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Anastasia Kampouraki - One of the best experts on this subject based on the ideXlab platform.
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functional genomics of a symbiotic community shared traits in the Olive Fruit Fly gut microbiota
bioRxiv, 2019Co-Authors: Frances Blow, Anastasia Gioti, Ian Goodhead, Maria Kalyva, Anastasia Kampouraki, John VontasAbstract:The Olive Fruit Fly Bactrocera oleae is a major pest of Olives worldwide and houses a specialized gut microbiota dominated by the obligate symbiont "Candidatus Erwinia dacicola". Ca. E. dacicola is required for juvenile development in ripening Olives and is thought to supplement dietary nitrogen in adults, with only indirect evidence for this hypothesis so far. Here, we sought to functionally investigate the symbiosis and its contribution to insect fitness. Inspection of three available Ca. E. dacicola genomes and one transcriptome provided evidence that the symbiont can hydrolyze urea for use as a nitrogen source, most probably by the adult insect: A conserved urease operon was identified, not expressed at the juvenile stage, for which we provide evidence for a likely acquisition by horizontal gene transfer. Moreover, to explore the ecology of the B. oleae gut, we examined the composition of bacterial communities associated with Olive Fruit Fly populations from Crete. We identified and reconstructed the genome of the novel species Tatumella sp. TA1, which is a stable component of the Mediterranean Olive Fruit Fly microbiota. We further detected, in the genomes of both obligate and facultative members of the gut microbiota, components of extracellular surface structures, which may mediate interactions with the host and between microbes, including the exchange of genetic material. Our findings suggest that urea hydrolysis is a conserved functional trait for microbes stably inhabiting the B. oleae gut, and that genetic exchanges between microbes may have shaped the symbiosis between B. oleae and Ca. E. dacicola.
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recent evolution and operational impact of insecticide resistance in Olive Fruit Fly bactrocera oleae populations from greece
Journal of Pest Science, 2018Co-Authors: Anastasia Kampouraki, Antonios Chrysargyris, Marianna Stavrakaki, Aggeliki Karataraki, Georgios Katsikogiannis, Evanthia Pitika, Kiriaki Varikou, Antonia Vlachaki, Eleni MalandrakiAbstract:The major problem of Olive Fruit protection in the Mediterranean basin is the control of the Olive Fruit Fly Bactrocera oleae. The aim of this study was to investigate the status of resistance against insecticides which are registered and used against this major Olive pest in Greece. During a 9-year survey, 55 B. oleae populations were collected. Insecticide application records showed extensive use of pyrethroids (alpha-cypermethrin) and to a lesser extent macrocyclic lactones (spinosad) and organophosphates (dimethoate). Low-to-moderate resistance levels were identified in the majority of populations for alpha-cypermethrin until 2012. After 2013, however, a dramatic increase of alpha-cypermethrin resistance was observed, especially in populations from Crete, Greece. The phenotype has an obvious impact on control efficacy. In real-field-cage trials, the mortality of the pyrethroid resistant field population from Crete was dramatically lower compared to the mortality of a respective field population from Samos with low-resistance level. Low-resistance levels were observed for spinosad in most of the populations tested. The frequency of the organophosphate resistance mutations G488S and I214V remained very high across most populations in Greece, despite the reduction in the application of these insecticides in the last decade. In contrast, the frequency of the mutation Δ3Q was very low. In conclusion, field evolved and practical resistance against alpha-cypermethrin seems to be emerging in B. oleae populations from Greece. It needs to be monitored and further characterised for the application of evidence-based control strategies.
