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Perier JD, Kaplan F, Lewis EE, Alborn H, Schliekelman P, Toews MD, Schiller KC, Shapiro-Ilan DI. Enhancing entomopathogenic nematode efficacy with Pheromones: A field study targeting the pecan weevil. J Invertebr Pathol 2024; 203:108070. [PMID: 38311231 DOI: 10.1016/j.jip.2024.108070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/17/2024] [Accepted: 01/19/2024] [Indexed: 02/10/2024]
Abstract
Consistent efficacy is required for entomopathogenic nematodes to gain wider adoption as biocontrol agents. Recently, we demonstrated that when exposed to nematode pheromone blends, entomopathogenic nematodes showed increased dispersal, infectivity, and efficacy under laboratory and greenhouse conditions. Prior to this study, the impact of entomopathogenic nematode-pheromone combinations on field efficacy had yet to be studied. Steinernema feltiae is a commercially available entomopathogenic nematode that has been shown to increase mortality in insect pests such as the pecan weevil Curculio caryae. In this study, the pecan weevil was used as a model system to evaluate changes in S. feltiae efficacy when treated with a partially purified ascaroside pheromone blend. Following exposure to the pheromone blend, the efficacy of S. feltiae significantly increased as measured with decreased C. caryae survival despite unfavorable environmental conditions. The results of this study highlight a potential new avenue for using entomopathogenic nematodes in field conditions. With increased efficacy, using entomopathogenic nematodes will reduce reliance on conventional management methods in pecan production, translating into more environmentally acceptable practices.
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Affiliation(s)
- Jermaine D Perier
- Department of Entomology, University of Georgia, Tifton, GA 31793, United States
| | - Fatma Kaplan
- Pheronym, Inc., Woodland, CA 95695, United States
| | - Edwin E Lewis
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, United States
| | - Hans Alborn
- USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL 32608, United States
| | - Paul Schliekelman
- Department of Statistics, University of Georgia, Athens, GA 30602, United States
| | - Michael D Toews
- Department of Entomology, University of Georgia, Tifton, GA 31793, United States
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2
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Mendez P, Walsh B, Hallem EA. Using newly optimized genetic tools to probe Strongyloides sensory behaviors. Mol Biochem Parasitol 2022; 250:111491. [PMID: 35697205 PMCID: PMC9339661 DOI: 10.1016/j.molbiopara.2022.111491] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/25/2022] [Accepted: 06/07/2022] [Indexed: 11/26/2022]
Abstract
The oft-neglected human-parasitic threadworm, Strongyloides stercoralis, infects roughly eight percent of the global population, placing disproportionate medical and economic burden upon marginalized communities. While current chemotherapies treat strongyloidiasis, disease recrudescence and the looming threat of anthelminthic resistance necessitate novel strategies for nematode control. Throughout its life cycle, S. stercoralis relies upon sensory cues to aid in environmental navigation and coordinate developmental progression. Odorants, tastants, gases, and temperature have been shown to shape parasite behaviors that drive host seeking and infectivity; however, many of these sensory behaviors remain poorly understood, and their underlying molecular and neural mechanisms are largely uncharacterized. Disruption of sensory circuits essential to parasitism presents a promising strategy for future interventions. In this review, we describe our current understanding of sensory behaviors - namely olfactory, gustatory, gas sensing, and thermosensory behaviors - in Strongyloides spp. We also highlight the ever-growing cache of genetic tools optimized for use in Strongyloides that have facilitated these findings, including transgenesis, CRISPR/Cas9-mediated mutagenesis, RNAi, chemogenetic neuronal silencing, and the use of fluorescent biosensors to measure neuronal activity. Bolstered by these tools, we are poised to enter an era of rapid discovery in Strongyloides sensory neurobiology, which has the potential to shape pioneering advances in the prevention and treatment of strongyloidiasis.
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Affiliation(s)
- Patricia Mendez
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA; Molecular Biology Interdepartmental PhD Program, University of California Los Angeles, Los Angeles, CA, USA.
| | - Breanna Walsh
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA; Molecular Biology Interdepartmental PhD Program, University of California Los Angeles, Los Angeles, CA, USA; Medical Scientist Training Program, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, USA.
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3
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Gilbert R, Uetz GW. Infection influences vibratory signal components in a wolf spider. Ethology 2022. [DOI: 10.1111/eth.13319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rachel Gilbert
- Department of Biological Sciences University of Cincinnati Cincinnati Ohio USA
- NASA Ames Research Center Mountain View California USA
| | - George W. Uetz
- Department of Biological Sciences University of Cincinnati Cincinnati Ohio USA
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4
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Influence of the ascarosides on the recovery, yield and dispersal of entomopathogenic nematodes. J Invertebr Pathol 2022; 188:107717. [PMID: 35031295 DOI: 10.1016/j.jip.2022.107717] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/08/2022] [Accepted: 01/09/2022] [Indexed: 11/23/2022]
Abstract
Recovery, yield, and dispersal are crucial developmental and behavioral indices for the infective juveniles of entomopathogenic nematodes, which are used as biocontrol agents against a variety of agricultural pests. Ascarosides and isopropylstilbene (ISO) function as nematode pheromones with developmental and behavioral effects. In this study, 11 synthesized ascarosides identified from Caenorhabditis elegans, together with ISO identified from Photorhabdus luminescens, were used to determine their influence on the IJ recovery, growth on agar plates, and dispersal of S. carpocapsae All, H. bacteriophora H06 and H. indica LN2 nematodes. Compared with the controls, significant differences in IJ recovery of three nematode species were detected from the supernatants of their corresponding bacterial cultures with almost all ascarosides or isopropylstilbene (ISO) at 0.04 nM in 6 days. The highest IJ recovery percentages was obtained from ISO and ascr#3 for All strain, ascr#5 and ascr#6 for LN2 strain, and ISO and ascr#12 for H06 strain. The ISO detected from Photorhabdus bacteria also induced IJ recovery of S. carpocapsae All. IJ yields was significantly stimulated by all synthesized compounds for S. carpocapsae All, and by most compounds for H. bacteriophora H06. The higher IJ yields varied with ascarosides. Ascr#7 and DMSO was common for the improved IJ yields of both nematode species. The three nematode species showed marked differences in dispersal behavior. In response to the ascarosides or ISO, S. carpocapsae All IJs actively moved with different dispersal rates, H. indica LN2 IJs in very low dispersal rates, and H. bacteriophora H06 IJs in variable and even suppressed rates on the agar plates at least during the assay period. Based on the synthesized standards, ascr#1, ascr#9 and ascr#10 were detected from three nematode species, ascr#5 and ascr#11 also from S. carpocapsae All and H. bacteriophora H06, and ascr#12 also from H. bacteriophora H06 and H. indica LN2. Ascr#9 was most abundant in three nematode species. Compared with the sterile PBS, significantly more ascr#1, ascr#9 and ascr#10 were detected from S. carpocapsae All and H. indica LN2, but less ascr#5 and ascr#11 from S. carpocapsae All, ascr#1, ascr#5, ascr#11 and ascr#12 from H. bacteriophora H06, in the corresponding bacterial supernatant. It seems that the bacterial supernatants could regulate the ascaroside secretion by the three nematode species. These results will provide useful clues for selecting suitable ascarosides to induce the recovery, improve the yield, and enhance the dispersal of the IJs of these nematodes.
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Katsis AC, Colombelli-Négrel D, Common LK, O’connor JA, Dudaniec RY, García-Loor J, Kleindorfer S. Nestling behaviour predicts naris deformation in Darwin’s finches parasitized by the avian vampire fly. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Although in-nest parasitism can reduce the fitness of avian hosts, the severity of these effects may vary with host physiology and behaviour. If certain nestling behaviours are beneficial for resisting parasitism, then selection may favour some behavioural phenotypes over others. Here, we tested whether differences in nestling behaviour mediate the negative effects of parasitism, using small ground finches (Geospiza fuliginosa), on Floreana Island, that had been parasitized by the invasive avian vampire fly (Philornis downsi). We first established, using 4 years of breeding data (2005, 2006, 2010 and 2020), that nestlings exposed to more parasites had larger nares and, among older nestlings only, lower body mass. We then examined, using data from the 2020 season, whether each nestling’s behaviour (specifically, its response to human handling) predicted the severity of its naris deformation. When faced with high-intensity parasitism, more responsive nestlings (i.e. those that struggled more during handling) had larger nares compared to more docile nestlings. This suggests that more responsive nestlings suffer greater fitness costs due to parasitism, although we also discuss alternative explanations. Future work should consider the stability and heritability of these nestling behavioural differences and whether parasite-induced selection shapes behavioural variation at the population level.
