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Achhami BB, Reddy GVP, Hofland ML, Sherman JD, Peterson RKD, Weaver DK. Plant Volatiles and Oviposition Behavior in the Selection of Barley Cultivars by Wheat Stem Sawfly (Hymenoptera: Cephidae). ENVIRONMENTAL ENTOMOLOGY 2021; 50:940-947. [PMID: 33885745 DOI: 10.1093/ee/nvab035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Indexed: 06/12/2023]
Abstract
Wheat stem sawfly, [Cephus cinctus (Hymenoptera: Cephidae)], females display complex behaviors for host selection and oviposition. Susceptible hollow stem wheat (Triticum aestivum L.) cultivars release a greater amount of attractive compound, (Z)-3-hexenyl acetate and receive a greater number of eggs compared to resistant solid stem wheat cultivars. However, barley (Hordeum vulgare L.) is becoming a more common host for C. cinctus in Montana. Therefore, how do host selection and oviposition behaviors on barley cultivars compare to what happens when encountering wheat cultivars? To answer this question, we carried out greenhouse experiments using two barley cultivars: 'Hockett' and 'Craft'. Between these cultivars at Zadoks stages 34 and 49, we compared host selection decisions using a Y-tube olfactometer, compared oviposition behaviors on stems, and counted the number of eggs inside individual stems. In Y-tube bioassays, we found a greater number of C. cinctus females were attracted to the airstream passing over 'Hockett' than 'Craft' barley cultivars. Although the frequencies of oviposition behaviors were similar between these cultivars, the number of eggs was greater in 'Hockett'. Volatile profiles indicated that the amount of linalool was greater in the airstream from 'Craft' than in 'Hockett' at Zadoks 34 while the amount of (Z)-3-hexenyl acetate was greater in airstream from 'Hockett' at both Zadoks 34 and 49. These results suggest that volatiles of barley plants influenced host selection behavior of ovipositing C. cinctus females, while other discriminating behaviors do not differ between cultivars.
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Affiliation(s)
- Buddhi B Achhami
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Gadi V P Reddy
- USDA-ARS Southern Insect Management Research Unit, 141 Experiment Station Rd., P.O. Box 346, Stoneville, MS 38776, USA
| | - M L Hofland
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Jamie D Sherman
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717, USA
| | - Robert K D Peterson
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
| | - David K Weaver
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
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Achhami BB, Reddy GVP, Sherman JD, Peterson RKD, Weaver DK. Antixenosis, Antibiosis, and Potential Yield Compensatory Response in Barley Cultivars Exposed to Wheat Stem Sawfly (Hymenoptera: Cephidae) Under Field Conditions. JOURNAL OF INSECT SCIENCE (ONLINE) 2020; 20:9. [PMID: 32960968 PMCID: PMC7508298 DOI: 10.1093/jisesa/ieaa091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Indexed: 06/11/2023]
Abstract
Wheat stem sawfly, Cephus cinctus Norton, is an economically serious pest of cereals grown in North America. Barley cultivars were previously planted as resistant crops in rotations to manage C. cinctus, but due to increasing levels of injury to this crop, this is no longer a valid management tactic in Montana. Therefore, we aimed to understand antixenosis (behavioral preference), antibiosis (mortality), and potential yield compensation (increased productivity in response to stem injuries) in barley exposed to C. cinctus. We examined these traits in eight barley cultivars. Antixenosis was assessed by counting number of eggs per stem and antibiosis was assessed by counting infested stems, dead larvae, and stems cut by mature larvae. Potential yield compensation was evaluated by comparing grain yield from three categories of stem infestation: 1) uninfested, 2) infested with dead larva, and 3) infested cut by mature larva at crop maturity. We found the greatest number of eggs per infested stem (1.80 ± 0.04), the highest proportion of infested stems (0.63 ± 0.01), and the highest proportion of cut stems (0.33 ± 0.01) in 'Hockett'. Seven out of eight cultivars had greater grain weight for infested stems than for uninfested stems. These cultivars may have compensatory responses to larval feeding injury. Overall, these barley cultivars contain varying levels of antixenosis, antibiosis, and differing levels of yield compensation. Our results provide foundational knowledge on barley traits that will provide a framework to further develop C. cinctus resistant or tolerant barley cultivars.