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transcriptomic responses of the Olive Fruit Fly bactrocera oleae and its symbiont candidatus erwinia dacicola to Olive feeding
Scientific Reports, 2017Co-Authors: Boaz Yuval, Michael Benyosef, Nena Pavlidi, Wannes Dermauw, Anastasia Gioti, Anastasia Kampouraki, Nicky Wybouw, Edouard JurkevichAbstract:The Olive Fruit Fly, Bactrocera oleae, is the most destructive pest of Olive orchards worldwide. The monophagous larva has the unique capability of feeding on Olive mesocarp, coping with high levels of phenolic compounds and utilizing non-hydrolyzed proteins present, particularly in the unripe, green Olives. On the molecular level, the interaction between B. oleae and Olives has not been investigated as yet. Nevertheless, it has been associated with the gut obligate symbiotic bacterium Candidatus Erwinia dacicola. Here, we used a B.oleae microarray to analyze the gene expression of larvae during their development in artificial diet, unripe (green) and ripe (black) Olives. The expression profiles of Ca. E. dacicola were analyzed in parallel, using the Illumina platform. Several genes were found overexpressed in the Olive Fly larvae when feeding in green Olives. Among these, a number of genes encoding detoxification and digestive enzymes, indicating a potential association with the ability of B. oleae to cope with green Olives. In addition, a number of biological processes seem to be activated in Ca. E. dacicola during the development of larvae in Olives, with the most notable being the activation of amino-acid metabolism.
John Vontas - One of the best experts on this subject based on the ideXlab platform.
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Efficient genome editing in the Olive Fruit Fly, Bactrocera oleae.
Insect molecular biology, 2020Co-Authors: Venetia Koidou, Shane Denecke, Panagiotis Ioannidis, I. Vlatakis, Ioannis Livadaras, John VontasAbstract:The Olive Fruit Fly, Bactrocera oleae, causes great damage to the quality and quantity of Olive production worldwide. Pest management approaches have proved difficult for a variety of reasons, a fact that has brought about a need for alternative tools and approaches. Here we report for the first time in B. oleae the development of the clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) gene editing tool, using the well-known eye colour marker gene scarlet. Two synthetic guide RNAs targeting the coding region of the scarlet gene were synthesized and shown to work efficiently in vitro. These reagents were then microinjected along with purified Cas9 protein into early-stage embryos. Successful CRISPR-induced mutations of both copies of the scarlet gene showed a striking yellow eye phenotype, indicative of gene disruption. Multiple successful CRISPR events were confirmed by PCR and sequencing. The establishment of an efficient CRISPR-based gene editing tool in B. oleae will enable the study of critical molecular mechanisms in Olive Fruit Fly biology and physiology, including the analysis of insecticide resistance mechanisms and the discovery of novel insecticide targets, as well as facilitate the development of novel biotechnology-based pest control strategies.
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functional genomics of a symbiotic community shared traits in the Olive Fruit Fly gut microbiota
bioRxiv, 2019Co-Authors: Frances Blow, Anastasia Gioti, Ian Goodhead, Maria Kalyva, Anastasia Kampouraki, John VontasAbstract:The Olive Fruit Fly Bactrocera oleae is a major pest of Olives worldwide and houses a specialized gut microbiota dominated by the obligate symbiont "Candidatus Erwinia dacicola". Ca. E. dacicola is required for juvenile development in ripening Olives and is thought to supplement dietary nitrogen in adults, with only indirect evidence for this hypothesis so far. Here, we sought to functionally investigate the symbiosis and its contribution to insect fitness. Inspection of three available Ca. E. dacicola genomes and one transcriptome provided evidence that the symbiont can hydrolyze urea for use as a nitrogen source, most probably by the adult insect: A conserved urease operon was identified, not expressed at the juvenile stage, for which we provide evidence for a likely acquisition by horizontal gene transfer. Moreover, to explore the ecology of the B. oleae gut, we examined the composition of bacterial communities associated with Olive Fruit Fly populations from Crete. We identified and reconstructed the genome of the novel species Tatumella sp. TA1, which is a stable component of the Mediterranean Olive Fruit Fly microbiota. We further detected, in the genomes of both obligate and facultative members of the gut microbiota, components of extracellular surface structures, which may mediate interactions with the host and between microbes, including the exchange of genetic material. Our findings suggest that urea hydrolysis is a conserved functional trait for microbes stably inhabiting the B. oleae gut, and that genetic exchanges between microbes may have shaped the symbiosis between B. oleae and Ca. E. dacicola.