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Affiliation(s)
- Andrew C Katsis
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Diane Colombelli-Négrel
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Lauren K Common
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Jody A O’connor
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
- Department for Environment and Water, Government of South Australia, Adelaide, South Australia, Australia
| | - Rachael Y Dudaniec
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | | | - Sonia Kleindorfer
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
- Konrad Lorenz Research Centre for Behaviour and Cognition and Department of Behavioural and Cognitive Biology, University of Vienna, Vienna, Austria
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Zart M, de Macedo MF, Simões Santos Rando J, Doneze GS, Brito CP, de Souza Poletto R, Alves VS. Performance of entomopathogenic nematodes on the mealybug, Dysmicoccus brevipes (Hemiptera: Pseudococcidae) and the compatibility of control agents with nematodes. J Nematol 2021; 53:e2021-020. [PMID: 33860237 PMCID: PMC8039974 DOI: 10.21307/jofnem-2021-020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Indexed: 11/21/2022] Open
Abstract
The performance of nine isolates of Heterorhabditis amazonensis and one of Heterorhabditis indica on the mealybug Dysmicoccus brevipes, (Hemiptera: Pseudococcidae), were evaluated. The most virulent isolates were evaluated for nematode vertical and horizontal dispersal, and for efficiency at concentrations of 0 (control), 25, 50, 75, and 100 infective juveniles (IJs)/cm2 on adult females of the insect. A compatibility assessment was also carried out with commercial products, registered or in the process of registration, for use in the cassava culture. The isolates that caused the highest mortality rate of D. brevipes were NEPET11 (93.8% ± 4.1) and IBCB-n40 (84.0% ± 8.1), both isolates of Heterorhabditis amazonensis, while the isolate NEPET11 was more virulent than IBCB-n40 at all concentrations evaluated. In the dispersal test, the NEPET11 isolate caused mortality in the mealybug at a depth of up to 20 cm and a horizontal displacement of 7.25 cm. In the compatibility test, the NEPET11 isolate exhibited reduced viability due to the products Poquer, Tiguer 100 EC, Actara 250 WG, and Gaucho FS. The insecticide Curyom 550 EC was the only one that reduced infectivity (reduction of 92%) and is the only product classified as moderately toxic, while all the others were classified as compatible based on E%.
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Affiliation(s)
- Marcelo Zart
- Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, IFRS, Ibirubá, Rio Grande do Sul, Brazil
| | | | - Jael Simões Santos Rando
- Universidade Estadual do Norte do Paraná, Laboratório de Entomologia e Nematologia, Bandeirantes, Brazil
| | - Gabriela Souza Doneze
- Universidade Estadual do Norte do Paraná, Laboratório de Entomologia e Controle Microbiano (LECOM), Cornélio Procópio, Paraná, Brazil
| | - Cassia Pereira Brito
- Universidade Estadual do Norte do Paraná, Laboratório de Entomologia e Controle Microbiano (LECOM), Cornélio Procópio, Paraná, Brazil
| | - Rodrigo de Souza Poletto
- Universidade Estadual do Norte do Paraná, Laboratório Interdisciplinar de Pesquisa e Ensino de Botânica e Educação Ambiental (LIPEBEA), Cornélio Procópio, Paraná, Brazil
| | - Viviane Sandra Alves
- Universidade Estadual do Norte do Paraná, Laboratório de Entomologia e Controle Microbiano (LECOM), Cornélio Procópio, Paraná, Brazil
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Behavioral and molecular response of the insect parasitic nematode Steinernema carpocapsae to cues emitted by a host, the red palm weevil, Rhynchophorus ferrugineus. Mol Biochem Parasitol 2020; 241:111345. [PMID: 33290763 DOI: 10.1016/j.molbiopara.2020.111345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 11/14/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022]
Abstract
As the larvae of the date palm pest, the red palm weevil, Rhynchophorus ferrugineus, feeds on the host tissue, they emit a distinctive sound which can be recorded outside of the infected tree. We evaluated the response of infective juveniles (IJs) of the entomopathogenic nematodes Steinernema carpocapsae to the R. ferrugineus larvae and it's sound source, separately. In the presence of the insect larvae, 50.2 % of total IJs moved toward those larvae. Recorded insect larvae sound emitted by the speaker resulted in 7% of total IJs near the sound source. RNA-Seq data indicated that more genes were downregulated in S. carpocapsae IJs exposed to insect and speaker compared to non-stimulated IJs. IJs exposed to insect exhibited more up-regulated genes than IJs exposed to speaker. Enriched pathways and biological processes in IJs were similar for both stimuli. The inhibition of locomotion, regulation of neurotransmitter secretion, response to biotic stimulus, and cellular response to chemical stimuli were enriched with unique GO terms for speaker treatment. The regulation of localization, sodium ion transmembrane transport, regulation of response to stress and response to organic substances were the GO categories enriched unique to insect. The host-parasitic interaction was regulated by the differential expression of Ras/MAP kinase, TGF-beta signaling, insulin signaling, AMPK signaling, PPAR signaling pathways and many developmental pathways. More prominent R. ferrugineus host localization by S. carpocapsae was primarily due to the differential transcriptional regulation of olfactory signal transduction, FOXO-family proteins, calcium signaling, WNT and mTOR signaling pathway. The neural basis for the nematode attraction to insect host is based on the chemosensation and the mechanosensation. Many neuropeptides and neuromodulators are involved in regulating the foraging behavior of S. carpocapsae. The results of this study provide new insights into the molecular mechanisms that allow these nematodes to seek insect hosts. Our finding, especially the molecular ones suggest that chemical cues emitted by the active insect host are stimulants of nematodes attraction. Whereas the sound emitted by the insect has minor effects on the nematode behavior.
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8
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Conspecific and heterospecific pheromones stimulate dispersal of entomopathogenic nematodes during quiescence. Sci Rep 2020; 10:5738. [PMID: 32235877 PMCID: PMC7109026 DOI: 10.1038/s41598-020-62817-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 03/18/2020] [Indexed: 01/21/2023] Open
Abstract
Ascaroside pheromones stimulate dispersal, a key nematode behavior to find a new food source. Ascarosides produced by entomopathogenic nematodes (EPNs) drive infective juvenile (IJ) emergence from consumed cadavers and dispersal in soil. Without ascarosides from host cadavers, Steinernema feltiae (EPN) reduce dispersal substantially. To determine whether other Steinernema spp. exhibit the same behavior, we compared S. feltiae and S. carpocapsae IJs without host cadaver pheromones. Unlike S. feltiae, S. carpocapsae IJs continued to disperse. However, S. carpocapsae IJs exhibited a temperature-dependent quiescent period. The IJ quiescent period increased at ≤20 °C but did not appear at ≥25 °C. Consistent with this, S. carpocapsae IJ quiescence increased from 30 min to 24 h at ≤20 °C over 60 days. The quiescent period was overcome by dispersal pheromone extracts of their own, other Steinernema spp. and Heterorhabditis spp. Furthermore, S. carpocapsae IJ ambush foraging associated behaviors (tail standing, waving, and jumping) were unaffected by the absence or presence of host cadaver pheromones. For S. feltiae, IJ dispersal declined at all temperatures tested. Understanding the interaction between foraging strategies and pheromone signals will help uncover molecular mechanisms of host seeking, pathogenicity and practical applications to improve the EPN’s efficacy as biocontrol agents.