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Affiliation(s)
- Buddhi B Achhami
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT
| | - Gadi V P Reddy
- Western Triangle Agricultural Research Center, Conrad, MT
- USDA ARS-Southern Insect Management Research Unit, Stoneville, MS
| | - Jamie D Sherman
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT
| | - Robert K D Peterson
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT
| | - David K Weaver
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT
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Yeoman CJ, Brutscher LM, Esen ÖC, Ibaoglu F, Fowler C, Eren AM, Wanner K, Weaver DK. Genome-resolved insights into a novel Spiroplasma symbiont of the Wheat Stem Sawfly ( Cephus cinctus). PeerJ 2019; 7:e7548. [PMID: 31523509 PMCID: PMC6716498 DOI: 10.7717/peerj.7548] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 07/25/2019] [Indexed: 12/24/2022] Open
Abstract
Arthropods often have obligate relationships with symbiotic microbes, and recent investigations have demonstrated that such host-microbe relationships could be exploited to suppress natural populations of vector carrying mosquitos. Strategies that target the interplay between agricultural pests and their symbionts could decrease the burden caused by agricultural pests; however, the lack of comprehensive genomic insights into naturally occurring microbial symbionts presents a significant bottleneck. Here we employed amplicon surveys, genome-resolved metagenomics, and scanning electron microscopy to investigate symbionts of the wheat stem sawfly (Cephus cinctus), a major pest that causes an estimated $350 million dollars or more in wheat yield losses in the northwestern United States annually. Through 16S rRNA gene sequencing of two major haplotypes and life stages of wheat stem sawfly, we show a novel Spiroplasma species is ever-present and predominant, with phylogenomic analyses placing it as a member of the ixodetis clade of mollicutes. Using state-of-the-art metagenomic assembly and binning strategies we were able to reconstruct a 714 Kb, 72.7%-complete Spiroplasma genome, which represents just the second draft genome from the ixodetis clade of mollicutes. Functional annotation of the Spiroplasma genome indicated carbohydrate-metabolism involved PTS-mediated import of glucose and fructose followed by glycolysis to lactate, acetate, and propionoate. The bacterium also encoded biosynthetic pathways for essential vitamins B2, B3, and B9. We identified putative Spiroplasma virulence genes: cardiolipin and chitinase. These results identify a previously undescribed symbiosis between wheat stem sawfly and a novel Spiroplasma sp., availing insight into their molecular relationship, and may yield new opportunities for microbially-mediated pest control strategies.
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Affiliation(s)
- Carl J Yeoman
- Department of Animal & Range Sciences, Montana State University, Bozeman, MT, United States of America
| | - Laura M Brutscher
- Department of Animal & Range Sciences, Montana State University, Bozeman, MT, United States of America.,Department of Microbiology & Immunology, Montana State University, Bozeman, MT, United States of America
| | - Özcan C Esen
- Department of Medicine, University of Chicago, Chicago, IL, United States of America
| | - Furkan Ibaoglu
- Department of Animal & Range Sciences, Montana State University, Bozeman, MT, United States of America.,Department of Microbiology & Immunology, Montana State University, Bozeman, MT, United States of America
| | - Curtis Fowler
- Department of Animal & Range Sciences, Montana State University, Bozeman, MT, United States of America
| | - A Murat Eren
- Department of Medicine, University of Chicago, Chicago, IL, United States of America.,Marine Biological Laboratory, The Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Woods Hole, Massachuetts, United States of America
| | - Kevin Wanner
- Department of Plant Sciences & Plant Pathology, Montana State University, Bozeman, MT, United States of America
| | - David K Weaver
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, United States of America
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Varella AC, Weaver DK, Blake NK, Hofland ML, Heo HY, Cook JP, Lamb PF, Jordan KW, Akhunov E, Chao S, Talbert LE. Analysis of recombinant inbred line populations derived from wheat landraces to identify new genes for wheat stem sawfly resistance. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:2195-2207. [PMID: 31049630 DOI: 10.1007/s00122-019-03347-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/20/2019] [Indexed: 06/09/2023]
Abstract
Wheat landrace accessions were chosen from areas of the world with historical European wheat stem sawfly (Cephus pygmaeus L.) selection pressure to develop six recombinant inbred line (RIL) populations. Molecular maps were constructed, and resistance due to antibiosis and antixenosis was assessed at sites in Montana naturally infested by Cephus cinctus Norton, the wheat stem sawfly (WSS). Novel QTLs were identified along with QTL previously identified in elite germplasm. A newly identified QTL on chromosome 1B provided a new source for pith-filled solid stems. An allele for resistance on chromosome 4A unrelated to solid stems was identified in four of the six RIL populations. A landrace from Turkey, PI 166471, contained alleles at three QTLs causing high levels of larval mortality. None of the QTLs were related to stem solidness, but their combined effect provided resistance similar to that observed in a solid-stemmed check cultivar. These results show the utility of genetic populations derived from geographically targeted landrace accessions to identify new alleles for insect resistance. New PCR-based molecular markers were developed for introgression of novel alleles for WSS resistance into elite lines. Comparison of results with previous analysis of elite cultivars addresses changes in allele frequencies during the wheat breeding process.