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analysis of the Olive Fruit Fly bactrocera oleae transcriptome and phylogenetic classification of the major detoxification gene families
PLOS ONE, 2013Co-Authors: Nena Pavlidi, Wannes Dermauw, Stephane Rombauts, Antonis Chrisargiris, Thomas Van Leeuwen, John VontasAbstract:The Olive Fruit Fly Bactrocera oleae has a unique ability to cope with Olive flesh, and is the most destructive pest of Olives worldwide. Its control has been largely based on the use of chemical insecticides, however, the selection of insecticide resistance against several insecticides has evolved. The study of detoxification mechanisms, which allow the Olive Fruit Fly to defend against insecticides, and/or phytotoxins possibly present in the mesocarp, has been hampered by the lack of genomic information in this species. In the NCBI database less than 1,000 nucleotide sequences have been deposited, with less than 10 detoxification gene homologues in total. We used 454 pyrosequencing to produce, for the first time, a large transcriptome dataset for B. oleae. A total of 482,790 reads were assembled into 14,204 contigs. More than 60% of those contigs (8,630) were larger than 500 base pairs, and almost half of them matched with genes of the order of the Diptera. Analysis of the Gene Ontology (GO) distribution of unique contigs, suggests that, compared to other insects, the assembly is broadly representative for the B. oleae transcriptome. Furthermore, the transcriptome was found to contain 55 P450, 43 GST-, 15 CCE- and 18 ABC transporter-genes. Several of those detoxification genes, may putatively be involved in the ability of the Olive Fruit Fly to deal with xenobiotics, such as plant phytotoxins and insecticides. In summary, our study has generated new data and genomic resources, which will substantially facilitate molecular studies in B. oleae, including elucidation of detoxification mechanisms of xenobiotic, as well as other important aspects of Olive Fruit Fly biology.
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control of the Olive Fruit Fly using genetics enhanced sterile insect technique
BMC Biology, 2012Co-Authors: Martha Koukidou, John Vontas, Polychronis Rempoulakis, Aris Economopoulos, Hong Fei Gong, Luke AlpheyAbstract:Background The Olive Fruit Fly, Bactrocera oleae, is the major arthropod pest of commercial Olive production, causing extensive damage to Olive crops worldwide. Current control techniques rely on spraying of chemical insecticides. The sterile insect technique (SIT) presents an alternative, environmentally friendly and species-specific method of population control. Although SIT has been very successful against other tephritid pests, previous SIT trials on Olive Fly have produced disappointing results. Key problems included altered diurnal mating rhythms of the laboratory-reared insects, resulting in asynchronous mating activity between the wild and released sterile populations, and low competitiveness of the radiation-sterilised mass-reared flies. Consequently, the production of competitive, male-only release cohorts is considered an essential prerequisite for successful Olive Fly SIT.
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detection of resistance associated point mutations of organophosphate insensitive acetylcholinesterase in the Olive Fruit Fly bactrocera oleae gmelin
Pesticide Biochemistry and Physiology, 2005Co-Authors: Nicola J Hawkes, Janet Hemingway, Robert W Janes, John VontasAbstract:We have recently identified two resistance-associated point mutations of organophosphate (OP)-insensitive acetylcholinesterase in the Olive Fruit Fly Bactrocera oleae, the most important Olive orchard pest world-wide. We have developed simple PCR-restriction fragment length polymorphism assays for each mutation, utilising an AccI restriction site created by Ile214Val, and a BssHII restriction site destroyed by a neutral change always accompanying the second mutation Gly488Ser. Samples from Greece homozygous for both mutations proved the most insensitive to dimethoate. The frequencies of these mutations in field-collected samples from several countries were investigated. Ninety-three percent of samples from Greece and Albania, where OPs have been extensively used in B. oleae control, were homozygous for both mutations. Resistance-associated alleles were detected at lower frequencies, but still with both mutations in conjunction in the majority of cases, in western Mediterranean countries with limited use of OPs. Samples from South Africa, however, did not have either of the resistance-associated mutations. The double mutation haplotype clearly confers a strong selective advantage in field populations of B. oleae exposed to OPs.
Kostas D. Mathiopoulos - One of the best experts on this subject based on the ideXlab platform.
