Host-finding ability of three entomopathogenic nematode isolates in the presence of plant roots

Nematology ◽  
2003 ◽  
Vol 5 (4) ◽  
pp. 601-608 ◽  
Author(s):  
G. Christopher Cutler ◽  
John Webster
Keyword(s):  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Petri Dish ◽  
Host Finding ◽  
Plant Roots ◽  
Tomato Root ◽  
Tomato Seedling ◽  
Bean Plants ◽  
Tomato Roots

Abstract The effect of plant roots on the host-finding ability of three isolates of entomopathogenic nematodes (EPN), Heterorhabditis bacteriophora D-H-Da1, Steinernema sp. Dongrae and Steinernema sp. BJ was studied. In Petri dish experiments the overall response of the infective juveniles (IJ) of these isolates differed from one another, but all were attracted to a Galleria mellonella larva and to a tomato seedling when either of these targets was presented with a blank control. The BJ and D-H-Da1 IJ aggregated more around a tomato root than a G. mellonella larva when these targets were presented separately, but showed no preference for a G. mellonella-tomato seedling combination over a blank control. Dongrae IJ showed no preference for a G. mellonella larva or tomato seedling when each was presented simultaneously in the same Petri dish. In experiments in pots of soil, plant roots did not affect the host-finding ability of Dongrae IJ. In contrast, compared to control pots with no roots, roots of bean plants hindered the ability of BJ IJ to infect a G. mellonella larva, but tomato roots increased host-finding by D-H-Da1 IJ. Roots of certain plant species modify the host-finding ability of EPN, but the extent and direction of the response varied with the EPN applied.

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

Nematology ◽  
1999 ◽  
Vol 1 (7) ◽  
pp. 735-743 ◽  
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.

scholarly journals Transcriptional variation and divergence of host-finding behaviour in Steinernema carpocapsae infective juveniles

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Neil D. Warnock ◽  
Deborah Cox ◽  
Ciaran McCoy ◽  
Robert Morris ◽  
Johnathan J. Dalzell
Keyword(s):  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Gene Families ◽  
Nematode Species ◽  
Host Finding ◽  
Steinernema Carpocapsae ◽  
Differentially Expressed ◽  
Infective Juvenile ◽  
Neuronal Genes ◽  
Sodium Transporter

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.

Sex and the dynamics of infection in the entomopathogenic nematode Steinernema feltiae

1997 ◽  
Vol 71 (3) ◽  
pp. 197-202 ◽  
Author(s):  
D.A. Bohan ◽  
W.M. Hominick
Keyword(s):  
Sex Ratio ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Steinernema Feltiae ◽  
Infective Juvenile ◽  
Infective Stage ◽  
Male And Female ◽  
Per Capita ◽  
Infection Interaction

AbstractAn infection experiment was conducted to assess the change in the proportions of Steinernema feltiae Filipjev (Site 76 strain) infective juveniles becoming male or female on exposure to the test host Galleria mellonella L. Using a mathematical model for the infection interaction, the per capita probability of penetration per unit time (transmission coefficient), for those juveniles becoming male or female, and the magnitude of the male and female classes in the infective juvenile pool were estimated. The results show that S. feltiae infective juveniles which subsequently become female have a greater probability of invasion into test hosts than their male counterparts, which leads to markedly female biased sex ratios during the initial stages of the infection interaction. As the infection progresses, however, it was found that the sex ratio became balanced. This was because the underlying sex ratio in the infective stage pool was balanced. The implications of this dynamism in the sex ratio of the entomopathogenic nematodes are discussed with respect to the infection interaction, transmission and the likely environment in which the infective juveniles reside.

Natural occurrence of entomopathogenic nematodes (Rhabditida: Steinernematidae) on golf courses in eastern Canada

Nematology ◽  
2007 ◽  
Vol 9 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Julie Dionne ◽  
Guy Bélair ◽  
S. Patricia Stock ◽  
Louis Simard ◽  
Hervé Mauléon
Keyword(s):  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Sequence Data ◽  
Entomopathogenic Nematode ◽  
Natural Occurrence ◽  
Golf Courses ◽  
Eastern Canada ◽  
Rdna Sequence Data ◽  
Listronotus Oregonensis ◽  
28S Rdna Sequence

AbstractA survey of entomopathogenic nematodes from 38 golf courses was conducted in different climatic areas of Ontario and Québec provinces, Canada, during autumn 2002 and 2003. Soil samples were collected on golf course greens, fairways and roughs. Entomopathogenic nematodes were isolated from soil using wax moth (Galleria mellonella) and carrot weevil (Listronotus oregonensis) larvae as bait. Of the 436 samples (218 sites), 11 contained entomopathogenic nematodes for this study. All entomopathogenic nematode-positive samples were isolated from roughs. Isolates were characterised using DNA satellite probes and 28S rDNA sequence data. Both methods confirmed the identities of nematode isolates as Steinernema carpocapsae, S. feltiae and S. kraussei.

