scholarly journals Potent Ant Deterrents Emitted from Nematode-Infected Insect Cadavers

Author(s):  
Geoffrey Jaffuel ◽  
Sribala Krishnamani ◽  
Ricardo A. R. Machado ◽  
Raquel Campos-Herrera ◽  
Ted C. J. Turlings

AbstractMost known species of entomopathogenic nematodes (EPNs) are generalist obligate parasites of insects. They kill their hosts within days after infection and mortality is mainly caused by toxins produced by bacteria that co-infect the hosts and serve as food for the nematodes. EPNs can infect a very broad spectrum of insects and these insects can therefore be expected to have evolved strategies to avoid infection. Indeed, ants are known to avoid feeding on EPN-infected insect cadavers, most likely because they are repelled by semiochemicals that emanate from the cadavers. The source and nature of these repellents are so far unknown. In a series of behavioral and chemical analytical experiments we identified hexadecanal and 2-heptadecanone as two compounds that are emitted by insect larva that are infected by the EPN Steinernema feltiae, but not by uninfected larvae. When spiking honey water with the two semiochemicals, they were confirmed to be highly deterrent to the ant Lasius niger. The environmentally benign hexadecanal and 2-heptadecanone could be employed to ward off ants and possibly other pests. Additional experiments are needed to fully determine their application potential.

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.


Nematology ◽  
2000 ◽  
Vol 2 (5) ◽  
pp. 515-521 ◽  
Author(s):  
Hara Menti ◽  
Denis Wright ◽  
Roland Perry

AbstractThe infectivity of populations of the entomopathogenic nematodes Steinernema feltiae and Heterorhabditis megidis from Greece (GR) and the UK was compared using Galleria mellonella larvae as hosts. Dose-response tests showed that the two Steinernema populations did not differ in their establishment rates but they were more infective than H. megidis UK 211. The temperature range for infectivity was greater than that for development. However, the optimal temperature for infection and development for all populations was 23°C. Infectivity of Steinernema populations was not affected by storage for 12 weeks. However, 12 week-old H. megidis UK 211 infective juveniles (IJ) were less infective than fresh IJ. H. megidis GR showed very low establishment rates at all the doses and temperatures tested, before and after storage. The results are discussed in relation to the nematodes' climatic origin and lipid content. Pouvoir infestant de populations des nématodes entomopathogènes Steinernema feltiae et Heterorhabditis megidis suivant la température, l'âge et le contenu lipidique - Le pouvoir infestant de populations des nématodes entomopathogènes Steinernema feltiae et Heterorhabditis megidis provenant de Grèce et du Royaume Uni a été comparée, utilisant comme hôte Galleria mellonella. Les tests de dose/réaction ont montré que les taux d'établissement des deux populations ne diffèrent pas mais que leur pouvoir infestant était plus élevée que celle de H. megidis UK211. La plage des températures permettant l'infestation était plus étendue que celle relative au développement. Cependant, les températures optimales pour l'infestation et pour le développement étaient l'une et l'autre de 23°C pour toutes les populations. L'infestivité des populations de Steinernema n'a pas été affectée par un stockage de 12 semaines. Les juvéniles infestants de H. megidis UK211 âgés de 12 semaines montraient toutefois une infestivité plus faible que celle d'individus frais. Les specimens de H. megidis provenant de Grèce présentaient - que ce soit avant ou après le stockage - des taux d'établissement très faibles pour toutes les doses et les températures testées. Ces résultats sont discutés en relation avec l'origine climatique et le contenu lipidique des nématodes.


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.


