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Kour S, Khurma U, Brodie G. Ecological Characterisation of Native Isolates of Heterorhabditis indica from Viti Levu, Fiji Islands. J Nematol 2021; 53:e2021-85. [PMID: 34723189 PMCID: PMC8552510 DOI: 10.21307/jofnem-2021-085] [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: 04/12/2021] [Indexed: 11/11/2022] Open
Abstract
Entomopathogenic nematodes (EPNs) in the families Steinernematidae and Heterorhabditidae are obligate parasites of soil inhibiting insects. EPNs are being widely researched as promising biocontrol agents for a wide range of agricultural pests. It is known that strains of EPNs isolated from different geographical regions differ in their attributes, such as host-finding ability, host range, infectivity, reproduction, and environmental stress tolerance. A precise knowledge of these factors is therefore an essential pre-requisite for devising successful strategies to use these nematodes in biological control programmes. Thus, ecological characterisation of the EPN Heterorhabditis indica (Rhabditida: Heterorhabditidae) newly isolated and representing the only species of EPN reported from the island of Viti Levu, Fiji was carried out using Galleria mellonella larvae (L) (Pyralidae: Galleriinae) as hosts to allow comparisons between bioassays conducted in different laboratories around the world. Temperature data showed that native isolates of H. indica are warm-adapted nematodes with thermal range for infectivity between 15˚C and 35˚C and can reproduce between 20˚C and 30˚C. They are highly virulent with LC50 values against G. mellonella ranging from 2.8 IJ to 3.8 IJ/larva. However, they showed poor desiccation tolerance and fail to infect hosts in soil with moisture levels below 8%. They showed a moderate level of hypoxic tolerance and can be stored at 15˚C for 4 months. Results also showed great variability within the selected native isolates of H. indica. Beneficial traits for selected isolates were added up to identify a superior candidate. The current study also suggested that the thermal niche breadth for infection can differ among conspecific strains of an EPN species. The results of this experimental study on ecological aspects of these native isolates of H. indica should form a basis for their potential use in biological control of insect pests in Fiji.
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Affiliation(s)
- Sumeet Kour
- School of Agricultural, Geography, Environment Ocean and Natural Science, The University of the South Pacific, Fiji Islands
| | - Uma Khurma
- School of Agricultural, Geography, Environment Ocean and Natural Science, The University of the South Pacific, Fiji Islands
| | - Gilianne Brodie
- Institute of Applied Sciences, The University of the South Pacific, Fiji Islands
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Yan X, Chen G, Chen Y, Sun B, Gu X, Ruan W, Han R. Virulence of Steinernema ceratophorum against different pest insects and their potential for in vivo and in vitro culture. J Nematol 2021. [DOI: 10.21307/jofnem-2021-046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Ma J, Gao B, Wang R, Li X, Chen S. Transcriptome analyses of Ditylenchus destructor in responses to cold and desiccation stress. Genet Mol Biol 2020; 43:e20180057. [PMID: 32232317 PMCID: PMC7198036 DOI: 10.1590/1678-4685-gmb-2018-0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/03/2019] [Indexed: 11/22/2022] Open
Abstract
The objective of this study was to identify molecular responses in Ditylenchus destructor to cold and desiccation by means of transcriptomes analyses. A total of 102,517 unigenes were obtained, with an average length of 1,076 bp, in which 58,453 (57%) had a functional annotation. A total of 1154 simple sequence repeats (SSRs) distributed over 1078 unigenes were detected. Gene expression profiles in response to cold and desiccation stress and the expression of specific stress-related genes were compared. Gene ontology analysis and pathway-based analysis were used to further investigate the functions of the differentially expressed genes. The reliability of the sequencing data was verified through quantitative real-time PCR analysis of 19 stress-related genes. RNA interference used to further assess the functions of the cold-related unigenes 15628 and 15596 showed that the knockdown of each of these genes led to decreased cold tolerance of D. destructor. Hence, this study revealed molecular processes and pathways active in cold- or dessication-treated nematodes. The transcriptome profiles presented in this study provide insight into the transcriptome complexity and will contribute to further understand stress tolerance in D. destructor.
