scholarly journals Aggregation pheromone of coconut rhinoceros beetle,Oryctes rhinoceros (L.) (coleoptera: Scarabaeidae)

1995 ◽  
Vol 21 (10) ◽  
pp. 1549-1570 ◽  
Author(s):  
Rebecca H. Hallett ◽  
Alice L. Perez ◽  
Gerhard Gries ◽  
Regine Gries ◽  
Harold D. Pierce ◽  
...  
Keyword(s):  
Aggregation Pheromone ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle

scholarly journals Aggregation Pheromone of the Guam Strain of Coconut Rhinoceros Beetle, Oryctes Rhinoceros, and Revision of Stereochemistry

2021 ◽  
Author(s):  
David R Hall ◽  
Steven J Harte ◽  
Dudley I Farman ◽  
Mark Ero ◽  
Alfred Pokana
Keyword(s):  
Aggregation Pheromone ◽  
Field Trapping ◽  
Ethyl Esters ◽  
Male And Female ◽  
Tropical Asia ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
Virgin Male ◽  
Female Specific ◽  
Male Specific

Abstract The coconut rhinoceros beetle, Oryctes rhinoceros (Linnaeus 1758) (Coleoptera: Scarabaeidae: Dynastinae) (CRB), is endemic to tropical Asia where it damages both coconut and oil palm. A new invasion by CRB occurred on Guam in 2007 and eradication attempts failed using commonly applied O. rhinoceros nudivirus (OrNV) isolates. This and subsequent invasive outbreaks were found to have been caused by a previously unrecognized haplotype, CRB-G, which appeared to be tolerant to OrNV. The male-produced aggregation pheromone of the endemic, susceptible strain of O. rhinoceros (CRB-S) was previously identified as ethyl 4-methyloctanoate. There were anecdotal reports that the commercial lures containing this compound were not attractive to CRB-G and the aim of this work was to identify the pheromone of CRB-G. Initial collections of volatiles from virgin male and female CRB-G adults failed to show any male- or female-specific compounds as candidate pheromone components. Only after five months were significant quantities of ethyl 4-methyloctanoate and 4-methyloctanoic acid produced by males but not by females. No other male-specific compounds could be detected, in particular methyl 4-methyloctanoate, 4-methyl-1-octanol or 4-methyl-1-octyl acetate, compounds identified in volatiles from some other species of Oryctes. Ethyl 4-methyloctanoate elicited a strong electroantennogram response from both male and female CRB-G, but these other compounds, including 4-methyloctanoic acid, did not. The enantiomers of ethyl 4-methyloctanoate and 4-methyloctanoic acid were conveniently prepared by enzymatic resolution of the commercially-available acid, and the enantiomers of the acid, but not the ester, could be separated by gas chromatography on an enantiospecific cyclodextrin phase. Using this approach, both the ethyl 4-methyloctanoate and the 4-methyloctanoic acid produced by male CRB-G were shown to be exclusively the (R)-enantiomers whereas previous reports had suggested male CRB-S produced the (S)-enantiomers. However, re-examination of the ester and acid produced by male CRB-S showed that these were also the (R)-enantiomers. In field trapping experiments, both racemic and ethyl (R)-4-methyloctanoate were highly attractive to both male and female CRB-G. The (S)-enantiomer and the corresponding acids were only weakly attractive. Addition of racemic 4-methyloctanoic acid to ethyl 4-methyloctanoate did significantly increase attractiveness, but addition of (R)- or (S)-4-methyloctanoic acid to the corresponding ethyl esters did not. Reasons for the previous misassignment of the configuration of the components of the CRB-S pheromone are discussed along with the practical implications of these results.

scholarly journals Identification of Components of the Aggregation Pheromone of the Guam Strain of Coconut Rhinoceros Beetle, Oryctes rhinoceros, and Determination of Stereochemistry

2021 ◽  
Author(s):  
David R. Hall ◽  
Steven J. Harte ◽  
Dudley I. Farman ◽  
Mark Ero ◽  
Alfred Pokana
Keyword(s):  
Aggregation Pheromone ◽  
Solomon Islands ◽  
Field Trapping ◽  
Ethyl Esters ◽  
Male And Female ◽  
Tropical Asia ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
The Difference ◽  
Female Specific