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Virant-Doberlet M, Kuhelj A, Polajnar J, Šturm R. Predator-Prey Interactions and Eavesdropping in Vibrational Communication Networks. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00203] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Oliveira-Hofman C, Kaplan F, Stevens G, Lewis E, Wu S, Alborn HT, Perret-Gentil A, Shapiro-Ilan DI. Pheromone extracts act as boosters for entomopathogenic nematodes efficacy. J Invertebr Pathol 2019; 164:38-42. [PMID: 31034842 DOI: 10.1016/j.jip.2019.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 11/17/2022]
Abstract
Inconsistency in entomopathogenic nematode (EPN) efficacy is still one of the biggest challenges for the wider adoption of EPNs as biocontrol agents. Previous studies demonstrated that extracts from EPN-infected hosts enhance dispersal and efficacy, two key factors in success of EPNs. Some active components in the insect host cadavers responsible for dispersal, ascarosides, have been identified as nematode pheromones. We hypothesized that pheromone extracts increase dispersal of EPN infective juveniles (IJs) leading to increased efficacy. First, we determined whether pheromone extracts improved IJ movement/dispersal in soil columns baited with Tenebrio molitor larvae. We found that pheromone extracts induced higher numbers of Steinernema carpocapsae and Steinernema feltiae IJs to move towards T. molitor larvae in the bottom of the column compared to IJs treated with infected cadaver macerate and water, positive and negative controls, respectively. Furthermore, the number of S. carpocapsae IJs that invaded T. molitor larvae was higher for the pheromone extract treatment than the controls. S. feltiae IJs that were pretreated with pheromone extracts and macerate (positive control) infected T. molitor at the same rate but invasion was superior to IJs that were treated with water. Consistent with the soil column tests, both S. carpocapsae and S. feltiae IJs treated with pheromone extracts performed better in killing larvae of two economically important insect larvae, pecan weevil, Curculio caryae, and black soldier fly, Hermetia illucens, in greenhouse tests compared to IJs treated with water. We demonstrated pheromone-mediated behavioral manipulation of a biological control agent to enhance pest control potential. Conceivably, nematodes can be exposed to efficacy-enhancing pheromones prior to field application.
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Affiliation(s)
| | | | - Glen Stevens
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, USA
| | - Edwin Lewis
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, USA
| | | | - Hans T Alborn
- USDA-ARS Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL 32608, USA
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11
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Li C, Zhou X, Lewis EE, Yu Y, Wang C. Study on host-seeking behavior and chemotaxis of entomopathogenic nematodes using Pluronic F-127 gel. J Invertebr Pathol 2019; 161:54-60. [PMID: 30707919 DOI: 10.1016/j.jip.2019.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/31/2018] [Accepted: 01/26/2019] [Indexed: 10/27/2022]
Abstract
Pluronic F-127 gel (PF127) has proven to be a powerful medium in which to study host-finding behavior and chemotaxis for plant-parasitic nematodes. Pluronic gel can also be used to study host-habitat seeking behavior of entomopathogenic nematodes (EPN), which are natural enemies of root-feeding insect pests. In this study, PF127 was used to study tritrophic interactions among EPNs, host-habitat roots and insects. We also tested whether EPN aggregated to acetic acid (pH gradient) which mimicked the conditions near the roots. The chive root gnat Bradysia odoriphaga alone significantly attracted more nematodes than chive roots alone or the combination of roots plus insects. The attractiveness of B. odoriphaga differed (3.7-15.4%) among all tested species/strains of EPNs. In addition, we found that Heterorhabditis spp. and Steinernema spp. infective juveniles responded to pH gradients formed by acetic acid in Pluronic gel. The preferred pH ranges for strains of H. bacteriophora and H. megidis were from 4.32-5.04, and from 5.37-6.92 for Steinernema species, indicating that Heterorhabditis spp. prefer low pH conditions than Steinernema species. A narrow pH gradient between 6.84 and 7.05 was detected around chive root tips in which EPN was attracted. These results suggest that Pluronic gel can be broadly used for the study of host or host-habitat seeking behaviors and chemotaxis of nematodes.
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Affiliation(s)
- Chunjie Li
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
| | - Xianhong Zhou
- Shandong Key Laboratory of Plant Virology, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Edwin E Lewis
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, USA
| | - Yi Yu
- Shandong Key Laboratory of Plant Virology, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
| | - Congli Wang
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China.
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12
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Baiocchi T, Braun L, Dillman AR. Touch-stimulation increases host-seeking behavior in Steinernema Carpocapsae. J Nematol 2019; 51:1-5. [PMID: 31814369 PMCID: PMC6909391 DOI: 10.21307/jofnem-2019-067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Indexed: 11/20/2022] Open
Abstract
Previous research demonstrated that Steinernema carpocapsae infective juveniles (IJs) exposed to a host cuticle were more attracted toward certain host-associated volatile odors. We wanted to test the specificity of attraction that results from exposure to host cuticle. Host recognition behavior was analyzed after stimulating IJs by allowing them to physically interact with Galleria mellonella cuticles. The subsequent behavioral response and the proportion of the population participating in chemotaxis to multiple host odors were measured. We found that exposure to host cuticles resulted in a significantly higher percentage of the population participating in host-seeking behavior, with threefold more nematodes participating in chemotaxis. We tested whether exposure to live or dead host cuticle resulted in a different response and found that a higher percentage of IJs exposed to a live host cuticle participated in chemotaxis than IJs exposed to a dead host cuticle, but that IJs exposed to a dead host demonstrated significantly higher participation than was observed for non-stimulated IJs. To test whether the increase in IJ participation in host-seeking behaviors after exposure to a live host cuticle was specific, we exposed stimulated IJs to a known repulsive odor, a neutral odor, and two predicted attractants. We found that stimulation of IJs through physical contact with a host cuticle induces a specific enhancement of host-seeking behavior to host-specific odors rather than a general increased chemotactic response to all volatile stimuli. However, the nematodes displayed an enhanced response to multiple host-specific odors. Future work should focus on the mechanism through which contact with live host cuticle stimulates increased behavioral response.
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Affiliation(s)
- Tiffany Baiocchi
- Department of Nematology, University of California Riverside , Riverside, CA, 92521
| | - Lauren Braun
- Department of Nematology, University of California Riverside , Riverside, CA, 92521
| | - Adler R Dillman
- Department of Nematology, University of California Riverside , Riverside, CA, 92521
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13
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Wu S, Kaplan F, Lewis E, Alborn HT, Shapiro-Ilan DI. Infected host macerate enhances entomopathogenic nematode movement towards hosts and infectivity in a soil profile. J Invertebr Pathol 2018; 159:141-144. [DOI: 10.1016/j.jip.2018.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/09/2018] [Accepted: 10/15/2018] [Indexed: 11/30/2022]
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14
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Holbrook RI, Mortimer B. Vibration sensitivity found in Caenorhabditis elegans. ACTA ACUST UNITED AC 2018; 221:jeb.178947. [PMID: 29903836 DOI: 10.1242/jeb.178947] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/11/2018] [Indexed: 01/10/2023]
Abstract
Mechanical sensing is important for all organisms, but is the least understood of the senses. As mechanical stimuli come in diverse forms, organisms often have sensors or sensory systems that specialise in a form of mechanical stimuli, such as touch or vibration. Here, we tested the hypothesis that the nematode worm Caenorhabditis elegans exhibits a behavioural response to vibration that is distinct from its responses to touch. We show that wild-type strain worms respond to sustained low-frequency vibration in a manner distinct from the known responses to non-localised mechanical stimuli. Furthermore, the behavioural responses of mutant strains suggest different roles for ciliated versus non-ciliated neurons in mediating the response. Although further study is required to identify the vibration-sensing pathway, our data support that C. elegans can sense substrate-borne vibrations using cells distinct from those used in gentle touch.
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Affiliation(s)
- Robert I Holbrook
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.,School of Computing, Faculty of Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - Beth Mortimer
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK .,Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
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15
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Labaude S, Griffin CT. Transmission Success of Entomopathogenic Nematodes Used in Pest Control. INSECTS 2018; 9:insects9020072. [PMID: 29925806 PMCID: PMC6023359 DOI: 10.3390/insects9020072] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/15/2018] [Accepted: 06/18/2018] [Indexed: 11/16/2022]
Abstract
Entomopathogenic nematodes from the two genera Steinernema and Heterorhabditis are widely used as biological agents against various insect pests and represent a promising alternative to replace pesticides. Efficacy and biocontrol success can be enhanced through improved understanding of their biology and ecology. Many endogenous and environmental factors influence the survival of nematodes following application, as well as their transmission success to the target species. The aim of this paper is to give an overview of the major topics currently considered to affect transmission success of these biological control agents, including interactions with insects, plants and other members of the soil biota including conspecifics.