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Affiliation(s)
- Juan Ma
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Bo Gao
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Rongyan Wang
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Xiuhua Li
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Shulong Chen
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
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Chen C, Ma H, Ma M, Li J, Zheng S, Song Q, Gu X, Shapiro-Ilan D, Ruan W. An innovative strategy for control of fungus gnats using entomopathogenic nematodes alone or in combination with waterlogging. J Nematol 2020; 52:1-9. [PMID: 32628823 PMCID: PMC7366836 DOI: 10.21307/jofnem-2020-057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Indexed: 11/12/2022] Open
Abstract
Chive gnat (Bradysia odoriphaga) is a soil-borne pest of Chinese chives, which causes millions of dollars in yield losses per year. Traditional methods, such as chemical pesticides leave detrimental chemical residues on plants, which potentially threaten human health. To find a sustainable method of reducing the chive gnat, the authors evaluated the effects of waterlogging and the addition of entomopathogenic nematode (EPN) on reducing chive gnat in Chinese chives via three pot experiments and one field demonstration. Results indicated that increasing the duration of waterlogging markedly increases chive gnat mortality. The presence of EPN also caused chive gnat mortality to increase with exposure time. Most importantly, the combination of waterlogging and EPN had synergistic effects on chive gnat mortality; the combination led to higher mortality than using waterlogging and EPN alone. The study demonstrated that a combination of two environmental friendly methods of fungus gnat control could lead to synergistic effects, which may provide novel approaches to economic and environmentally sustainable pest management measures. Chive gnat (Bradysia odoriphaga) is a soil-borne pest of Chinese chives, which causes millions of dollars in yield losses per year. Traditional methods, such as chemical pesticides leave detrimental chemical residues on plants, which potentially threaten human health. To find a sustainable method of reducing the chive gnat, the authors evaluated the effects of waterlogging and the addition of entomopathogenic nematode (EPN) on reducing chive gnat in Chinese chives via three pot experiments and one field demonstration. Results indicated that increasing the duration of waterlogging markedly increases chive gnat mortality. The presence of EPN also caused chive gnat mortality to increase with exposure time. Most importantly, the combination of waterlogging and EPN had synergistic effects on chive gnat mortality; the combination led to higher mortality than using waterlogging and EPN alone. The study demonstrated that a combination of two environmental friendly methods of fungus gnat control could lead to synergistic effects, which may provide novel approaches to economic and environmentally sustainable pest management measures.
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Affiliation(s)
- Chaoying Chen
- College of Life Sciences, Nankai University, Tianjin 30071, China
| | - Haikun Ma
- College of Life Sciences, Nankai University, Tianjin 30071, China
| | - Mingyang Ma
- College of Life Sciences, Nankai University, Tianjin 30071, China
| | - Jingjing Li
- College of Life Sciences, Nankai University, Tianjin 30071, China
| | - Shuyuan Zheng
- College of Life Sciences, Nankai University, Tianjin 30071, China
| | - Qifeng Song
- College of Life Sciences, Nankai University, Tianjin 30071, China
| | - Xinghui Gu
- Yuxi Tobacco Company, Yunnan, 653100, China
| | | | - Weibin Ruan
- College of Life Sciences, Nankai University, Tianjin 30071, China
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Zhang X, Machado RA, Doan CV, Arce CC, Hu L, Robert CA. Entomopathogenic nematodes increase predation success by inducing cadaver volatiles that attract healthy herbivores. eLife 2019; 8:46668. [PMID: 31509107 PMCID: PMC6739876 DOI: 10.7554/elife.46668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 08/24/2019] [Indexed: 12/28/2022] Open
Abstract
Herbivore natural enemies protect plants by regulating herbivore populations. Whether they can alter the behavior of their prey to increase predation success is unknown. We investigate if and how infection by the entomopathogenic nematode Heterorhabditis bacteriophora changes the behavior of healthy larvae of the western corn rootworm (Diabrotica virgifera), a major pest of maize. We found that nematode-infected rootworm cadavers are attractive to rootworm larvae, and that this behavior increases nematode reproductive success. Nematode-infected rootworms release distinct volatile bouquets, including the unusual volatile butylated hydroxytoluene (BHT). BHT alone attracts rootworms, and increases nematode reproductive success. A screen of different nematode and herbivore species shows that attraction of healthy hosts to nematode-infected cadavers is widespread and likely involves species-specific volatile cues. This study reveals a new facet of the biology of herbivore natural enemies that boosts their predation success by increasing the probability of host encounters.