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decoding the reproductive system of the Olive Fruit Fly bactrocera oleae
Genes, 2021Co-Authors: Mariaeleni Gregoriou, Konstantina T. Tsoumani, Evi G Kakani, Martin Reczko, Kostas D. MathiopoulosAbstract:In most diploid organisms, mating is a prerequisite for reproduction and, thus, critical to the maintenance of their population and the perpetuation of the species. Besides the importance of understanding the fundamentals of reproduction, targeting the reproductive success of a pest insect is also a promising method for its control, as a possible manipulation of the reproductive system could affect its destructive activity. Here, we used an integrated approach for the elucidation of the reproductive system and mating procedures of the Olive Fruit Fly, Bactrocera oleae. Initially, we performed a RNAseq analysis in reproductive tissues of virgin and mated insects. A comparison of the transcriptomes resulted in the identification of genes that are differentially expressed after mating. Functional annotation of the genes showed an alteration in the metabolic, catalytic, and cellular processes after mating. Moreover, a functional analysis through RNAi silencing of two differentially expressed genes, yellow-g and troponin C, resulted in a significantly reduced oviposition rate. This study provided a foundation for future investigations into the Olive Fruit Fly’s reproductive biology to the development of new exploitable tools for its control.
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targeted somatic mutagenesis through crispr cas9 ribonucleoprotein complexes in the Olive Fruit Fly bactrocera oleae
Archives of Insect Biochemistry and Physiology, 2020Co-Authors: Kostas D. Mathiopoulos, Angela Meccariello, Konstantina T. Tsoumani, Andrea Gravina, Pasquale Primo, Martina Buonanno, Giuseppe SacconeAbstract:The Olive Fruit Fly, Bactrocera oleae (Diptera: Tephritidae), is the most destructive insect pest of Olive cultivation, causing significant economic and production losses. Here, we present the establishment of the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 methodology for gene disruption in this species. We performed targeted mutagenesis of the autosomal gene white (Bo-we), by injecting into early embryos in vitro preassembled and solubilized Cas9 ribonucleoprotein complexes loaded with two gene-specific single-guide RNAs. Gene disruption of Bo-we led to somatic mosaicism of the adult eye color. Large eye patches or even an entire eye lost the iridescent reddish color, indicating the successful biallelic mutagenesis in somatic cells. Cas9 induced either indels in each of the two simultaneously targeted Bo-we sites or a large deletion of the intervening region. This study demonstrates the first efficient implementation of the CRISPR/Cas9 technology in the Olive Fly, providing new opportunities towards the development of novel genetic tools for its control.
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detection and geographical distribution of the organophosphate resistance associated δ3q ace mutation in the Olive Fruit Fly bactrocera oleae rossi
Pest Management Science, 2014Co-Authors: Evi G Kakani, Ioannis M. Ioannides, Efthymia Sagri, Michalis Omirou, Kostas D. MathiopoulosAbstract:BACKGROUND The Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), is the most important pest of Olives. Its control is based mostly on organophosphate (OP) insecticides, a practice that has led to resistance development. OP resistance in B. oleae has been associated with three mutations in the acetylcholinesterase (AChE), the product of ace gene. The current study presents new diagnostic tests for the detection of the ace mutations and aims at monitoring the frequency of the Δ3Q mutation, which appears associated with resistance at higher OP doses in natural Olive Fly populations. RESULTS An allele-specific polymerase chain reaction (PCR), a PCR-RFLP (restriction fragment length polymorphism) and a Taq-Man test were developed for the Δ3Q mutation detection and a new duplex quantitative PCR assay was designed for the G488S and I214V mutations. Moreover, the frequency of Δ3Q mutation was examined in ten populations of eight countries around the Mediterranean basin. The highest frequencies (10%) were found in Greece and Italy, whereas a gradual decrease of Δ3Q frequency towards the western Mediterranean was noted. CONCLUSION Robust tests for insecticide resistance mutations at their incipient levels are essential tools to monitor the increase and geographical spread of such mutations. Three different tests were developed for AChE-Δ3Q that indicated its association with OP applications across the Mediterranean. © 2013 Society of Chemical Industry
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Genomic structure, organization and localization of the acetylcholinesterase locus of the Olive Fruit Fly, Bactrocera oleae.