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Affiliation(s)
- Andrea C Varella
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717, USA
| | - David K Weaver
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, 59717, USA
| | - Nancy K Blake
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717, USA
| | - Megan L Hofland
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, 59717, USA
| | - Hwa-Young Heo
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717, USA
| | - Jason P Cook
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717, USA
| | - Peggy F Lamb
- Department of Research Centers, Montana State University, Bozeman, MT, 59717, USA
| | - Katherine W Jordan
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Eduard Akhunov
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Shiaoman Chao
- Cereal Crops Research Unit, USDA-ARS, Fargo, ND, 58102, USA
| | - Luther E Talbert
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717, USA.
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Shrestha G, Briar SS, Reddy GV. Plant defense elicitors: plant fitness versus wheat stem sawfly. PeerJ 2018; 6:e5892. [PMID: 30402358 PMCID: PMC6215698 DOI: 10.7717/peerj.5892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 10/08/2018] [Indexed: 11/20/2022] Open
Abstract
The wheat stem sawfly (WSS), Cephus cinctus Norton, is an important wheat pest in the Northern Great Plains of the USA. No single control measure effectively suppresses WSS damage. This study provides information on the effects on the WSS adult settling preference behavior on wheat plants under laboratory conditions from treatment with both synthetic plant defense elicitors (Actigard® and cis-jasmone) and a botanical insecticide (Azadirachtin®). In addition, field experiments were performed to determine whether these chemicals impact the WSS fitness (larval mortality and larval body weight), winter wheat plant fitness (infestation, stem lodging, yield, and quality), adult population of WSS and Bracon spp., and larval parasitism levels. Our lab results showed that there were no significant differences in adult settling behavior on plants exposed separately to each chemical and control. In contrast, when adults were exposed simultaneously to treated and untreated plants, there was a significant reduction in the percentage of adults settling on Actigard® and Azadirachtin® treated plants compared to plants sprayed with water in the same cage. However, in field situations, regardless of application timing and field location, none of the chemicals significantly reduced adult population or stems damage. The exception was two times applications of Actigard® had significantly lower WSS infested stem damage levels at 30 days after initial treatment applications at Knees and 50 days at Choteau locations compared to control, but without effect at the Conrad location. The field study indicated that two times applications of Actigard® significantly increased diapausing larval mortality percentages and lowered stem lodging levels compared to untreated controls at Knees and Choteau locations, while no effects at Conrad location. Larval body weight was significantly lower in plots treated with Actigard® at Knees and Conrad, but no effects at Choteau. No significant differences were found in wheat yield and quality in plots treated with chemicals and controls at any location. Bracon spp. adult population and parasitism levels were not negatively affected by the use of chemicals. In conclusion, this study offers insights on what treatments should be emphasized in more detail despite variable findings.
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Affiliation(s)
- Govinda Shrestha
- Department of Research Centers, Western Triangle Agricultural Research Center, Montana State University, Conrad, MT, USA
| | - Shabeg S. Briar
- Department of Research Centers, Western Triangle Agricultural Research Center, Montana State University, Conrad, MT, USA
| | - Gadi V.P. Reddy
- Department of Research Centers, Western Triangle Agricultural Research Center, Montana State University, Conrad, MT, USA
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Varella AC, Talbert LE, Achhami BB, Blake NK, Hofland ML, Sherman JD, Lamb PF, Reddy GVP, Weaver DK. Characterization of Resistance to Cephus cinctus (Hymenoptera: Cephidae) in Barley Germplasm. JOURNAL OF ECONOMIC ENTOMOLOGY 2018; 111:923-930. [PMID: 29474649 PMCID: PMC6019026 DOI: 10.1093/jee/toy025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Most barley cultivars have some degree of resistance to the wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae). Damage caused by WSS is currently observed in fields of barley grown in the Northern Great Plains, but the impact of WSS damage among cultivars due to genetic differences within the barley germplasm is not known. Specifically, little is known about the mechanisms underlying WSS resistance in barley. We characterized WSS resistance in a subset of the spring barley CAP (Coordinated Agricultural Project) germplasm panel containing 193 current and historically important breeding lines from six North American breeding programs. Panel lines were grown in WSS infested fields for two consecutive years. Lines were characterized for stem solidness, stem cutting, WSS infestation (antixenosis), larval mortality (antibiosis), and parasitism (indirect plant defense). Variation in resistance to WSS in barley was compared to observations made for solid-stemmed resistant and hollow-stemmed susceptible wheat lines. Results indicate that both antibiosis and antixenosis are involved in the resistance of barley to the WSS, but antibiosis seems to be more prevalent. Almost all of the barley lines had greater larval mortality than the hollow-stemmed wheat lines, and only a few barley lines had mortality as low as that observed in the solid-stemmed wheat line. Since barley lines lack solid stems, it is apparent that barley has a different form of antibiosis. Our results provide information for use of barley in rotation to control the WSS and may provide a basis for identification of new approaches for improving WSS resistance in wheat.