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Affiliation(s)
- Sophie Labaude
- Department of Biology, Maynooth University, W23 A023 Maynooth, Co. Kildare, Ireland.
| | - Christine T Griffin
- Department of Biology, Maynooth University, W23 A023 Maynooth, Co. Kildare, Ireland.
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Lok JB. Signaling in Parasitic Nematodes: Physicochemical Communication Between Host and Parasite and Endogenous Molecular Transduction Pathways Governing Worm Development and Survival. CURRENT CLINICAL MICROBIOLOGY REPORTS 2016; 3:186-197. [PMID: 28781934 PMCID: PMC5543980 DOI: 10.1007/s40588-016-0046-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Signaling or communication between host and parasite may occur over relatively long ranges to enable host finding and acquisition by infective parasitic nematode larvae. Innate behaviors in infective larvae transmitted from the soil that enhance the likelihood of host contact, such as negative geotaxis and hypermotility, are likely mediated by mechanoreception and neuromuscular signaling. Host cues such as vibration of the substratum, elevated temperature, exhaled CO2, and other volatile odorants are perceived by mechanosensory and chemosensory neurons of the amphidial complex. Beyond this, the molecular systems that transduce these external cues within the worm are unknown at this time. Overall, the signal transduction mechanisms that regulate switching between dauer and continuous reproductive development in Caenorhabditis elegans, and doubtless other free-living nematodes, have provided a useful framework for testing hypotheses about how the morphogenesis and development of infective parasitic nematode larvae and the lifespan of adult parasites are regulated. In C. elegans, four major signal transduction pathways, G protein-coupled receptor signaling, insulin/insulin-like growth factor signaling, TGFβ-like signaling and steroid-nuclear hormone receptor signaling govern the switch between dauer and continuous development and regulate adult lifespan. Parasitic nematodes appear to have conserved the functions of G-protein-coupled signaling, insulin-like signaling and steroid-nuclear hormone receptor signaling to regulate larval development before and during the infective process. By contrast, TGFβ-like signaling appears to have been adapted for some other function, perhaps modulation of the host immune response. Of the three signal transduction pathways that appear to regulate development in parasitic nematodes, steroid-nuclear hormone signaling is the most straightforward to manipulate with administered small molecules and may form the basis of new chemotherapeutic strategies. Signaling between parasites and their hosts' immune systems also occurs and serves to modulate these responses to allow chronic infection and down regulate acute inflammatory responses. Knowledge of the precise nature of this signaling may form the basis of immunological interventions to protect against parasitism or related lesions and to alleviate inflammatory diseases of various etiologies.
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Affiliation(s)
- James B Lok
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104 USA
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Van Damme VM, Beck BK, Berckmoes E, Moerkens R, Wittemans L, De Vis R, Nuyttens D, Casteels HF, Maes M, Tirry L, De Clercq P. Efficacy of entomopathogenic nematodes against larvae of Tuta absoluta in the laboratory. PEST MANAGEMENT SCIENCE 2016; 72:1702-1709. [PMID: 26620187 DOI: 10.1002/ps.4195] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 11/15/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND Previous studies have indicated the control potential of entomopathogenic nematodes (EPNs) against Tuta absoluta. Here, the potential of Steinernema feltiae, S. carpocapsae and Heterorhabditis bacteriophora is studied when applied against larvae of T. absoluta inside leaf mines in tomato leaf discs by means of an automated spray boom. RESULTS The studied EPN species were effective against all four larval instars of T. absoluta but caused higher mortality in the later instars (e.g. fourth instar: 77.1-97.4% mortality) than in the first instars (36.8-60.0% mortality). Overall, S. feltiae and S. carpocapsae yielded better results than H. bacteriophora. Steinernema carpocapsae and H. bacteriophora performed better at 25 °C (causing 55.3 and 97.4% mortality respectively) than at 18 °C (causing 12.5 and 34.2% mortality respectively), whereas S. feltiae caused 100% mortality at both temperatures. Under optimal spraying conditions and with the use of Addit and Silwet L-77 adjuvants, a reduced dosage of 6.8 infective juveniles (IJs) cm(-2) yielded equally good control as a recommended dosage of 27.3 IJs cm(-2) . CONCLUSION Under laboratory conditions, S. feltiae and S. carpocapsae showed good potential against the larvae of T. absoluta inside tomato leaf mines. Results need to be confirmed in greenhouse experiments. © 2015 Society of Chemical Industry.
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Affiliation(s)
- Veerle M Van Damme
- Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Bert Keg Beck
- Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium
| | - Els Berckmoes
- Research Station for Vegetable Production, Sint-Katelijne-Waver, Belgium
| | - Rob Moerkens
- Tomato Research, Research Centre Hoogstraten, Hoogstraten, Belgium
| | - Lieve Wittemans
- Research Station for Vegetable Production, Sint-Katelijne-Waver, Belgium
| | - Raf De Vis
- Research Station for Vegetable Production, Sint-Katelijne-Waver, Belgium
| | - David Nuyttens
- Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium
| | - Hans F Casteels
- Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium
| | - Martine Maes
- Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium
| | - Luc Tirry
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Patrick De Clercq
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
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Gang SS, Hallem EA. Mechanisms of host seeking by parasitic nematodes. Mol Biochem Parasitol 2016; 208:23-32. [PMID: 27211240 DOI: 10.1016/j.molbiopara.2016.05.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 10/21/2022]
Abstract
The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors.
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Affiliation(s)
- Spencer S Gang
- Department of Microbiology, Immunology, and Molecular Genetics and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, United States.
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, United States.
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Lee JH, Dillman AR, Hallem EA. Temperature-dependent changes in the host-seeking behaviors of parasitic nematodes. BMC Biol 2016; 14:36. [PMID: 27154502 PMCID: PMC4858831 DOI: 10.1186/s12915-016-0259-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 04/22/2016] [Indexed: 01/08/2023] Open
Abstract
Background Entomopathogenic nematodes (EPNs) are lethal parasites of insects that are of interest as biocontrol agents for insect pests and disease vectors. Although EPNs have been successfully commercialized for pest control, their efficacy in the field is often inconsistent for reasons that remain elusive. EPN infective juveniles (IJs) actively search for hosts to infect using a diverse array of host-emitted odorants. Here we investigate whether their host-seeking behavior is subject to context-dependent modulation. Results We find that EPN IJs exhibit extreme plasticity of olfactory behavior as a function of cultivation temperature. Many odorants that are attractive for IJs grown at lower temperatures are repulsive for IJs grown at higher temperatures and vice versa. Temperature-induced changes in olfactory preferences occur gradually over the course of days to weeks and are reversible. Similar changes in olfactory behavior occur in some EPNs as a function of IJ age. EPNs also show temperature-dependent changes in their host-seeking strategy: IJs cultured at lower temperatures appear to more actively cruise for hosts than IJs cultured at higher temperatures. Furthermore, we find that the skin-penetrating rat parasite Strongyloides ratti also shows temperature-dependent changes in olfactory behavior, demonstrating that such changes occur in mammalian-parasitic nematodes. Conclusions IJs are developmentally arrested and long-lived, often surviving in the environment through multiple seasonal temperature changes. Temperature-dependent modulation of behavior may enable IJs to optimize host seeking in response to changing environmental conditions, and may play a previously unrecognized role in shaping the interactions of both beneficial and harmful parasitic nematodes with their hosts. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0259-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joon Ha Lee
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, 90095, USA
| | - Adler R Dillman
- Department of Nematology, University of California, Riverside, California, 92521, USA
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, 90095, USA.