Bulletin of entomological research, 2012Co-Authors: Evi G Kakani, Elena Drosopoulou, Penelope Mavragani-tsipidou, M. Trakala, Kostas D. MathiopoulosAbstract:Acetylcholinesterase (AChE), encoded by the ace gene, is a key enzyme of cholinergic neurotransmission. Insensitive acetylcholinesterase (AChE) has been shown to be responsible for resistance to OPs and CBs in a number of arthropod species, including the most important pest of Olives trees, the Olive Fruit Fly Bactrocera oleae. In this paper, the organization of the B. oleae ace locus, as well as the structural and functional features of the enzyme, are determined. The organization of the gene was deduced by comparison to the ace cDNA sequence of B. oleae and the organization of the locus in Drosophila melanogaster. A similar structure between insect ace gene has been found, with conserved exon-intron positions and junction sequences. The B. oleae ace locus extends for at least 75 kb, consists of ten exons with nine introns and is mapped to division 34 of the chromosome arm IIL. Moreover, according to bioinformatic analysis, the Bo AChE exhibits all the common features of the insect AChE. Such structural and functional similarity among closely related AChE enzymes may implicate similarities in insecticide resistance mechanisms.
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spinosad resistance development in wild Olive Fruit Fly bactrocera oleae diptera tephritidae populations in california
Pest Management Science, 2010Co-Authors: Evi G Kakani, Nicos Seraphides, Konstantina T. Tsoumani, Frank G Zalom, Nikos E Zygouridis, Kostas D. MathiopoulosAbstract:BACKGROUND: Among target pests of the insecticide spinosad is the Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae). In Cyprus, spinosad has been sporadically used since its registration in 2002, whereas in Greece its use has been very limited since its registration in 2004, particularly in biological Olive cultivars in Crete. By contrast, in California it has been the only insecticide used against the Olive Fruit Fly since its registration in 2004. This study aimed at examining the resistance status of the Olive Fruit Fly to spinosad. RESULTS: Populations from California, Greece and Cyprus, plus a laboratory population, were tested. Bioassays were performed by oral or topical application of different concentrations of the insecticide. Cypriot populations demonstrated no resistance as compared with that of the laboratory population. Among the Greek populations, only one from Crete demonstrated a fourfold increase in resistance, whereas five populations from California demonstrated a 9–13-fold increase. CONCLUSION: The observed resistance increase was associated with spinosad applications in the respective areas. These values are relatively low and do not yet pose a serious control problem in the field. However, the observed variation documents that spinosad tolerance has increased in areas where the insecticide has been more extensively used. Copyright © 2010 Society of Chemical Industry
Polychronis Rempoulakis - One of the best experts on this subject based on the ideXlab platform.
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one for all mating compatibility among various populations of Olive Fruit Fly diptera tephritidae for application of the sterile insect technique
PLOS ONE, 2018Co-Authors: Sohel Ahmad, Carlos Caceres, Ihsan Ul Haq, Ulysses Sto Tomas, Thilakasiri Dammalage, Keke Gembinsky, Hannes F Paulus, Marc J B Vreysen, Polychronis RempoulakisAbstract:The Olive Fruit Fly, Bactrocera oleae (Rossi), is the most important insect pest for the cultivation of Olives worldwide. Considerable research efforts have been invested in the past decades to develop eradication or suppression tactics for use within an area-wide integrated pest management (AW-IPM) approach that includes a sterile insect technique (SIT) component. One of the major obstacles encountered in the development of SIT for Olive Fruit Fly was the inferior quality of the mass-reared flies, expressed among others evident primarily by sterile males having a different timing of peak mating and a lower mating propensity in comparison with their wild counterparts. In this study we assessed the mating behaviour and mating compatibility of Olive Fruit flies originating from four countries of the Mediterranean region (Croatia, France, Italy, Spain) in walk-in field cages and post zygotic compatibility (expressed as % egg hatch) under laboratory conditions. Furthermore, we tested the hypothesis whether a hybrid strain (Greece (domesticated)/Israel (wild)) adapted to laboratory rearing conditions showed any mating barriers with all the four “wild” populations. Finally, we examined the effect of colonization on the mating compatibility of the four newly established populations over three consecutive generations. The results showed no pre-zygotic (mating barriers) or post-zygotic isolations (measured by egg hatch%) among the Olive Fruit Fly populations from the four countries tested. Also, there was no evidence of mating barriers between the hybrid strain and the wild populations of the Mediterranean region.