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Affiliation(s)
- Andrea C Varella
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT
| | - Luther E Talbert
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT
| | - Buddhi B Achhami
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT
| | - Nancy K Blake
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT
| | - Megan L Hofland
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT
| | - Jamie D Sherman
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT
| | - Peggy F Lamb
- Department of Research Centers, Montana State University, Bozeman, MT
| | - Gadi V P Reddy
- Department of Research Centers, Montana State University, Bozeman, MT
| | - David K Weaver
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT
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Cagirici HB, Biyiklioglu S, Budak H. Assembly and Annotation of Transcriptome Provided Evidence of miRNA Mobility between Wheat and Wheat Stem Sawfly. FRONTIERS IN PLANT SCIENCE 2017; 8:1653. [PMID: 29038661 PMCID: PMC5630980 DOI: 10.3389/fpls.2017.01653] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/08/2017] [Indexed: 05/23/2023]
Abstract
Wheat Stem Sawfly (WSS), Cephus Cinctus Norton (Hymenoptera: Cephidae), is one of the most important pests, causing yield and economic losses in wheat and barley. The lack of information about molecular mechanisms of WSS for defeating plant's resistance prevents application of effective pest control strategies therefore, it is essential to identify the genes and their regulators behind WSS infestations. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are recognized with their regulatory functions on gene expression, tuning protein production by controlling transcriptional and post-transcriptional activities. A transcriptome-guided approach was followed in order to identify miRNAs, lncRNAs, and mRNA of WSS, and their interaction networks. A total of 1,893 were presented here as differentially expressed between larva and adult WSS insects. There were 11 miRNA families detected in WSS transcriptome. Together with the annotation of 1,251 novel mRNAs, the amount of genetic information available for WSS was expanded. The network between WSS miRNAs, lncRNAs, and mRNAs suggested miRNA-mediated regulatory roles of lncRNAs as competing endogenous RNAs. In the light of the previous evidence that small RNA molecules of a pathogen could suppress the immune response of host plant, we analyzed the putative interactions between larvae and wheat at the miRNA level. Overall, this study provides a profile of larva and adult WSS life stages in terms of coding and non-coding elements. These findings also emphasize the potential roles of wheat and larval miRNAs in wheat resistance to infestation and in the suppression of resistance which is critical for the development of effective pest control strategies.
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Affiliation(s)
- Halise B. Cagirici
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey
| | - Sezgi Biyiklioglu
- Cereal Genomics Lab, Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, United States
| | - Hikmet Budak
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey
- Cereal Genomics Lab, Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, United States
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High density mapping and haplotype analysis of the major stem-solidness locus SSt1 in durum and common wheat. PLoS One 2017; 12:e0175285. [PMID: 28399136 PMCID: PMC5388483 DOI: 10.1371/journal.pone.0175285] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/23/2017] [Indexed: 11/19/2022] Open
Abstract
Breeding for solid-stemmed durum (Triticum turgidum L. var durum) and common wheat (Triticum aestivum L.) cultivars is one strategy to minimize yield losses caused by the wheat stem sawfly (Cephus cinctus Norton). Major stem-solidness QTL have been localized to the long arm of chromosome 3B in both wheat species, but it is unclear if these QTL span a common genetic interval. In this study, we have improved the resolution of the QTL on chromosome 3B in a durum (Kofa/W9262-260D3) and common wheat (Lillian/Vesper) mapping population. Coincident QTL (LOD = 94-127, R2 = 78-92%) were localized near the telomere of chromosome 3BL in both mapping populations, which we designate SSt1. We further examined the SSt1 interval by using available consensus maps for durum and common wheat and compared genetic to physical intervals by anchoring markers to the current version of the wild emmer wheat (WEW) reference sequence. These results suggest that the SSt1 interval spans a physical distance of 1.6 Mb in WEW (positions 833.4-835.0 Mb). In addition, minor QTL were identified on chromosomes 2A, 2D, 4A, and 5A that were found to synergistically enhance expression of SSt1 to increase stem-solidness. These results suggest that developing new wheat cultivars with improved stem-solidness is possible by combining SSt1 with favorable alleles at minor loci within both wheat species.