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Hazir S, Shapiro-Ilan DI, Hazir C, Leite LG, Cakmak I, Olson D. Multifaceted effects of host plants on entomopathogenic nematodes. J Invertebr Pathol 2016; 135:53-9. [PMID: 26896698 DOI: 10.1016/j.jip.2016.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/08/2016] [Accepted: 02/15/2016] [Indexed: 11/21/2022]
Abstract
The success of parasites can be impacted by multi-trophic interactions. Tritrophic interactions have been observed in parasite-herbivore-host plant systems. Here we investigate aspects of multi-trophic interactions in a system involving an entomopathogenic nematode (EPN), its insect host, and host plant. Novel issues investigated include the impact of tritrophic interactions on nematode foraging behavior, the ability of EPNs to overcome negative tritrophic effects through genetic selection, and interactions with a fourth trophic level (nematode predators). We tested infectivity of the nematode, Steinernema riobrave, to corn earworm larvae (Helicoverpa zea) in three host plants, tobacco, eggplant and tomato. Tobacco reduced nematode virulence and reproduction relative to tomato and eggplant. However, successive selection (5 passages) overcame the deficiency; selected nematodes no longer exhibited reductions in phenotypic traits. Despite the loss in virulence and reproduction nematodes, first passage S. riobrave was more attracted to frass from insects fed tobacco than insects fed on other host plants. Therefore, we hypothesized the reduced virulence and reproduction in S. riobrave infecting tobacco fed insects would be based on a self-medicating tradeoff, such as deterring predation. We tested this hypothesis by assessing predatory success of the mite Sancassania polyphyllae and the springtail Sinella curviseta on nematodes reared on tobacco-fed larvae versus those fed on greater wax moth, Galleria mellonella, tomato fed larvae, or eggplant fed larvae. No advantage was observed in nematodes derived from tobacco fed larvae. In conclusion, our results indicated that insect-host plant diet has an important effect on nematode foraging, infectivity and reproduction. However, negative host plant effects, might be overcome through directed selection. We propose that host plant species should be considered when designing biocontrol programs using EPNs.
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Affiliation(s)
- Selcuk Hazir
- Adnan Menderes University, Faculty of Arts and Sciences, Department of Biology, 09100 Aydin, Turkey; Southeastern Fruit and Tree Nut Research Laboratory, USDA-ARS, Byron, GA 31008, USA.
| | - David I Shapiro-Ilan
- Southeastern Fruit and Tree Nut Research Laboratory, USDA-ARS, Byron, GA 31008, USA.
| | - Canan Hazir
- Adnan Menderes University, Aydin Health Services Vocational School, 09100 Aydin, Turkey; Southeastern Fruit and Tree Nut Research Laboratory, USDA-ARS, Byron, GA 31008, USA
| | - Luis G Leite
- Instituto Biologico, APTA, CP 70, Campinas, SP 13001-970, Brazil; Southeastern Fruit and Tree Nut Research Laboratory, USDA-ARS, Byron, GA 31008, USA
| | - Ibrahim Cakmak
- Adnan Menderes University, Faculty of Agriculture, Department of Plant Protection, 09100 Aydin, Turkey
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Lacey L, Grzywacz D, Shapiro-Ilan D, Frutos R, Brownbridge M, Goettel M. Insect pathogens as biological control agents: Back to the future. J Invertebr Pathol 2015. [DOI: 10.1016/j.jip.2015.07.009] [Citation(s) in RCA: 545] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Development and population dynamics of Steinernema yirgalemense (Rhabditida: Steinernematidae) and growth characteristics of its associated Xenorhabdus indica symbiont in liquid culture. J Helminthol 2015; 90:364-71. [PMID: 26156314 DOI: 10.1017/s0022149x15000450] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Entomopathogenic nematodes have become a valuable addition to the range of biological control agents available for insect control. An endemic nematode, Steinernema yirgalemense, has been found to be effective against a wide range of key insect pests. The next step would be the mass production this nematode for commercial application. This requires the establishment of monoxenic cultures of both the nematode and the symbiotic bacterium Xenorhabdus indica. First-stage juveniles of S. yirgalemense were obtained from eggs, while X. indica was isolated from nematode-infected wax moth larvae. The population density of the various life stages of S. yirgalemense during the developmental phase in liquid culture was determined. The recovery of infective juveniles (IJs) to the third-stage feeding juveniles, was 67 ± 10%, reaching a maximum population density of 75,000 IJs ml- 1 on day 13 after inoculation. Adult density increased after 8 days, with the maximum female density being 4600 ml- 1 on day 15, whereas the maximum male density was 4300 ml- 1 on day 12. Growth curves for X. indica showed that the exponential phase was reached 15 h after inoculation to the liquid medium. The stationary phase was reached after 42 h, with an average of 51 × 107 colony-forming units ml- 1. Virulence tests showed a significant difference in insect mortality between in vitro- and in vivo-produced nematodes. The success obtained with the production of S. yirgalemense in liquid culture can serve as the first step in the optimizing and upscaling of the commercial production of nematodes in fermenters.
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Lateral Dispersal and Foraging Behavior of Entomopathogenic Nematodes in the Absence and Presence of Mobile and Non-Mobile Hosts. PLoS One 2015; 10:e0129887. [PMID: 26079715 PMCID: PMC4469322 DOI: 10.1371/journal.pone.0129887] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/15/2015] [Indexed: 11/19/2022] Open
Abstract
Entomopathogenic nematodes have been classified into cruisers (active searchers) and ambushers (sit and wait foragers). However, little is known about their dispersal and foraging behavior at population level in soil. We studied lateral dispersal of the ambush foraging Steinernema carpocapsae (ALL strain) and cruise foraging Heterorhabditis bacteriophora (GPS11 strain) from infected host cadavers in microcosms (0.05 m2) containing Wooster silt-loam soil (Oxyaquic fragiudalf) and vegetation in the presence or absence of non-mobile and mobile hosts. Results showed that the presence of a non-mobile host (Galleria mellonella larva in a wire mesh cage) enhanced H. bacteriophora dispersal for up to 24 hr compared with no-host treatment, but had no impact on S. carpocapsae dispersal. In contrast, presence of a mobile host (G. mellonella larvae) increased dispersal of S. carpocapsae compared with no host treatment, but had no effect on H. bacteriophora dispersal. Also H. bacteriophora was better at infecting non-mobile than mobile hosts released into the microcosms and S. carpocapsae was better at infecting mobile than non-mobile hosts, thus affirming the established cruiser-ambusher theory. However, results also revealed that a large proportion of infective juveniles (IJs) of both species stayed near (≤ 3.8 cm) the source cadaver (88-96% S. carpocapsae; 67-79% H. bacteriophora), and the proportion of IJs reaching the farthest distance (11.4 cm) was significantly higher for S. carpocapsae (1.4%) than H. bacteriophora (0.4%) in the presence of mobile hosts. S. carpocapsae also had higher average population displacement than H. bacteriophora in the presence of both the non-mobile (5.07 vs. 3.6 cm/day) and mobile (8.06 vs. 5.3 cm/day) hosts. We conclude that the two species differ in their dispersal and foraging behavior at the population level and this behavior is affected by both the presence and absence of hosts and by their mobility.
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Bishop AM, Denton P, Pomeroy P, Twiss S. Good vibrations by the beach boys: magnitude of substrate vibrations is a reliable indicator of male grey seal size. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2014.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Demarta L, Hibbard BE, Bohn MO, Hiltpold I. The role of root architecture in foraging behavior of entomopathogenic nematodes. J Invertebr Pathol 2014; 122:32-9. [PMID: 25149039 DOI: 10.1016/j.jip.2014.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 08/05/2014] [Accepted: 08/11/2014] [Indexed: 01/02/2023]
Abstract
As obligate parasites, entomopathogenic nematodes (EPN) rely on insect hosts to complete their development. In insect pest management, EPN infectiousness has varied a lot. A better understanding of their host-finding behavior in the rhizosphere is therefore crucial to enhance EPN potential in biological control. As previously demonstrated, roots can be used as a pathway to insect hosts by EPN, but this interaction and its impact on EPN foraging remain poorly documented. Three artificial model-roots with different degrees of complexity and connectivity were designed to investigate the impact of root architecture on foraging behavior of the EPN Heterorhabditis megidis. Insect baits were placed at the bottom of each model-root that was subsequently buried in moist sand. After injection of the EPN, the number of EPN-infected baits as well as the number of mature nematodes inside each individual carcass was recorded. The influence of insect-induced root volatiles was also evaluated by spiking the baits with a synthetic version of a natural insect-induced root cue. The ecological relevance of the results was tested in soil with two maize genotypes each exhibiting broadly different root architectures. H. megidi performed better in presence of model-roots. Foraging performances of H. megidis declined with the increasing model-root complexity. Adding the synthetic root volatile dramatically changed this pattern and favored the EPN on the most complex model-roots. H. megidis also moved in the vicinity of maize roots to find the insect baits in soil, and natural root architecture also tended to shape H. megidis foraging behavior. This study adds to the scarce body of literature characterizing physical and chemical interactions between EPN and roots. The present data illustrate that root architecture not only modifies plant quality but also shapes upper trophic levels' ecology.