Mechanism, kinematic performance, and fitness consequences of jumping behavior in entomopathogenic nematodes (Steinernema spp.)

1999 ◽  
Vol 77 (12) ◽  
pp. 1947-1955 ◽  
Author(s):  
James F Campbell ◽  
Harry K Kaya
Keyword(s):  
Surface Tension ◽  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Water Film ◽  
Surface Tension Force ◽  
Host Finding ◽  
The Body ◽  
Loop Formation ◽  
Head Region ◽  
Body Regions

The mechanism enabling entomopathogenic nematodes (Steinernema spp.) to jump is described. Jumping performance is measured and the contribution of jumping to host finding is estimated. We used the entomopathogenic nematode Steinernema carpocapsae as a model species for the genus. Nematodes jump using a two-step process of forming and contracting a loop. During loop formation, the nematode bends the anterior half of its body until the head region makes contact with the side of the body. The two body regions are held fast by the surface tension of the water film covering the nematode. When the loop is contracted, the body becomes contorted so that the cuticle kinks. This extreme bending generates and stores sufficient energy that when the surface-tension force is broken the nematode is propelled through the air. The nematode (0.558 mm in length) can jump a distance of 4.8 ± 0.8 mm (mean ± SEM) and a height of 3.9 ± 0.1 mm. The contribution of jumping to host finding varies among species and is related to the foraging strategy used by each species.

scholarly journals An Assessment of Steinernema rarum as a Biocontrol Agent in Sugarcane with Focus on Sphenophorus levis, Host-Finding Ability, Compatibility with Vinasse and Field Efficacy

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 500
Author(s):  
Mateus Salviano Oliveira Silva ◽  
Jorge Franco Maringoli Cardoso ◽  
Maria Elizia Pacheco Ferreira ◽  
Fernando Berton Baldo ◽  
Raphael Satochi Abe Silva ◽  
...  
Keyword(s):  
Galleria Mellonella ◽  
Control Method ◽  
Liquid Fraction ◽  
Entomopathogenic Nematode ◽  
Saccharum Officinarum ◽  
Host Finding ◽  
Alcohol Production ◽  
Field Efficacy ◽  
Sphenophorus Levis ◽  
Sugarcane Pests

In Brazil, countless insect species attack and damage sugarcane (Saccharum officinarum L.), which is an extremely important crop since it is planted on more than 10 million hectares. Among these insects, the sugarcane billbug, Sphenophorus levis (Coleoptera: Curculionidae), is of great importance as the larvae open tunnels in the rhizome of the plant, causing high damage and losses. This insect is attracted mainly to vinasse, which is the liquid fraction generated from the alcohol production and discarded onto the sugarcane fields for fertigation. Toward a novel control method for S. levis, the native entomopathogenic nematode Steinernema rarum (Pam 25) was compared with S. carpocapsae (IL 1) and Heterorhabditis bacteriophora (HBEN01) in respect to their ability to search for larvae of two insect hosts (Galleria mellonella and S. levis) within the cane rhizome. The selected nematode S. rarum was also assessed for rate effects, its survival in vinasse and field efficacy to control sugarcane pests S. levis, Hyponeuma taltula (Lepidoptera, Erebidae) and Leucothyreus alvarengai (Coleoptera: Melolonthidae). Steinernema rarum exhibited superior virulence to G. mellonella and S. levis larvae inserted into the cane rhizomes (75–78% mortality) compared to S. carpocapsae (30–53%) and H. bacteriophora (18–28%). Vinasse affected S. rarum when infective juveniles were suspended in the liquid compost for more than 6 h but did not affect the nematode when kept on the straw and soil treated with the compost. Steinernema rarum tested at 1–3 × 108 infective juveniles/ha on the sugarcane field caused 74.1, 56.3 and 50.6% control of S. levis, L. alvarengai and H. taltula, respectively.

scholarly journals A neuropeptide modulates sensory perception in the entomopathogenic nematode Steinernema carpocapsae

2016 ◽  
Author(s):  
Robert Morris ◽  
Leonie Wilson ◽  
Matthew Sturrock ◽  
Neil D. Warnock ◽  
Daniel Carrizo ◽  
...  
Keyword(s):  
Rna Interference ◽  
Molecular Basis ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Sensory Perception ◽  
Tenebrio Molitor ◽  
Host Finding ◽  
Life Cycles ◽  
Steinernema Carpocapsae ◽  
Rnai Pathway