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Portman SL, Krishnankutty SM, Reddy GVP. Entomopathogenic Nematodes Combined with Adjuvants Presents a New Potential Biological Control Method for Managing the Wheat Stem Sawfly, Cephus cinctus (Hymenoptera: Cephidae). PLoS One 2016; 11:e0169022. [PMID: 28006820 PMCID: PMC5179260 DOI: 10.1371/journal.pone.0169022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 12/10/2016] [Indexed: 11/18/2022] Open
Abstract
The wheat stem sawfly, (Cephus cinctus Norton) Hymenoptera: Cephidae, has been a major pest of winter wheat and barley in the northern Great Plains for more than 100 years. The insect’s cryptic nature and lack of safe chemical control options make the wheat stem sawfly (WSS) difficult to manage; thus, biological control offers the best hope for sustainable management of WSS. Entomopathogenic nematodes (EPNs) have been used successfully against other above-ground insect pests, and adding adjuvants to sprays containing EPNs has been shown to improve their effectiveness. We tested the hypothesis that adding chemical adjuvants to sprays containing EPNs will increase the ability of EPNs to enter wheat stems and kill diapausing WSS larvae. This is the first study to test the ability of EPNs to infect the WSS, C. cinctus, and test EPNs combined with adjuvants against C. cinctus in both the laboratory and the field. Infection assays showed that three different species of EPNs caused 60–100% mortality to WSS larvae. Adding Penterra, Silwet L-77, Sunspray 11N, or Syl-Tac to solutions containing EPNs resulted in higher WSS mortality than solutions made with water alone. Field tests showed that sprays containing S. feltiae added to 0.1% Penterra increased WSS mortality up to 29.1%. These results indicate a novel control method for WSS, and represent a significant advancement in the biological control of this persistent insect pest.
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Affiliation(s)
- Scott L. Portman
- Montana State University, Western Triangle Agricultural Research Center, Conrad, MT, United States of America
- * E-mail: (SLP); (GVPR)
| | | | - Gadi V. P. Reddy
- Montana State University, Western Triangle Agricultural Research Center, Conrad, MT, United States of America
- * E-mail: (SLP); (GVPR)
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10
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Szczepaniec A, Glover KD, Berzonsky W. Impact of Solid and Hollow Varieties of Winter and Spring Wheat on Severity of Wheat Stem Sawfly (Hymenoptera: Cephidae) Infestations and Yield and Quality of Grain. JOURNAL OF ECONOMIC ENTOMOLOGY 2015; 108:2316-2323. [PMID: 26453720 DOI: 10.1093/jee/tov207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 06/24/2015] [Indexed: 06/05/2023]
Abstract
Wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae), has recently emerged as a key pest of wheat (Triticum aestivum L.) in the Great Plains and Canadian provinces. The expanding impact of WSS has caused considerable economic losses to wheat production. Solid-stem varieties of wheat remain the only effective measure of suppression of WSS, and the goal of this research was to test whether five solid- and hollow-stem varieties of winter and spring wheat reduce survival of WSS in South Dakota. We reported that solid-stem varieties had significantly lower numbers of WSS larvae, and this effect was especially evident when WSS infestation rates exceeded 15%. We also observed that the yield of solid-stem varieties was significantly lower than hollow-stem varieties when the abundance of WSS was low, but not when populations of WSS were relatively high. We did not observe consistent differences in grain quality between solid- and hollow-stem varieties, however, and in case of protein levels of grain, solid-stem wheat varieties performed better than hollow-stem wheat. We conclude that solid-stem varieties of wheat appear to effectively suppress WSS survival, and reduced yield of these varieties is less apparent when populations of C. cinctus are high enough to affect the yield of hollow-stem wheat. This is the first report to describe the effectiveness of solid-stem varieties of wheat on WSS in South Dakota. More research in the state is necessary before more robust conclusions can be drawn.