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Affiliation(s)
- Lanila Demarta
- Division of Plant Sciences, University of Missouri, 205 Curtis Hall, Columbia, MO 65211, USA
| | - Bruce E Hibbard
- USDA-ARS, Plant Genetic Research, University of Missouri, 205 Curtis Hall, Columbia, MO 65211, USA
| | - Martin O Bohn
- Maize Breeding and Genetics, Crop Science Department, University of Illinois, S-110 Turner Hall, 1102 S. Goodwin, Urbana, IL 61801, USA
| | - Ivan Hiltpold
- Division of Plant Sciences, University of Missouri, 205 Curtis Hall, Columbia, MO 65211, USA.
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Okumura E, Yoshiga T. Host orientation using volatiles in the phoretic nematode Caenorhabditis japonica. ACTA ACUST UNITED AC 2014; 217:3197-9. [PMID: 25063857 DOI: 10.1242/jeb.105353] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Host orientation is the most important step in host-searching nematodes; however, information on direct cues from hosts to evoke this behaviour is limited. Caenorhabditis japonica establishes a species-specific phoresy with Parastrachia japonensis. Dauer larvae (DL), the non-feeding and phoretic stage of C. japonica, are predominantly found on female phoretic hosts, but the mechanisms underlying the establishment of this phoresy remain unknown. To determine whether C. japonica DL are able to recognize and orient themselves to a host using a volatile cue from the host, we developed a Y-tube olfactory assay system in which C. japonica DL were significantly attracted to the air from P. japonensis but not to the air from three other insects or to CO2. These results demonstrated that C. japonica DL utilize volatiles for host recognition and orientation and that the presence of a specific volatile kairomone released by the host attracts C. japonica DL.
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Affiliation(s)
- Etsuko Okumura
- Laboratory of Nematology, Department of Applied Biological Sciences, Faculty of Agriculture, Saga University, Saga 840-8502, Japan The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-8580, Japan
| | - Toyoshi Yoshiga
- Laboratory of Nematology, Department of Applied Biological Sciences, Faculty of Agriculture, Saga University, Saga 840-8502, Japan
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Abstract
Sensory systems can adapt to different environmental signals. Here we identify four conditions that modulate anterior touch sensitivity in Caenorhabditis elegans after several hours and demonstrate that such sensory modulation is integrated at multiple levels to produce a single output. Prolonged vibration involving integrin signaling directly sensitizes the touch receptor neurons (TRNs). In contrast, hypoxia, the dauer state, and high salt reduce touch sensitivity by preventing the release of long-range neuroregulators, including two insulin-like proteins. Integration of these latter inputs occurs at upstream neurohormonal cells and at the insulin signaling cascade within the TRNs. These signals and those from integrin signaling converge to modulate touch sensitivity by regulating AKT kinases and DAF-16/FOXO. Thus, activation of either the integrin or insulin pathways can compensate for defects in the other pathway. This modulatory system integrates conflicting signals from different modalities, and adapts touch sensitivity to both mechanical and non-mechanical conditions.
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Sharifi S, Sharifi S, Karimi J, Sharifi S, Karimi J, Hosseini M, Sharifi S, Karimi J, Hosseini M, Rezapanah M. Efficacy of two entomopathogenic nematode species as potential biocontrol agents against the rosaceae longhorned beetle, Osphranteria coerulescens, under laboratory conditions. NEMATOLOGY 2014. [DOI: 10.1163/15685411-00002802] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rosaceae longhorned beetle, Osphranteria coerulescens, is an important pest of fruit trees that attacks all fruit trees belonging to the family Rosaceae in cold regions of Iran. The potential efficacy of two species of entomopathogenic nematodes (EPN), Heterorhabditis bacteriophora and Steinernema carpocapsae, against last instar larvae of this pest was tested under laboratory conditions. In plate assays, the larvae were susceptible to both EPN species but were more susceptible to S. carpocapsae (65.0-97.5% mortality) than H. bacteriophora (42.5-87.8%). Both nematode species were able to penetrate and reproduce within O. coerulescens larvae, but reproduction rate for H. bacteriophora was higher than those of S. carpocapsae; however, the penetration rate for S. carpocapsae was greater than H. bacteriophora. In a migration test on agar plate, S. carpocapsae showed negligible attraction to the pest or to Galleria mellonella cues. However, H. bacteriophora was strongly attracted to the sector of Petri dishes containing larvae. In a test using apricot tree branches, both species of EPN passed from mass frass of O. coerulescens larvae in the tip of the branches, penetrated into the larval galleries, and located and killed the larvae of O. coerulescens in their natural habitat deep inside the branches. Our findings provide the first insight into the biocontrol efficacy of EPN against O. coerulescens larvae, and highlight their potential for the control of this pest. Field experiments are needed to evaluate their potential under the environmental conditions in which rosaceae longhorned beetle larvae are found.
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Affiliation(s)
- Shervin Sharifi
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Shervin Sharifi
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Javad Karimi
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Shervin Sharifi
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Javad Karimi
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mojtaba Hosseini
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Shervin Sharifi
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Javad Karimi
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mojtaba Hosseini
- Biocontrol and Insect Pathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
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Shapiro-Ilan DI, Lewis EE, Schliekelman P. Aggregative group behavior in insect parasitic nematode dispersal. Int J Parasitol 2013; 44:49-54. [PMID: 24184157 DOI: 10.1016/j.ijpara.2013.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 10/01/2013] [Accepted: 10/05/2013] [Indexed: 01/18/2023]
Abstract
Movement behavior of foraging animals is critical to the determination of their spatial ecology and success in exploiting resources. Individuals sometimes gain advantages by foraging in groups to increase their efficiency in garnering these resources. Group movement behavior has been studied in various vertebrates. In this study we explored the propensity for innate group movement behavior among insect parasitic nematodes. Given that entomopathogenic nematodes benefit from group attack and infection, we hypothesised that the populations would tend to move in aggregate in the absence of extrinsic cues. Movement patterns of entomopathogenic nematodes in sand were investigated when nematodes were applied to a specific locus or when the nematodes emerged naturally from infected insect hosts; six nematode species in two genera were tested (Heterorhabditis bacteriophora, Heterorhabditis indica, Steinernema carpocapsae, Steinernema feltiae, Steinernema glaseri and Steinernema riobrave). Nematodes were applied in aqueous suspension via filter paper discs or in infected insect host cadavers (to mimic emergence in nature). We discovered that nematode dispersal resulted in an aggregated pattern rather than a random or uniform distribution; the only exception was S. glaseri when emerging directly from infected hosts. The group movement may have been continuous from the point of origin, or it may have been triggered by a propensity to aggregate after a short period of random movement. To our knowledge, this is the first report of group movement behavior in parasitic nematodes in the absence of external stimuli (e.g., without an insect or other apparent biotic or abiotic cue). These findings have implications for nematode spatial distribution and suggest that group behavior is involved in nematode foraging.
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Affiliation(s)
| | - Edwin E Lewis
- University of California Davis, Department of Nematology and Entomology, University of California, Davis, CA 95616, USA
| | - Paul Schliekelman
- Department of Statistics, University of Georgia, Athens, GA 30602, USA.