2020 ◽  
Vol 56 (No. 3) ◽  
pp. 214-225
Author(s):  
Magdalena Dzięgielewska ◽  
Iwona Adamska

In 2016-2018, in north-western Poland, field studies were carried out on the coexistence of various taxonomic groups, such as soil nematodes and fungi, including beneficial species that comprise the environment’s natural resistance to pests in agrocenoses. The research aimed to find a connection between select biotic and abiotic factors in the chosen crops which could have practical applications in plant protection. Entomopathogenic nematodes Steinernema feltiae Filipiev, 1934 and entomopathogenic fungi Cordyceps fumosorosea and Metarhizium anisopliae (Metschn.) Sorokin were found to be present in all studied agrocenoses; however, they showed clear preferences for some types of crops or soil. The research shows that the effectiveness of the biological methods of plant protection depends on the selection of the right biopreparations, which strengthen the local populations of the beneficial organisms present in specific agriculture areas.


2020 ◽  
Vol 6 (4) ◽  
pp. 359
Author(s):  
Jiří Nermuť ◽  
Jana Konopická ◽  
Rostislav Zemek ◽  
Michal Kopačka ◽  
Andrea Bohatá ◽  
...  

Entomopathogenic nematodes and fungi are globally distributed soil organisms that are frequently used as bioagents in biological control and integrated pest management. Many studies have demonstrated that the combination of biocontrol agents can increase their efficacy against target hosts. In our study, we focused on another potential benefit of the synergy of two species of nematodes, Steinernema feltiae and Heterorhabditis bacteriophora, and the fungus Isaria fumosorosea. According to our hypothesis, these nematodes may be able to disseminate this fungus into the environment. To test this hypothesis, we studied fungal dispersal by the nematodes in different arenas, including potato dextrose agar (PDA) plates, sand heaps, sand barriers, and glass tubes filled with soil. The results of our study showed, for the first time, that the spreading of both conidia and blastospores of I. fumosorosea is significantly enhanced by the presence of entomopathogenic nematodes, but the efficacy of dissemination is negatively influenced by the heterogeneity of the testing arena. We also found that H. bacteriophora spread fungi more effectively than S. feltiae. This phenomenon could be explained by the differences in the presence and persistence of second-stage cuticles or by different foraging behavior. Finally, we observed that blastospores are disseminated more effectively than conidia, which might be due to the different adherence of these spores (conidia are hydrophobic, while blastospores are hydrophilic). The obtained results showed that entomopathogenic nematodes (EPNs) can enhance the efficiency of fungal dispersal.


Nematology ◽  
2008 ◽  
Vol 10 (2) ◽  
pp. 251-259 ◽  
Author(s):  
Ernesto San-Blas ◽  
Barbara Pembroke ◽  
Simon Gowen

AbstractEntomopathogenic nematodes are able to survive by scavenging. We tested Steinernema feltiae, S. affine and Heterorhabditis megidis alone or in different combinations to evaluate the responses of these nematodes when dead or live Galleria mellonella larvae were offered. Steinernema feltiae and S. affine scavenged upon dead G. mellonella larvae and about 30% more dead larvae were penetrated than live ones. By contrast, H. megidis penetrated more live larvae than dead ones. When the nematode species were combined, the results varied among the combinations, but the dead larvae were always used as a host. The behaviour of natural field populations of S. feltiae and S. affine was also compared. Steinernema feltiae showed no difference between scavenging and performing 'normal infections', whereas S. affine scavenged to a reduced amount (around 60% less); this difference could be related to the particular foraging strategy of these nematodes.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fouad Mokrini ◽  
Salah-Eddine Laasli ◽  
Youssef Benseddik ◽  
Abdelmalek Boutaleb Joutei ◽  
Abdelali Blenzar ◽  
...  