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Affiliation(s)
- Adrianna Szczepaniec
- South Dakota State University, Plant Sciences Department, 244 SAG Box 2207A, Brookings, SD 57007.
| | - Karl D Glover
- South Dakota State University, Plant Sciences Department, 244 SAG Box 2207A, Brookings, SD 57007
| | - William Berzonsky
- South Dakota State University, Plant Sciences Department, 244 SAG Box 2207A, Brookings, SD 57007
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11
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Keren IN, Menalled FD, Weaver DK, Robison-Cox JF. Interacting agricultural pests and their effect on crop yield: application of a Bayesian decision theory approach to the joint management of Bromus tectorum and Cephus cinctus. PLoS One 2015; 10:e0118111. [PMID: 25692673 PMCID: PMC4333819 DOI: 10.1371/journal.pone.0118111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 12/18/2014] [Indexed: 12/03/2022] Open
Abstract
Worldwide, the landscape homogeneity of extensive monocultures that characterizes conventional agriculture has resulted in the development of specialized and interacting multitrophic pest complexes. While integrated pest management emphasizes the need to consider the ecological context where multiple species coexist, management recommendations are often based on single-species tactics. This approach may not provide satisfactory solutions when confronted with the complex interactions occurring between organisms at the same or different trophic levels. Replacement of the single-species management model with more sophisticated, multi-species programs requires an understanding of the direct and indirect interactions occurring between the crop and all categories of pests. We evaluated a modeling framework to make multi-pest management decisions taking into account direct and indirect interactions among species belonging to different trophic levels. We adopted a Bayesian decision theory approach in combination with path analysis to evaluate interactions between Bromus tectorum (downy brome, cheatgrass) and Cephus cinctus (wheat stem sawfly) in wheat (Triticum aestivum) systems. We assessed their joint responses to weed management tactics, seeding rates, and cultivar tolerance to insect stem boring or competition. Our results indicated that C. cinctus oviposition behavior varied as a function of B. tectorum pressure. Crop responses were more readily explained by the joint effects of management tactics on both categories of pests and their interactions than just by the direct impact of any particular management scheme on yield. In accordance, a C. cinctus tolerant variety should be planted at a low seeding rate under high insect pressure. However as B. tectorum levels increase, the C. cinctus tolerant variety should be replaced by a competitive and drought tolerant cultivar at high seeding rates despite C. cinctus infestation. This study exemplifies the necessity of accounting for direct and indirect biological interactions occurring within agroecosystems and propagating this information from the statistical analysis stage to the management stage.
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Affiliation(s)
- Ilai N. Keren
- Washington Department of Fish and Wildlife, Olympia, Washington, United States of America
| | - Fabian D. Menalled
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, United States of America
- * E-mail:
| | - David K. Weaver
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, United States of America
| | - James F. Robison-Cox
- Department of Mathematical Sciences, Montana State University, Bozeman, Montana, United States of America
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Gress JC, Robertson HM, Weaver DK, Dlakić M, Wanner KW. Odorant receptors of a primitive hymenopteran pest, the wheat stem sawfly. INSECT MOLECULAR BIOLOGY 2013; 22:659-667. [PMID: 23964849 DOI: 10.1111/imb.12053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The wheat stem sawfly, Cephus cinctus, is an herbivorous hymenopteran that feeds exclusively on members of the Graminae family. Synanthropically, it has become one of the most important insect pests of wheat grown in the northern Great Plains region of the USA and Canada. Insecticides are generally ineffective because of the wheat stem sawfly's extended adult flight period and its inaccessible larval stage, during which it feeds within the wheat stems, making it virtually intractable to most pest management strategies. While research towards integrated pest management strategies based on insect olfaction has proved promising, nothing is known about the molecular basis of olfaction in this important pest species. In this study we identified 28 unique odorant receptor (Or) transcripts from an antennal transcriptome. A phylogenetic analysis with the predicted Ors from the honey bee and jewel wasp genomes revealed at least four clades conserved amongst all three Hymenoptera species. Antennal expression levels were analysed using quantitative real-time PCR, and one male-biased and five female-biased Ors were identified. This study provides the basis for future functional analyses to identify behaviourally active odours that can be used to help develop olfactory-mediated pest management tools.
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Affiliation(s)
- J C Gress
- Department of Plant Sciences & Plant Pathology, Montana State University, Bozeman, MT, USA
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