AbstractEntomopathogenic nematodes (EPNs) employ a sophisticated chemosensory apparatus to detect potential hosts. Understanding the molecular basis of relevant host-finding behaviours could facilitate improved EPN biocontrol approaches, and could lend insight to similar behaviours in economically important mammalian parasites. FMRFamide-like peptides are enriched and conserved across the Phylum Nematoda, and have been linked with motor and sensory function, including dispersal and aggregating behaviours in the free living nematode Caenorhabditis elegans. The RNA interference (RNAi) pathway of Steinernema carpocapsae was characterised in silico, and employed to knockdown the expression of the FMRFamide-like protein 21 (GLGPRPLRFamide) gene (flp-21) in S. carpocapsae infective juveniles; a first instance of RNAi in this genus, and a first in an infective juvenile of any EPN species. Our data show that 5 mg/ml dsRNA and 50 mM serotonin triggers statistically significant flp-21 knockdown (-84%***) over a 48 h timecourse, which inhibits host-finding (chemosensory), dispersal, hyperactive nictation and jumping behaviours. However, whilst 1 mg/ml dsRNA and 50 mM serotonin also triggers statistically significant flp-21 knockdown (-51%**) over a 48 h timecourse, it does not trigger the null sensory phenotypes; statistically significant target knockdown can still lead to false negative results, necessitating appropriate experimental design. SPME GC-MS volatile profiles of two EPN hosts, Galleria mellonella and Tenebrio molitor reveal an array of shared and unique compounds; these differences had no impact on null flp-21 RNAi phenotypes for the behaviours assayed. Localisation of flp-21 / FLP-21 to paired anterior neurons by whole mount in situ hybridisation and immunocytochemistry corroborates the RNAi data, further suggesting a role in sensory modulation. These data can underpin efforts to study these behaviours in other economically important parasites, and could facilitate molecular approaches to EPN strain improvement for biocontrol.Author summaryEntomopathogenic nematodes (EPNs) use a range of behaviours in order to find a suitable host, some of which are shared with important mammalian parasites. The ethical burden of conducting research on parasites which require a mammalian host has driven a move towards appropriate ‘model’ parasites, like EPNs, which have short life cycles, can be cultured in insects or agar plates, and have excellent genomic resources. This study aimed to develop a method for triggering gene knockdown by RNA interference, a biochemical pathway involved in gene regulation. Through knocking down the expression of a target gene we can then study the function of that gene, helping us to understand the molecular basis of behaviour. Here we have characterised the RNAi pathway of Steinernema carpocapsae through analysing the genome sequence for relevant genes, and have successfully knocked down the neuropeptide gene flp-21 in S. carpocapsae infective juveniles. We find that it is involved in the regulation of behaviours which rely on sensory perception and relate to host-finding. We have localised the gene and mature neuropeptide, and find them to be expressed in paired anterior neurons, which is in broad agreement with our behavioural observations following RNAi. Our observations are relevant to interactions of S. carpocapsae with two insect hosts, the waxworm Galleria mellonella, and the meelworm, Tenebrio molitor. We identified the volatile compounds relating to both insects, and find that there are both shared and unique compounds to both species; EPNs use volatile compound gradients, as well as other physical cues in order to find and invade a host. This study provides a method for employing RNAi in a promising model parasite, and characterises the molecular basis of host-finding behaviours which could be relevant to economically important mammalian parasites. EPNs are also used as bioinsecticides, and so understanding their behaviour and biology could have broad benefits across industry and academia.

Responses of the entomopathogenic nematode,Steinernema riobraveto its insect hosts,Galleria mellonellaandTenebrio molitor

Parasitology ◽  
2007 ◽  
Vol 134 (6) ◽  
pp. 889-898 ◽  
Author(s):  
J. M. CHRISTEN ◽  
J. F. CAMPBELL ◽  
E. E. LEWIS ◽  
D. I. SHAPIRO-ILAN ◽  
S. B. RAMASWAMY
Keyword(s):  
Host Species ◽  
Post Infection ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Symbiotic Bacterium ◽  
Physiological Status ◽  
Post Injection ◽  
Significant Preference ◽  
Time Post Infection

SUMMARYPotential hosts for infective juveniles of entomopathogenic nematodes can vary considerably in quality based on the characteristics of the host species/stage, physiological status (e.g. stress, feeding on toxins), and infection status (heterospecific or conspecific infection). In this study, we investigated responses of the entomopathogenic nematodeSteinernema riobraveto hosts (Galleria mellonellaorTenebrio molitor) that were previously parasitized with conspecifics or injected with the nematode-symbiotic bacterium,Xenorhabdussp., to determine if there is a preference for previously parasitized/injected hosts and when this preference might occur. In no-choice bioassays, the number of juveniles infecting both host species decreased with increasing time post-infection. However, infective juveniles continued to infect previously parasitized hosts up to 72 h. Significant preference was exhibited byS. riobravefor 24 h post-infectionG. mellonellalarvae over uninfected, and by 24 h post-injectionG.mellonellalarvae over 48 h post-injection larvae. No significant preference was exhibited byS. riobraveforT. molitorhosts previously parasitized with conspecifics or those injected with bacteria in any treatment combination. Such preference for, or continued infection of parasitized insects, has the potential to impact nematode efficacy.