AbstractThe coconut rhinoceros beetle, Oryctes rhinoceros (Linnaeus 1758) (Coleoptera: Scarabaeidae: Dynastinae) (CRB), is endemic to tropical Asia where it damages both coconut and oil palm. A new invasion by CRB occurred on Guam in 2007 and eradication attempts failed using commonly applied Oryctes rhinoceros nudivirus (OrNV) isolates. This and subsequent invasive outbreaks were found to have been caused by a previously unrecognized haplotype, CRB-G, which appeared to be tolerant to OrNV. The male-produced aggregation pheromone of the endemic, susceptible strain of O. rhinoceros (CRB-S) was previously identified as ethyl 4-methyloctanoate. Following reports from growers that commercial lures containing this compound were not attractive to CRB-G, the aim of this work was to identify the pheromone of CRB-G. Initial collections of volatiles from virgin male and female CRB-G adults from the Solomon Islands failed to show any male- or female-specific compounds as candidate pheromone components. Only after five months were significant quantities of ethyl 4-methyloctanoate and 4-methyloctanoic acid produced by males but not by females. No other male-specific compounds could be detected, in particular methyl 4-methyloctanoate, 4-methyl-1-octanol, or 4-methyl-1-octyl acetate, compounds identified in volatiles from some other species of Oryctes. Ethyl 4-methyloctanoate elicited a strong electroantennogram response from both male and female CRB-G, but these other compounds, including 4-methyloctanoic acid, did not. The enantiomers of ethyl 4-methyloctanoate and 4-methyloctanoic acid were conveniently prepared by enzymatic resolution of the commercially-available acid, and the enantiomers of the acid, but not the ester, could be separated by gas chromatography on an enantioselective cyclodextrin phase. Using this approach, both ethyl 4-methyloctanoate and 4-methyloctanoic acid produced by male CRB-G were shown to be exclusively the (R)-enantiomers whereas previous reports had suggested male O. rhinoceros produced the (S)-enantiomers. However, re-examination of the ester and acid produced by male CRB-S from Papua New Guinea showed that these were also the (R)-enantiomers. In field trapping experiments carried out in the Solomon Islands, both racemic and ethyl (R)-4-methyloctanoate were highly attractive to both male and female CRB-G beetles. The (S)-enantiomer and the corresponding acids were only weakly attractive. The addition of racemic 4-methyloctanoic acid to ethyl 4-methyloctanoate did significantly increase attractiveness, but the addition of (R)- or (S)-4-methyloctanoic acid to the corresponding ethyl esters did not. Possible reasons for the difference in assignment of configuration of the components of the CRB pheromone are discussed along with the practical implications of these results.

scholarly journals Genomic structural and transcriptional variation of Oryctes rhinoceros nudivirus (OrNV) in Coconut Rhinoceros Beetle

2020 ◽  
Author(s):  
Kayvan Etebari ◽  
Rhys Parry ◽  
Marie Joy B. Beltran ◽  
Michael J. Furlong
Keyword(s):  
Gene Expression ◽  
Solomon Islands ◽  
Dna Helicase ◽  
The Philippines ◽  
Comparative Genomic ◽  
Viral Gene ◽  
Geographic Population ◽  
Oryctes Rhinoceros ◽  
Synonymous Mutations ◽  
Rhinoceros Beetle