Abstract The Mediterranean fruit fly, Ceratitis capitata Wiedemann, is a deleterious pest worldwide affecting fruit production. The entomopathogenic nematodes (EPNs) are a potential biocontrol agent that could be effectively used to control this Mediterranean fruit fly. In this study, five EPN strains reported from different fields in Morocco were evaluated for their efficacy against C. capitata. In laboratory assays, Steinernema feltiae-SF-MOR9, S. feltiae-SF-MOR10 and Heterorhabditis bacteriophora-HB-MOR7 strains showed significantly higher infectivity and penetration rates when compared to the other strains. S. feltiae-SF-MOR9 caused the highest larval mortality rate (80%) at 50 infective juveniles (IJs) cm−2. However, additional results showed that both S. feltiae strains were significantly effective in controlling C. capitata larvae in apricot (Prunus armeniaca) fruits on soil surface with high mortality rate at 50 and 100 IJs cm−2. Different soil textures and moisture levels resulted in a significant variation in EPN strain virulence against C. capitata. Sandy clay loam soil in combination with 50 IJs cm−2 of S. feltiae (SF-MOR9 or SF-MOR10) caused a higher mortality rate of C. capitata larvae. Furthermore, applying these EPN strains at 50–100 IJs cm−2 in combination with 10–15% moisture level showed optimal results against C. capitata larvae. Therefore, those two Moroccan EPN strains could be used as promising eco-friendly biological agents against C. capitata.


Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 388
Author(s):  
Anna Mazurkiewicz ◽  
Dorota Tumialis ◽  
Magdalena Jakubowska

The largest group of cabbage plant pests are the species in the owlet moth family (Lepidoptera: Noctuidae), the most dangerous species of which is the cabbage moth (Mamestra brassicae L.). In cases of heavy infestation by this insect, the surface of plants may be reduced to 30%, with a main yield loss of 10–15%. The aim of the present study was to assess the susceptibility of M. brassicae larvae to nine native nematode isolates of the species Steinernema feltiae (Filipjev) and Heterorhabditis megidis Poinar, Jackson and Klein under laboratory conditions. The most pathogenic strains were S. feltiae K11, S. feltiae K13, S. feltiae ZAG11, and S. feltiae ZWO21, which resulted in 100% mortality at a temperature of 22 °C and a dosage of 100 infective juveniles (IJs)/larva. The least effective was H. megidis Wispowo, which did not exceed 35% mortality under any experimental condition. For most strains, there were significant differences (p ≤ 0.05) in the mortality for dosages between 25 IJs and 50 IJs, and between 25 IJs and 100 IJs, at a temperature of 22 °C. Statistical analysis of the effect of temperature on mortality showed that only strain H. megidis Wipsowo exhibited significant differences (p ≤ 0.05) when applied at dosages of 50 IJs and 100 IJs.


Nematology ◽  
2010 ◽  
Vol 12 (6) ◽  
pp. 915-928 ◽  
Author(s):  
Steve Edgington ◽  
Alan G. Buddie ◽  
Dave Moore ◽  
Andrés France ◽  
Loreto Merino ◽  
...  

Abstract A systematic programme of surveys for entomopathogenic nematodes (EPN) was done in Chile between 2006 and 2008. The survey spanned the principal ecosystems of mainland Chile as well as a number of islands, and covered a wide range of habitats including the Atacama Desert, Andean Altiplano, temperate rainforests and subpolar territory. Nearly 1400 soil samples were collected, of which 7% were positive for EPN. Of 101 EPN isolates obtained, 94 were Steinernema spp. and seven were Heterorhabditis sp. Of the 94 Steinernema isolates, 39 were identified as Steinernema feltiae, the remainder being distributed between two new species, S. unicornum (52 records) and S. australe (three records). The Heterorhabditis isolates, all designated as Heterorhabditis sp.1, are referred to herein as H. cf. safricana. Steinernema feltiae and S. unicornum were collected predominately in the south of Chile and were obtained from a range of habitats, including forests, open grassland, montane soils and coastal zones; neither species was recovered from the far north of the country (viz., desert soils in the Norte Grande region). Steinernema australe was found in only three soil samples, all from humid, cool, coastal localities in the south. Heterorhabditis cf. safricana was recovered from the northern regions, with most isolates found in or on the periphery of the Atacama Desert; they were not recovered from cooler, more humid regions of southern Chile. Molecular information indicated there were two subgroups of both S. unicornum and S. feltiae, with a geographical, intraspecific split of subgroups between the most southerly and the more central survey zones. All isolates were collected by ex situ baiting with waxmoth larvae and the natural hosts are unknown.


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