the other strains. This correlates with the up-regulation of four srsx chemosensory GPCR genes, and a sodium transporter gene, asic-2, relative to both ALL and UK1 strains. The UK1 strain exhibits a decreased nictation phenotype relative to ALL and Breton strains, which correlates with co-ordinate up-regulation of neuropeptide like protein 36 (nlp-36), and down-regulation of an srt family GPCR gene, and a distinct asic-2-like sodium channel paralogue. To further investigate the link between transcriptional regulation and behavioural variation, we sequenced microRNAs across IJs of each strain. We have identified 283 high confidence microRNA genes, yielding 321 predicted mature microRNAs in S. carpocapsae, and find that up to 36% of microRNAs are differentially expressed (P < 0.0001) between strains. Many of the most highly differentially expressed microRNAs (> 2 log2 fold, P < 0.0001) are predicted to regulate a variety of neuronal genes that may contribute to variant host-finding behaviours. We have also found evidence for differential gene isoform usage between strains, which alters predicted microRNA interactions, and could contribute to the diversification of behaviour. Conclusions These data provide insight to the transcriptional basis of behavioural variation in S. carpocapsae, supporting efforts to understand the molecular basis of complex behaviours in nematodes.


Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 144 ◽  
Author(s):  
Esengül Özdemir ◽  
Şerife Bayram ◽  
İ. Alper Susurluk

The entomopathogenic nematode Steinernema litorale was isolated from Çamkoru Nature Park located in Ankara, Turkey, in September 2018. Steinernema litorale was recovered in 1 of 67 soil samples from a natural forest area; the soil was characterised as sandy loam. The isolated nematode S. litorale was identified based on morphological and molecular parameters. The symbiotic bacterium of S. litorale was determined as Xenorhabdus bovienii. Steinernema litorale was found for the first time in Turkey and the Middle East. The virulence of the isolate was tested on Galleria mellonella larvae. Different concentrations of the nematode (10, 25, 50, 75, and 100 infective juveniles (IJs/larvae) were used. While the LC50 values at 48 h, 72 h, and 96 h were 153.419, 51.005, and 15.439 IJs, respectively, and the LT50 values at 75 IJs and 100 IJs showed that this isolate is capable to control insect larvae within 50.083 and 36.266 h, respectively.


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