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improving Olive Fruit Fly bactrocera oleae diptera tephritidae adult and larval artificial diets microflora associated with the Fly and evaluation of a transgenic Olive Fruit Fly strain
International Journal of Tropical Insect Science, 2014Co-Authors: Polychronis Rempoulakis, Ioannis Dimou, Antonios Chrysargyris, Aris EconomopoulosAbstract:Research on the Olive Fruit Fly Bactrocera oleae (Rossi) - rearing simplification, insect microflora and transgenic strain evaluation - yielded several findings: (1) incorporation of antibiotics in the adult diet is evidently not needed; (2) colonization appears to be easier when wild adults are collected from the field instead of using mature larvae emerging from field-collected infested Olives; (3) a combination of standard solid starter with liquid (no cellulose powder) finisher impregnated in synthetic sponge larval diets was more promising compared with all-liquid diets; (4) molecular analysis revealed extensive differences in bacterial species associated with the Fly between laboratory flies and strains from different Olive varieties, as well as between strains originating from different seasons of the year; (5) when an enhanced green fluorescent protein transgenic strain was compared with the standard long mass-reared strain, it proved significantly inferior according to all quality control tests applied, i.e. egg production, egg hatch, larval-stage duration, pupal recovery, pupal weight, adult emergence and adult survival. The aforementioned findings are discussed in the context of mass rearing and quality requirements for more successful implementation of the sterile insect technique against this pest.
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control of the Olive Fruit Fly using genetics enhanced sterile insect technique
BMC Biology, 2012Co-Authors: Martha Koukidou, John Vontas, Polychronis Rempoulakis, Aris Economopoulos, Hong Fei Gong, Luke AlpheyAbstract:Background The Olive Fruit Fly, Bactrocera oleae, is the major arthropod pest of commercial Olive production, causing extensive damage to Olive crops worldwide. Current control techniques rely on spraying of chemical insecticides. The sterile insect technique (SIT) presents an alternative, environmentally friendly and species-specific method of population control. Although SIT has been very successful against other tephritid pests, previous SIT trials on Olive Fly have produced disappointing results. Key problems included altered diurnal mating rhythms of the laboratory-reared insects, resulting in asynchronous mating activity between the wild and released sterile populations, and low competitiveness of the radiation-sterilised mass-reared flies. Consequently, the production of competitive, male-only release cohorts is considered an essential prerequisite for successful Olive Fly SIT.
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prevalence of candidatus erwinia dacicola in wild and laboratory Olive Fruit Fly populations and across developmental stages
Environmental Entomology, 2012Co-Authors: Anne M Estes, Polychronis Rempoulakis, Hannah J Burrack, David J Hearn, Elizabeth A PiersonAbstract:ABSTRACT The microbiome of the Olive Fruit Fly, Bactrocera oleae (Gmelin), a worldwide pest of Olives (Olea europaea L.), has been examined for >100 yr as part of efforts to identify bacteria that are plant pathogens vectored by the Fly or are beneficial endosymbionts essential for the Fly's survival and thus targets for possible biological control. Because tephritid Fruit flies feed on free-living bacteria in their environment, distinguishing between the transient, acquired bacteria of their diet and persistent, resident bacteria that are vertically transmitted endosymbionts is difficult. Several culture-dependent and -independent studies have identified a diversity of species in the Olive Fruit Fly microbiome, but they have not distinguished the roles of the microbes. Candidatus Erwinia dacicola, has been proposed to be a coevolved endosymbiont of the Olive Fruit Fly; however, this was based on limited samples from two Italian populations. Our study shows that C. Erwinia dacicola was present in all New ...