scholarly journals Transcriptional variation and divergence of host-finding behaviour in Steinernema carpocapsae infective juveniles

2018 ◽  
Author(s):  
Neil D. Warnock ◽  
Deborah Cox ◽  
Ciaran McCoy ◽  
Robert Morris ◽  
Johnathan J. Dalzell
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Expression Patterns ◽  
Host Finding ◽  
Steinernema Carpocapsae ◽  
Differentially Expressed ◽  
Infective Juvenile ◽  
Microrna Target

AbstractSteinernema carpocapsae is an entomopathogenic nematode that employs nictation and jumping behaviours to find host insects. 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). 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 isomiR variants 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. These data provide deeper insight to the transcriptional landscape of behavioural variation in S. carpocapsae, underpinning efforts to functionally dissect the parasite host-finding apparatus.Author summarySteinernema carpocapsae is a lethal parasite of insects. In order to find and invade a host insect, the S. carpocapsae infective juvenile will typically stand upright, waving its anterior in the air as it searches for host-specific cues. When the infective juvenile senses insect volatile compounds and movement (both signals are required), it will attempt to jump towards the source of those stimuli. Whilst the jumping behaviour is unique to Steinernema species nematodes, nictation is a host-finding behaviour shared with other important parasites of medical and veterinary importance. We have found that different strains of S. carpocpsae use modified host-finding strategies, and that these behavioural differences correlate with gene expression patterns, identifying genes that may be crucial in regulating aspects of host-finding. We also assessed the complement of microRNAs, which are small non-coding RNAs that regulate target gene expression. We found a surprising difference in the abundance of shared microRNAs between strains of S. carpocapsae; these differences also reveal expression differences that correlate with behavioural variation. Predicted microRNA target genes suggest that microRNA variation could significantly influence the behaviour of nematodes. Broadly, this study provides insight to the relationship between gene expression and behaviour, paving the way for detailed studies on gene function.

scholarly journals VIRULENCE OF ENTOMOPATHOGENIC NEMATODE TO PUPAE AND ADULTS OF Drosophila suzukii IN LABORATORY

2019 ◽  
Vol 21 (2) ◽  
pp. 126-138
Author(s):  
Andressa Lima de Brida ◽  
Silvia Renata Siciliano Wilcken ◽  
Luis Garrigós Leite ◽  
Flávio Roberto Mello Garcia
Keyword(s):  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Petri Dish ◽  
Rapid Expansion ◽  
Steinernema Feltiae ◽  
Control Treatment ◽  
Drosophila Suzukii ◽  
Climate Chamber ◽  
Randomized Design ◽  
Completely Randomized Design

Drosophila suzukii is considered one of the most important pests of fruit farming. Due to its rapid expansion, control alternatives of this fly should be investigated. The use of entomopathogenic nematodes (EPNs) represents an important tool in the control. This study aimed to evaluate the virulence of EPNs isolates in pupae and the repercussion in adults of D. suzukii in laboratory. The experiment was conducted in a completely randomized design with five treatments and five replicates. Each plot consisted of a Petri dish lined with two sheets of filter paper. The isolates Heterorhabditis amazonensis IBCBn 24, Heterorhabditis indica IBCBn 05, Steinernema carpocapsae IBCBn 02 and Steinernema feltiae IBCBn 47 were inoculated into 2 mL at the concentration of 1,000 infective juveniles IJs/mL. The control treatment consisted of 2 mL distilled water. After inoculation, five pupae of D. suzukii were placed in the Petri dishes, which were then sealed and stored in a BOD climate chamber at 26 ± 1ºC, 70 ± 10% RH in the dark. Assessments were performed daily until the emergence of adults. Dead pupae and adults were dissected for the observation and quantification of IJs. The isolates, H. indica IBCBn 05, H. amazonensis IBCBn 24, S. carpocapsae IBCBn 02 and S. feltiae IBCBn 47, infected and made unviable 35.0, 16.0, 13.0 and 43.0% in pupae and 47.0, 80.0, 84.0 and 57.0 % in adults of D. suzukii. H. indica IBCBn 05 obtained the highest number of IJs produced in pupae and adults, 35.0 and 125.0.

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