AbstractOryctes rhinoceros nudivirus (OrNV) is a large circular double-stranded DNA virus which has been used as a biological control agent to suppress Coconut Rhinoceros Beetle (Oryctes rhinoceros) in Southeast Asia and the Pacific Islands. Recently a new wave of O. rhinoceros incursions in Oceania in previously non-infested areas is thought to be related to the presence of low virulence isolates of OrNV or virus tolerant haplotypes of beetles. In this study, chronically infected O. rhinoceros adults were field collected from the Philippines, Fiji, Papua New Guinea and the Solomon Islands. We extracted total RNA from these samples to investigate the global viral gene expression profiles and comparative genomic analysis of structural variations between the four different populations. Maximum likelihood phylogenic analysis indicated that OrNV strains from the Solomon Islands and the Philippines are closely related to while OrNV strains from PNG and Fiji formed a distinct adjacent clade. We detected several polymorphic sites with a frequency higher than 35% in 892 positions of the viral genome. The highest number of structural variants, including single nucleotide variants (SNV), insertion, deletion and non-synonymous mutations, were found in strains from Fiji and PNG when compared to complete recently sequenced Solomon Islands OrNV reference genome. Non-synonymous mutations were detected in several hypothetical proteins, and 15 nudivirus core genes such as OrNV_gp034 (DNA Helicase), lef-8, lef-4 and vp91. For examination of the global gene expression profile of OrNV in chronically infected populations, we found limited evidence of variation between geographic populations. Only a few genes such as OrNV_gp01 (DNA polymerase B), OrNV_gp022 and OrNV_gp107 (Pif-3) were differentially expressed among different strains. Additionally, small RNA sequencing from the Solomon Islands population suggests that OrNV is targeted by the host RNA interference (RNAi) response with abundant 21nt small RNAs. Additionally, we identified a highly abundant putative 22 nt miRNA from the 3’ of a pre-miRNA-like hairpin originating from OrNV-gp-098. These findings provide valuable resources for future studies to improve our understanding of the OrNV genetic variation. Some of these structural changes are specific to the geographic population and could be related to particular phenotypic characteristics of the strain, such as viral pathogenicity or transmissibility, and this requires further investigation.

scholarly journals Genetic structure of the Coconut Rhinoceros Beetle (Oryctes rhinoceros) population and the incidence of its biocontrol agent (Oryctes rhinoceros nudivirus) in the South Pacific Islands

2020 ◽  
Author(s):  
Kayvan Etebari ◽  
James Hereward ◽  
Apenisa Sailo ◽  
Emeline M Ahoafi ◽  
Robert Tautua ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
New Caledonia ◽  
Solomon Islands ◽  
South Pacific ◽  
The Philippines ◽  
Mitochondrial Lineage ◽  
The South ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
The Pacific

Incursions of the Coconut rhinoceros beetle (CRB), Oryctes rhinoceros, have been detected in several countries of the south-west Pacific in recent years, resulting in an expansion of the pest's geographic range. It has been suggested that this resurgence is related to an O. rhinoceros mitochondrial lineage (previously referred to as the CRB-G biotype) that is reported to show reduced susceptibility to the well-established classical biocontrol agent, Oryctes rhinoceros nudivirus (OrNV). We investigated O. rhinoceros population genetics and the OrNV status of adult specimens collected in the Philippines and seven different South Pacific island countries (Fiji, New Caledonia, Papua New Guinea (PNG), Samoa, Solomon Islands, Tonga, and Vanuatu). Based on the presence of single nucleotide polymorphisms (snps) in the mitochondrial Cytochrome C Oxidase subunit I (CoxI) gene, we found three major mitochondrial lineages (CRB-G, a PNG lineage (CRB-PNG) and the South Pacific lineage (CRB-S)) across the region. Haplotype diversity varied considerably between and within countries. The O. rhinoceros population in most countries was monotypic and all individuals tested belonged to a single mitochondrial lineage (Fiji, CRB-S; Tonga, CRB-S; Vanuatu, CRB-PNG; PNG (Kimbe), CRB-PNG; New Caledonia CRB-G; Philippines, CRB-G). However, in Samoa we detected CRB-S and CRB-PNG and in Solomon Islands we detected all three haplotype groups. Genotyping-by-Sequencing (GBS) methods were used to genotype 10,000 snps from 230 insects across the Pacific and showed genetic differentiation in the O. rhinoceros nuclear genome among different geographical populations. The GBS data also provided evidence for gene flow and admixture between different haplotypes in Solomon Islands. Therefore, contrary to earlier reports, CRB-G is not solely responsible for damage to the coconut palms reported since the pest was first recorded in Solomon Islands in 2015. We also PCR-screened a fragment of OrNV from 260 insects and detected an extremely high prevalence of viral infection in all three haplotypes in the region. We conclude that the haplotype groups CRB-G, CRB-S, and PNG, do not represent biotypes, subspecies, or cryptic species, but simply represent different invasions of O. rhinoceros across the Pacific. This has important implications for management, especially biological control, of Coconut rhinoceros beetle in the region.

scholarly journals Transcription Profile and Genomic Variations of Oryctes Rhinoceros Nudivirus in Coconut Rhinoceros Beetles