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Olive Fruit Fly bactrocera dacus oleae rossi diptera tephritidae adult rearing diet without antibiotic
Journal of Applied Entomology, 2010Co-Authors: Ioannis Dimou, Polychronis Rempoulakis, Aris EconomopoulosAbstract:The Olive Fruit Fly [Bactrocera (Dacus) oleae (Rossi) (Diptera: Tephritidae)] adult diet since its development in the 1960’s regularly incorporates antibiotic. Considering recent findings on the importance and function of the indigenous microbial flora of insects, the effects of antibiotic removal were measured on the survival and egg laying of wild flies derived from McPhail trappings and from field infested Olive Fruits. In the first case wild flies fed no antibiotic laid significantly greater numbers of eggs for two generations (in 5 out of 10 and 2 out of 10 counting dates for G1 and G2 respectively), while there were no significant differences in survival in either test (P = 0.221 for P generation, P = 0.988 for G1 generation from McPhail traps, P = 0.056 for flies from infested Fruits). Percent egg‐pupa recovery and adult emergence were not significantly affected by lack of antibiotic. An antibiotic-free strain has been maintained for eight generations, showing acceptable performance when compared to the long-reared standard ‘Laboratory’ strain. Overall results suggest the feasibility of an adult diet free of antibiotic without negative effects on colony survival and performance. J. Appl. Entomol.
Evi G Kakani - One of the best experts on this subject based on the ideXlab platform.
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decoding the reproductive system of the Olive Fruit Fly bactrocera oleae
Genes, 2021Co-Authors: Mariaeleni Gregoriou, Konstantina T. Tsoumani, Evi G Kakani, Martin Reczko, Kostas D. MathiopoulosAbstract:In most diploid organisms, mating is a prerequisite for reproduction and, thus, critical to the maintenance of their population and the perpetuation of the species. Besides the importance of understanding the fundamentals of reproduction, targeting the reproductive success of a pest insect is also a promising method for its control, as a possible manipulation of the reproductive system could affect its destructive activity. Here, we used an integrated approach for the elucidation of the reproductive system and mating procedures of the Olive Fruit Fly, Bactrocera oleae. Initially, we performed a RNAseq analysis in reproductive tissues of virgin and mated insects. A comparison of the transcriptomes resulted in the identification of genes that are differentially expressed after mating. Functional annotation of the genes showed an alteration in the metabolic, catalytic, and cellular processes after mating. Moreover, a functional analysis through RNAi silencing of two differentially expressed genes, yellow-g and troponin C, resulted in a significantly reduced oviposition rate. This study provided a foundation for future investigations into the Olive Fruit Fly’s reproductive biology to the development of new exploitable tools for its control.
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detection and geographical distribution of the organophosphate resistance associated δ3q ace mutation in the Olive Fruit Fly bactrocera oleae rossi
Pest Management Science, 2014Co-Authors: Evi G Kakani, Ioannis M. Ioannides, Efthymia Sagri, Michalis Omirou, Kostas D. MathiopoulosAbstract:BACKGROUND The Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), is the most important pest of Olives. Its control is based mostly on organophosphate (OP) insecticides, a practice that has led to resistance development. OP resistance in B. oleae has been associated with three mutations in the acetylcholinesterase (AChE), the product of ace gene. The current study presents new diagnostic tests for the detection of the ace mutations and aims at monitoring the frequency of the Δ3Q mutation, which appears associated with resistance at higher OP doses in natural Olive Fly populations. RESULTS An allele-specific polymerase chain reaction (PCR), a PCR-RFLP (restriction fragment length polymorphism) and a Taq-Man test were developed for the Δ3Q mutation detection and a new duplex quantitative PCR assay was designed for the G488S and I214V mutations. Moreover, the frequency of Δ3Q mutation was examined in ten populations of eight countries around the Mediterranean basin. The highest frequencies (10%) were found in Greece and Italy, whereas a gradual decrease of Δ3Q frequency towards the western Mediterranean was noted. CONCLUSION Robust tests for insecticide resistance mutations at their incipient levels are essential tools to monitor the increase and geographical spread of such mutations. Three different tests were developed for AChE-Δ3Q that indicated its association with OP applications across the Mediterranean. © 2013 Society of Chemical Industry
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Genomic structure, organization and localization of the acetylcholinesterase locus of the Olive Fruit Fly, Bactrocera oleae.