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Campos-Herrera R, Ali JG, Diaz BM, Duncan LW. Analyzing spatial patterns linked to the ecology of herbivores and their natural enemies in the soil. FRONTIERS IN PLANT SCIENCE 2013; 4:378. [PMID: 24137165 PMCID: PMC3786222 DOI: 10.3389/fpls.2013.00378] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 09/03/2013] [Indexed: 05/11/2023]
Abstract
Modern agricultural systems can benefit from the application of concepts and models from applied ecology. When understood, multitrophic interactions among plants, pests, diseases and their natural enemies can be exploited to increase crop production and reduce undesirable environmental impacts. Although the understanding of subterranean ecology is rudimentary compared to the perspective aboveground, technologies today vastly reduce traditional obstacles to studying cryptic communities. Here we emphasize advantages to integrating as much as possible the use of these methods in order to leverage the information gained from studying communities of soil organisms. PCR-based approaches to identify and quantify species (real time qPCR and next generation sequencing) greatly expand the ability to investigate food web interactions because there is less need for wide taxonomic expertise within research programs. Improved methods to capture and measure volatiles in the soil atmosphere in situ make it possible to detect and study chemical cues that are critical to communication across trophic levels. The application of SADIE to directly assess rather than infer spatial patterns in belowground agroecosystems has improved the ability to characterize relationships between organisms in space and time. We review selected methodology and use of these tools and describe some of the ways they were integrated to study soil food webs in Florida citrus orchards with the goal of developing new biocontrol approaches.
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Affiliation(s)
- R. Campos-Herrera
- Departamento de Contaminación Ambiental, Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones CientíficasMadrid, Spain
- Entomology and Nematology Department, Citrus Research and Education Center, University of FloridaLake Alfred, FL, USA
| | - J. G. Ali
- Entomology and Nematology Department, Citrus Research and Education Center, University of FloridaLake Alfred, FL, USA
- Department of Ecology and Evolutionary Biology, Cornell UniversityIthaca, NY, USA
| | - B. M. Diaz
- Departamento de Protección Vegetal, Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - L. W. Duncan
- Entomology and Nematology Department, Citrus Research and Education Center, University of FloridaLake Alfred, FL, USA
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Wang Y, Lutfi Z, Dong L, Suman DS, Sanad M, Gaugler R. Host cues induce egg hatching and pre-parasitic foraging behaviour in the mosquito parasitic nematode, Strelkovimermis spiculatus. Int J Parasitol 2012; 42:881-6. [PMID: 22935096 DOI: 10.1016/j.ijpara.2012.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 06/27/2012] [Accepted: 06/28/2012] [Indexed: 10/28/2022]
Abstract
The responses of eggs in diapause and the infective stage of the nematode, Strelkovimermis spiculatus, to larvae of its host, Culex pipiens pipiens, were investigated in the laboratory. The results indicated that the presence of the host induced the egg hatching. The hatching rate increased when larger numbers of host larvae were present. Second instar mosquito larvae induced significantly higher hatching rates than any other stages. These findings explain how S. spiculatus synchronizes its life cycle with its host life cycle and population dynamics to increase its fitness when the natural habitat is constantly covered by water. Direct exposure of the nematode eggs to host larvae resulted in consumption of as many as 20 eggs per host. The eggs consumed caused 0-70% host mortality depending on the number consumed, which indicated an infection path other than cuticle penetration although it may represent a rare situation in nature. The result of host cue assays showed that the combination of chemical cues and physical vibration induced the highest egg hatching, which may increase the chance of host availability after hatching. However, once hatched, the nematodes ignored vibrations and used only chemical cues for host location. These findings suggest that eggs hatch synchronously with the most susceptible mosquito stage and with peak mosquito larval density.
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Affiliation(s)
- Yi Wang
- Center for Vector Biology, Rutgers University, New Brunswick, NJ 08901-8536, USA.
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Olfaction shapes host-parasite interactions in parasitic nematodes. Proc Natl Acad Sci U S A 2012; 109:E2324-33. [PMID: 22851767 DOI: 10.1073/pnas.1211436109] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many parasitic nematodes actively seek out hosts in which to complete their lifecycles. Olfaction is thought to play an important role in the host-seeking process, with parasites following a chemical trail toward host-associated odors. However, little is known about the olfactory cues that attract parasitic nematodes to hosts or the behavioral responses these cues elicit. Moreover, what little is known focuses on easily obtainable laboratory hosts rather than on natural or other ecologically relevant hosts. Here we investigate the olfactory responses of six diverse species of entomopathogenic nematodes (EPNs) to seven ecologically relevant potential invertebrate hosts, including one known natural host and other potential hosts collected from the environment. We show that EPNs respond differentially to the odor blends emitted by live potential hosts as well as to individual host-derived odorants. In addition, we show that EPNs use the universal host cue CO(2) as well as host-specific odorants for host location, but the relative importance of CO(2) versus host-specific odorants varies for different parasite-host combinations and for different host-seeking behaviors. We also identified host-derived odorants by gas chromatography-mass spectrometry and found that many of these odorants stimulate host-seeking behaviors in a species-specific manner. Taken together, our results demonstrate that parasitic nematodes have evolved specialized olfactory systems that likely contribute to appropriate host selection.
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Campos-Herrera R, El-Borai FE, Duncan LW. Real-time PCR as an effective technique to assess the impact of phoresy by Paenibacillus sp. bacteria on Steinernema diaprepesi nematodes in nature. Mol Ecol Resour 2012; 12:885-93. [PMID: 22672645 DOI: 10.1111/j.1755-0998.2012.03159.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Quantitative real-time PCR (qPCR) is a powerful tool to study species of cryptic organisms in complex food webs. This technique was recently developed to detect and quantify several species of entomopathogenic nematodes (EPNs), which are widely used for biological control of insects, and some natural enemies of EPNs such as nematophagous fungi and the phoretic bacteria Paenibacillus sp. and Paenibacillus nematophilus. A drawback to the use of primers and TaqMan probes designed for Paenibacillus sp. is that the qPCR also amplified Paenibacillus thiaminolyticus and Paenibacillus popilliae, two closely related species that are not phoretically associated with EPNs. Here, we report that the detection of Paenibacillus sp. DNA in nematode samples was two orders of magnitude greater (P < 0.001) when the bacterium was added to soil together with its EPN species-specific host Steinernema diaprepesi than when it was added concomitantly with other EPNs or with species of bacterial-feeding nematodes. Just 6% of samples detected trace amounts of P. thiaminolyticus and P. popilliae exposed to the same experimental conditions. Thus, although the molecular assay detects Paenibacillus spp. DNA in nonphoretic associations, the levels are essentially background compared to the detection of Paenibacillus sp. in association with its nematode host.
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Affiliation(s)
- R Campos-Herrera
- Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, IFAS, 700 Experiment Station Road, Lake Alfred, FL 33850-2299, USA.
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Gulcu B, Hazir S, Kaya HK. Scavenger deterrent factor (SDF) from symbiotic bacteria of entomopathogenic nematodes. J Invertebr Pathol 2012; 110:326-33. [PMID: 22446508 DOI: 10.1016/j.jip.2012.03.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 03/06/2012] [Accepted: 03/13/2012] [Indexed: 11/17/2022]
Abstract
Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis are symbiotically associated with bacteria in the genera Xenorhabdus and Photorhabdus, respectively. The symbiotic bacteria produce a chemical compound(s) that deterred ants from feeding on nematode-killed insects (i.e., cadavers) and has been previously referred to as an Ant Deterrent Factor (ADF). We studied the response of different arthropod scavenger species which included the ant Lepisiota frauenfeldi, cricket Gryllus bimaculatus, wasps Vespa orientalis and Paravespula sp., and calliphorid fly Chrysomya albiceps, to ADF. These scavengers (ants, crickets, and wasps) were exposed to cadavers with and without the nematode/bacterium complex or to Photorhabdus luminescens cultures of different ages on different substrates. The ant, cricket, and wasp species did not feed on nematode-killed insects containing the nematode/bacterium complex that were 2 days old and older but fed on 1-day-old nematode-killed and freeze -killed insects. Crickets consumed 2- to 7-day-old axenic nematode-killed insects, 1-, 4-, and 5-day-old insects killed by the bacterium, Serratia marcescens, and freeze-killed, putrid insects that were up to 10 days old. The crickets only partially consumed 2- and 3-day-old insects killed by S. marcescens which differed significantly from the 1-, 4-, and 5-day-old killed insects by this bacterium. Ants fed only on 5% sucrose solution (control) and 1- to 3- day old cultures of P. luminescens containing 5% sucrose but not on older cultures of P. luminescens. Wasps did not feed on meat treated with P. luminescens supernatant, whereas they fed on meat treated with Escherichia coli supernatant and control meat. Calliphorid flies did not oviposit on meat treated with P. luminescens supernatant but did oviposit on untreated meat. Based on the response of these scavengers, the chemical compound(s) responsible for this deterrent activity should be called "scavenger deterrent factor" (SDF).
