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Phillip W. Taylor - One of the best experts on this subject based on the ideXlab platform.
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Disruption of duplicated yellow genes in Bactrocera tryoni modifies pigmentation colouration and impacts behaviour
Journal of Pest Science, 2020Co-Authors: Thu N. M. Nguyen, Phillip W. Taylor, Vivian Mendez, Amanda Choo, Peter Crisp, Christopher Ward, Alexie Papanicolaou, Simon W. BaxterAbstract:Irradiated Queensland fruit flies ( Bactrocera tryoni ) used in Sterile Insect Technique (SIT) programmes are marked with fluorescent dyes to distinguish them from wild flies when recaptured in monitoring traps. However, coating sterile pupae with powdered dyes can reduce emergence rates and fly quality and can sometimes produce insufficiently certain discrimination through inadequate coating or because the dye is transferred to wild flies through contact. Here we created a phenotypically distinct B. tryoni strain that lacks typical melanisation patterns through CRISPR/Cas9-mediated mutagenesis of tandemly duplicated yellow-y genes and then assessed effects of this visible trait on fly performance. Recessive mutations are only required in one of these copies to restrict melanisation and generate a phenotype clearly distinguished from wild type. The yellow strain showed significant declines in eclosion rates and in the percentage of fliers directly after emergence. Locomotor activity was greater in the yellow strain, and these mutations did not generally affect mating probability, copula latency, or copula duration. The longevity of yellow flies was approximately 10 days shorter than wild-type flies in both sexes. Overall, replacing dyes with yellow body marker for SIT can simplify production, eliminate a step that is known to reduce fly quality, remove potentially hazardous dyes from production, enable accurate discrimination from wild flies, and improve cost-effectiveness; however, direct comparisons of the decrements in performance associated with dyes on mass-reared wild-type flies and disruption of yellow-y genes are now required to determine the relative suitability of these marking methods for B. tryoni SIT.
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Cuticular Chemistry of the Queensland Fruit Fly Bactrocera tryoni (Froggatt)
Molecules (Basel Switzerland), 2020Co-Authors: Soo J. Park, Phillip W. Taylor, Gunjan Pandey, Cynthia Castro-vargas, John G. Oakeshott, Vivian MendezAbstract:The cuticular layer of the insect exoskeleton contains diverse compounds that serve important biological functions, including the maintenance of homeostasis by protecting against water loss, protection from injury, pathogens and insecticides, and communication. Bactrocera tryoni (Froggatt) is the most destructive pest of fruit production in Australia, yet there are no published accounts of this species’ cuticular chemistry. We here provide a comprehensive description of B. tryoni cuticular chemistry. We used gas chromatography-mass spectrometry to identify and characterize compounds in hexane extracts of B. tryoni adults reared from larvae in naturally infested fruits. The compounds found included spiroacetals, aliphatic amides, saturated/unsaturated and methyl branched C12 to C20 chain esters and C29 to C33 normal and methyl-branched alkanes. The spiroacetals and esters were found to be specific to mature females, while the amides were found in both sexes. Normal and methyl-branched alkanes were qualitatively the same in all age and sex groups but some of the alkanes differed in amounts (as estimated from internal standard-normalized peak areas) between mature males and females, as well as between mature and immature flies. This study provides essential foundations for studies investigating the functions of cuticular chemistry in this economically important species.