Bulletin of entomological research, 2012Co-Authors: Evi G Kakani, Elena Drosopoulou, Penelope Mavragani-tsipidou, M. Trakala, Kostas D. MathiopoulosAbstract:Acetylcholinesterase (AChE), encoded by the ace gene, is a key enzyme of cholinergic neurotransmission. Insensitive acetylcholinesterase (AChE) has been shown to be responsible for resistance to OPs and CBs in a number of arthropod species, including the most important pest of Olives trees, the Olive Fruit Fly Bactrocera oleae. In this paper, the organization of the B. oleae ace locus, as well as the structural and functional features of the enzyme, are determined. The organization of the gene was deduced by comparison to the ace cDNA sequence of B. oleae and the organization of the locus in Drosophila melanogaster. A similar structure between insect ace gene has been found, with conserved exon-intron positions and junction sequences. The B. oleae ace locus extends for at least 75 kb, consists of ten exons with nine introns and is mapped to division 34 of the chromosome arm IIL. Moreover, according to bioinformatic analysis, the Bo AChE exhibits all the common features of the insect AChE. Such structural and functional similarity among closely related AChE enzymes may implicate similarities in insecticide resistance mechanisms.
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spinosad resistance development in wild Olive Fruit Fly bactrocera oleae diptera tephritidae populations in california
Pest Management Science, 2010Co-Authors: Evi G Kakani, Nicos Seraphides, Konstantina T. Tsoumani, Frank G Zalom, Nikos E Zygouridis, Kostas D. MathiopoulosAbstract:BACKGROUND: Among target pests of the insecticide spinosad is the Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae). In Cyprus, spinosad has been sporadically used since its registration in 2002, whereas in Greece its use has been very limited since its registration in 2004, particularly in biological Olive cultivars in Crete. By contrast, in California it has been the only insecticide used against the Olive Fruit Fly since its registration in 2004. This study aimed at examining the resistance status of the Olive Fruit Fly to spinosad. RESULTS: Populations from California, Greece and Cyprus, plus a laboratory population, were tested. Bioassays were performed by oral or topical application of different concentrations of the insecticide. Cypriot populations demonstrated no resistance as compared with that of the laboratory population. Among the Greek populations, only one from Crete demonstrated a fourfold increase in resistance, whereas five populations from California demonstrated a 9–13-fold increase. CONCLUSION: The observed resistance increase was associated with spinosad applications in the respective areas. These values are relatively low and do not yet pose a serious control problem in the field. However, the observed variation documents that spinosad tolerance has increased in areas where the insecticide has been more extensively used. Copyright © 2010 Society of Chemical Industry
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Organophosphate resistance in Olive Fruit Fly, Bactrocera oleae, populations in Greece and Cyprus.
Pest management science, 2006Co-Authors: Panagiotis J. Skouras, Kostas D. Mathiopoulos, John T. Margaritopoulos, Nicos Seraphides, Ioannis M. Ioannides, Evi G Kakani, J.a. TsitsipisAbstract:The Olive Fruit Fly Bactrocera oleae (Gmelin) (Diptera: Tephritidae) is the most important pest of Olives in countries around the Mediterranean basin. Its control has been based mostly on bait sprays with organophosphate insecticides (usually dimethoate or fenthion) for about 40 years. In the present study, the resistance status of Olive Fruit Fly populations to dimethoate was examined in Greece and Cyprus over 2 years. Thirty-one populations from various regions of Greece, nine from Cyprus and one laboratory susceptible strain, which served as a control, were assayed by topical application of dimethoate. Considerable variation in the resistance levels to dimethoate was recorded in the populations of B. oleae, with resistance ratios ranging from 6.3 to 64.4 (ED50 values 12.5–128.7 ng dimethoate per insect). The highest resistance ratios were found in populations from Crete, and the lowest in those from Cyprus. This variation could be attributed to different selection pressures from insecticidal applications among populations from the various regions. Migration of resistant genotypes, either autonomous or via commerce, may also be involved. Copyright © 2006 Society of Chemical Industry