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Affiliation(s)
- Baris Gulcu
- Duzce University, Faculty of Arts and Science, Department of Biology, 81620 Duzce, Turkey
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Shapiro-Ilan DI, Lewis EE, Campbell JF, Kim-Shapiro DB. Directional movement of entomopathogenic nematodes in response to electrical field: effects of species, magnitude of voltage, and infective juvenile age. J Invertebr Pathol 2012; 109:34-40. [DOI: 10.1016/j.jip.2011.09.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 09/02/2011] [Accepted: 09/06/2011] [Indexed: 10/17/2022]
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Hiltpold I, Erb M, Robert CAM, Turlings TCJ. Systemic root signalling in a belowground, volatile-mediated tritrophic interaction. PLANT, CELL & ENVIRONMENT 2011; 34:1267-75. [PMID: 21477121 DOI: 10.1111/j.1365-3040.2011.02327.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Plants attacked by leaf herbivores release volatile organic compounds (VOCs) both locally from the wounded site and systemically from non-attacked tissues. These volatiles serve as attractants for predators and parasitoids. This phenomenon is well described for plant leaves, but systemic induction of VOCs in the roots has remained unstudied. We assessed the spatial and temporal activation of the synthesis and release of (E)-β-caryophyllene (EβC) in maize roots upon feeding by larvae of Diabrotica virgifera virgifera, as well as the importance of systemically produced EβC for the attraction of the entomopathogenic nematode Heterorhabditis megidis. The production of EβC was found to be significantly stronger at the site of attack than in non-attacked tissues. A weak, but significant, increase in transcriptional activity of the EβC synthase gene tps23 and a corresponding increase in EβC content were observed in the roots above the feeding site and in adjacent roots, demonstrating for the first time that herbivory triggers systemic production of a volatile within root systems. In belowground olfactometers, the nematodes were significantly more attracted towards local feeding sites than systemically induced roots. The possible advantages and disadvantages of systemic volatile signalling in roots are discussed.
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Affiliation(s)
- Ivan Hiltpold
- FARCE Laboratory, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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37
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Ali JG, Alborn HT, Stelinski LL. Constitutive and induced subterranean plant volatiles attract both entomopathogenic and plant parasitic nematodes. JOURNAL OF ECOLOGY 2011; 99:26-35. [PMID: 0 DOI: 10.1111/j.1365-2745.2010.01758.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Ennis DE, Dillon AB, Griffin CT. Simulated roots and host feeding enhance infection of subterranean insects by the entomopathogenic nematode Steinernema carpocapsae. J Invertebr Pathol 2009; 103:140-3. [PMID: 19932700 DOI: 10.1016/j.jip.2009.11.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 10/20/2009] [Accepted: 11/17/2009] [Indexed: 10/20/2022]
Abstract
Steinernema carpocapsae can be effective against root-feeding insects despite its reputation as a sedentary ambusher. In pot experiments, using twigs as surrogate roots and pine weevil larvae as targets, we tested the hypothesis that roots serve as physical routeways and conduits of feeding-associated stimuli, thus enhancing the success of S. carpocapsae applied at the surface against subterranean hosts. Insect mortality was lowest (25%) in the absence of plant material, increased to 48% when twigs linked nematodes and insects, and further increased to 69% when the insects were allowed feed on the twigs. This is the first experimental support for the root-routeway hypothesis.
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Affiliation(s)
- D E Ennis
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland.
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The influence of habitat quality on the foraging strategies of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis megidis. Parasitology 2009; 137:303-9. [DOI: 10.1017/s0031182009991326] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYEntomopathogenic nematodes (EPN) are soil-transmitted parasites and their foraging strategies are believed to range from ‘ambush’ to ‘cruise’ foragers. However, research on their behaviour has not considered the natural habitat of these nematodes. We hypothesized that EPN behaviour would be influenced by soil habitat quality and tested this hypothesis using 2 EPN species Steinernema carpocapsae (an ‘ambusher’) and Heterorhabditis megidis (a ‘cruiser’) in 2 contrasting habitats, sand and peat. As predicted from previous studies, in sand most S. carpocapsae remained at the point of application and showed no taxis towards hosts, but in peat S. carpocapsae dispersed much more and showed a highly significant taxis towards hosts. H. megidis dispersed well in both media, but only showed taxis towards hosts in sand. In outdoor mesocosms in which both species were applied, S. carpocapsae outcompeted H. megidis in terms of host finding in peat, whereas the opposite was true in sand. Our data suggest that these 2 EPN may be habitat specialists and highlight the difficulties of studying soil-transmitted parasites in non-soil media.
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Hill PSM. How do animals use substrate-borne vibrations as an information source? Naturwissenschaften 2009; 96:1355-71. [PMID: 19593539 DOI: 10.1007/s00114-009-0588-8] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 06/15/2009] [Accepted: 06/30/2009] [Indexed: 11/26/2022]
Abstract
Animal communication is a dynamic field that promotes cross-disciplinary study of the complex mechanisms of sending and receiving signals, the neurobiology of signal detection and processing, and the behaviors of animals creating and responding to encoded messages. Alongside visual signals, songs, or pheromones exists another major communication channel that has been rather neglected until recent decades: substrate-borne vibration. Vibrations carried in the substrate are considered to provide a very old and apparently ubiquitous communication channel that is used alone or in combination with other information channels in multimodal signaling. The substrate could be 'the ground', or a plant leaf or stem, or the surface of water, or a spider's web, or a honeybee's honeycomb. Animals moving on these substrates typically create incidental vibrations that can alert others to their presence. They also may use behaviors to create vibrational waves that are employed in the contexts of mate location and identification, courtship and mating, maternal care and sibling interactions, predation, predator avoidance, foraging, and general recruitment of family members to work. In fact, animals use substrate-borne vibrations to signal in the same contexts that they use vision, hearing, touch, taste, or smell. Study of vibrational communication across animal taxa provides more than just a more complete story. Communication through substrate-borne vibration has its own constraints and opportunities not found in other signaling modalities. Here, I review the state of our understanding of information acquisition via substrate-borne vibrations with special attention to the most recent literature.
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Directional movement of steinernematid nematodes in response to electrical current. J Invertebr Pathol 2009; 100:134-7. [DOI: 10.1016/j.jip.2008.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 10/31/2008] [Accepted: 11/04/2008] [Indexed: 11/23/2022]
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Rae R, Verdun C, Grewal PS, Robertson JF, Wilson MJ. Biological control of terrestrial molluscs using Phasmarhabditis hermaphrodita--progress and prospects. PEST MANAGEMENT SCIENCE 2007; 63:1153-64. [PMID: 17912686 DOI: 10.1002/ps.1424] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Phasmarhabditis hermaphrodita Schneider (Nematoda: Rhabditidae) is a nematode that parasitises a wide range of slug and snail species. It has been formulated into a biological control agent (Nemaslug) and was commercialised in 1994. It is now available in fourteen European countries. A review is given of all research on P. hermaphrodita, including basic biology, mass cultivation, formulation, host range, application strategies, field efficacy and effects on non-target organisms. The many critical gaps in present knowledge are highlighted, and future research is proposed that will lead to greater understanding of this unusual parasite and may enable its more widespread use in the management of mollusc pests.
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Affiliation(s)
- Robbie Rae
- Max Planck Institute for Developmental Biology, Department of Evolutionary Biology, Spemannstrasse 35, Tuebingen, Germany.
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