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Affiliation(s)
- Xi Zhang
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | | | - Cong Van Doan
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Carla Cm Arce
- Institute of Biology, University of Neuchatel, Neuchatel, Switzerland
| | - Lingfei Hu
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
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Yan X, Lin Y, Huang Z, Han R. Characterisation of biological and biocontrol traits of entomopathogenic nematodes promising for control of striped flea beetle (Phyllotreta striolata). NEMATOLOGY 2018. [DOI: 10.1163/15685411-00003155] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Summary
The biological and biocontrol traits of two entomopathogenic nematode isolates, Steinernema pakistanense 94-1 (Sp94-1) and Heterorhabditis indica 212-2 (Hi212-2), were evaluated. The highest yield of infective juveniles (IJ) in monoxenic sponge culture system for Sp94-1 and Hi212-2 was 3.52 (± 0.45) × 105 and 7.08 (± 0.11) × 105 IJ g−1, respectively. The optimum storage temperature was 25°C for Sp94-1 and 14°C for Hi212-2. Sp94-1 showed greater tolerance to heat exposure and UV radiation, while S. carpocapsae All, a commercial strain, was more resistant to osmotic pressure, desiccation, cold treatment and hypoxia than the other tested isolates. Hi212-2 suppressed the Phyllotreta striolata larvae when applied at 1.5 × 109 IJ ha−1 or higher concentrations, while Sp94-1 suppressed the P. striolata larvae only when applied at 4.5 × 109 IJ ha−1. Our study indicates the possibility of commercialisation of the EPN isolates, and further confirms their efficacy against the P. striolata larvae in the field.
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Affiliation(s)
- Xun Yan
- 1Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, No. 105 Xingang Road West, Guangzhou, P.R. China
| | - Yinying Lin
- 1Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, No. 105 Xingang Road West, Guangzhou, P.R. China
| | - Zhenmao Huang
- 2Foshan Xiaonong Eco-Technology Co., Ltd, Nanfeng Road, Leping county, Sanshui District, Foshan, P.R. China
| | - Richou Han
- 1Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, No. 105 Xingang Road West, Guangzhou, P.R. China
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Bai GY, Xu H, Fu YQ, Wang XY, Shen GS, Ma HK, Feng X, Pan J, Gu XS, Guo YZ, Ruan WB, Shapiro-Ilan DI. A Comparison of Novel Entomopathogenic Nematode Application Methods for Control of the Chive Gnat, Bradysia odoriphaga (Diptera: Sciaridae). JOURNAL OF ECONOMIC ENTOMOLOGY 2016; 109:2006-2013. [PMID: 27480971 DOI: 10.1093/jee/tow162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/25/2016] [Indexed: 06/06/2023]
Abstract
Bradysia odoriphaga Yang & Zhang (Diptera: Sciaridae) is the most serious pest of Chinese chive, Allium tuberosum Chemical pesticide application has become a necessary step to control B. odoriphaga after each of the four to six harvests during the growing season. We compared the effects of application type (nematode-infected cadaver, aqueous nematode suspension, and mixture of cadaver and aqueous suspension) and nematode species (Heterorhabditis bacteriophora vs. Steinernema carpocapsae) on B. odoriphaga control. Nematode species combinations and the use of the cadaver method has only been tested in a relatively few studies, and has not been tested for this target pest, B. odoriphaga. Furthermore, this is the first report of combining application methods (aqueous and cadaver). Results indicated that the cadaver treatment produced higher mortality of B. odoriphaga than the aqueous treatment, and H. bacteriophora caused higher mortality of B. odoriphaga than S. carpocapsae. The mortality of B. odoriphaga was 96.7% in H. bacteriophora cadaver treatment and only 27.5% in control treatment without nematode addition. Cadaver treatments caused higher biomass of A. tuberosum than that of aqueous treatment. The plant biomass in H. bacteriophora cadaver treatment was 10 folds as much as that in the control treatment. The mixed aqueous suspension of H. bacteriophora and S. carpocapsae did not increase the mortality in pot trial. Our findings indicate that entomopathogenic nematodes applied as cadavers might be a potential alternative biological agent in the integrated management of B. odoriphaga for Chinese chive production.
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Affiliation(s)
- Guang-Ying Bai
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
| | - Hua Xu
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
| | - Ya-Qi Fu
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
| | - Xiao-Ying Wang
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
| | - Guang-Shuang Shen
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
| | - Hai-Kun Ma
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
| | - Xiaoling Feng
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
| | - Jie Pan
- Tianjin Institute of Agricultural Resources and Environmental Sciences, Tianjin 300192, PR China
| | - Xi-Shu Gu
- Tianjin Institute of Plant Protection, Tianjin 300192, PR China
| | - Yong-Ze Guo
- Institution of Agricultural Quality Standards and Testing Technology, Tianjin 300381, PR China
| | - Wei-Bin Ruan
- College of Life Sciences, Nankai University, Tianjin 300071, PR China (; ; ; ; ; ; ; )
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