2020 ◽  
Vol 94 (22) ◽  
Author(s):  
Kayvan Etebari ◽  
Rhys Parry ◽  
Marie Joy B. Beltran ◽  
Michael J. Furlong
Keyword(s):  
Gene Expression ◽  
Southeast Asia ◽  
Pacific Islands ◽  
Biocontrol Agent ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Content Type ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
The Pacific

ABSTRACT Oryctes rhinoceros nudivirus (OrNV) is a double-stranded DNA (dsDNA) virus which has been used as a biocontrol agent to suppress the coconut rhinoceros beetle (Oryctes rhinoceros) in Southeast Asia and the Pacific Islands. A new wave of O. rhinoceros incursions in Oceania is thought to be related to the presence of low-virulence isolates of OrNV or virus-tolerant haplotypes of beetles. In this study, chronically infected beetles were collected from Philippines, Fiji, Papua New Guinea (PNG), and the Solomon Islands (SI). RNA sequencing (RNA-seq) was performed to investigate the global viral gene expression profiles and for comparative genomic analysis of structural variations. Maximum likelihood phylogenic analysis indicated that OrNV strains from the SI and Philippines are closely related, while OrNV strains from PNG and Fiji formed a distinct adjacent clade. We detected several polymorphic sites with a frequency higher than 35% in 892 positions of the viral genome. Nonsynonymous mutations were detected in several hypothetical proteins and 15 nudivirus core genes, such as gp034, lef-8, lef-4, and vp91. We found limited evidence of variation in viral gene expression among geographic populations. Only a few genes, such as gp01, gp022, and gp107, were differentially expressed among different strains. Additionally, small RNA sequencing from the SI population suggested that OrNV is targeted by the host RNA interference (RNAi) response with abundant 21-nucleotide small RNAs. Some of these genomic changes are specific to the geographic population and could be related to particular phenotypic characteristics of the strain, such as viral pathogenicity or transmissibility, and this requires further investigation. IMPORTANCE Oryctes rhinoceros nudivirus has been an effective biocontrol agent against the coconut rhinoceros beetle in Southeast Asia and the Pacific Islands for decades. The recent outbreak of these beetles in many South Pacific islands has had a significant impact on livelihoods in the region. It has been suggested that the resurgence and spread of the pest are related to the presence of low-virulence isolates of OrNV or virus-tolerant haplotypes of beetles. We examined viral genomic and transcriptional variations in chronically infected beetles from different geographical populations. A high number of polymorphic sites among several geographical strains of OrNV were identified, but potentially only a few of these variations in the genome are involved in functional changes and can potentially alter the typical function. These findings provide valuable resources for future studies to improve our understanding of the OrNV genetic variations in different geographic regions and their potential link to virus pathogenicity.

scholarly journals Oviposition Preferences and Behavior of Wild-Caught and Laboratory-Reared Coconut Rhinoceros Beetle, Oryctes rhinoceros (Coleoptera: Scarabaeidae), in Relation to Substrate Particle Size

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 141 ◽  
Author(s):  
Megan Manley ◽  
Michael Melzer ◽  
Helen Spafford
Keyword(s):  
Particle Size ◽  
Oviposition Behavior ◽  
Particle Sizes ◽  
Breeding Sites ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
Oviposition Preferences ◽  
Choice Tests ◽  
And Behavior ◽  
Substrate Particle

The coconut rhinoceros beetle (CRB), Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae), has become one of the most important coconut and oil palm pests. This species was detected attacking coconut palms on Oʻahu, Hawaiʻi in December 2013, and an eradication program was initiated. One of the major challenges for eradication has been the identification of new breeding sites. Information on the factors influencing oviposition is needed to aid in finding sites likely to host the immature stages of this insect. In this study, a series of choice tests were conducted to assess the oviposition preferences of both laboratory-reared and wild-caught CRB. Mated females, of both lab-reared and wild-caught beetles, were offered for oviposition a choice between sand and two mulch substrates, one with small and one with large particle sizes. Both types of CRB laid eggs preferentially in substrate of small particle size rather than large and none laid eggs in sand. Lab-reared and wild-caught CRB differed in their oviposition behavior and size. These results can be used to aid in the identification of breeding sites for management programs and eradication efforts.

Sign in / Sign up

Export Citation Format

Share Document