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commensal microbiota modulates larval foraging behaviour development rate and pupal production in Bactrocera tryoni
BMC Microbiology, 2019Co-Authors: Phillip W. Taylor, Fleur Ponton, Juliano Morimoto, Binh Nguyen, Shabnam T. Tabrizi, Ida Lundbäck, Toni A. ChapmanAbstract:Commensal microbes can promote survival and growth of developing insects, and have important fitness implications in adulthood. Insect larvae can acquire commensal microbes through two main routes: by vertical acquisition from maternal deposition of microbes on the eggshells and by horizontal acquisition from the environment where the larvae develop. To date, however, little is known about how microbes acquired through these different routes interact to shape insect development. In the present study, we investigated how vertically and horizontally acquired microbiota influence larval foraging behaviour, development time to pupation and pupal production in the Queensland fruit fly (‘Qfly’), Bactrocera tryoni. Both vertically and horizontally acquired microbiota were required to maximise pupal production in Qfly. Moreover, larvae exposed to both vertically and horizontally acquired microbiota pupated sooner than those exposed to no microbiota, or only to horizontally acquired microbiota. Larval foraging behaviour was also influenced by both vertically and horizontally acquired microbiota. Larvae from treatments exposed to neither vertically nor horizontally acquired microbiota spent more time overall on foraging patches than did larvae of other treatments, and most notably had greater preference for diets with extreme protein or sugar compositions. The integrity of the microbiota early in life is important for larval foraging behaviour, development time to pupation, and pupal production in Qflies. These findings highlight the complexity of microbial relations in this species, and provide insights to the importance of exposure to microbial communities during laboratory- or mass-rearing of tephritid fruit flies.
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Commensal microbiota modulates larval foraging behaviour, development rate and pupal production in Bactrocera tryoni
BMC Microbiology, 2019Co-Authors: Juliano Morimoto, Phillip W. Taylor, Fleur Ponton, Binh Nguyen, Shabnam T. Tabrizi, Ida Lundbäck, Toni A. ChapmanAbstract:Backround Commensal microbes can promote survival and growth of developing insects, and have important fitness implications in adulthood. Insect larvae can acquire commensal microbes through two main routes: by vertical acquisition from maternal deposition of microbes on the eggshells and by horizontal acquisition from the environment where the larvae develop. To date, however, little is known about how microbes acquired through these different routes interact to shape insect development. In the present study, we investigated how vertically and horizontally acquired microbiota influence larval foraging behaviour, development time to pupation and pupal production in the Queensland fruit fly (‘Qfly’), Bactrocera tryoni . Results Both vertically and horizontally acquired microbiota were required to maximise pupal production in Qfly. Moreover, larvae exposed to both vertically and horizontally acquired microbiota pupated sooner than those exposed to no microbiota, or only to horizontally acquired microbiota. Larval foraging behaviour was also influenced by both vertically and horizontally acquired microbiota. Larvae from treatments exposed to neither vertically nor horizontally acquired microbiota spent more time overall on foraging patches than did larvae of other treatments, and most notably had greater preference for diets with extreme protein or sugar compositions. Conclusion The integrity of the microbiota early in life is important for larval foraging behaviour, development time to pupation, and pupal production in Qflies. These findings highlight the complexity of microbial relations in this species, and provide insights to the importance of exposure to microbial communities during laboratory- or mass-rearing of tephritid fruit flies.
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High productivity gel diets for rearing of Queensland fruit fly, Bactrocera tryoni
Journal of Pest Science, 2016Co-Authors: Tahereh Moadeli, Phillip W. Taylor, Fleur PontonAbstract:The Queensland fruit fly or ‘Q-fly,’ Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), is Australia’s most damaging insect pest of horticulture. The sterile insect technique (SIT) is being developed as a sustainable approach to management of Q-fly. New larval diets are needed for economical production of millions of artificially reared sterile flies that are required for use in SIT. Solid diets that incorporate biological bulking agents present problems of variable quality and waste disposal. Liquid diets emerged as a promising alternative, but these also suffer drawbacks, including separation of components, fermentation and need for cleaning and regular replacement of substrates that support developing larvae. The present study considers whether two promising liquid diet formulations might be improved by incorporating agar (0, 0.25, 0.5, 1.0 and 1.5%) to create semiliquid or gel diets that maintain consistent composition, suppress fermentation, negate the need for supporting substrates and minimize waste. Overall, gel diets containing greater than 0.5% agar outperformed liquid diets (0% agar) and semiliquid diets (0.25% agar) of identical nutritional composition, especially in terms of development rate and productivity. Flies from the two tested diet formulations differed in flight performance, and this likely reflects differences in concentration of wheat germ oil and/or the type of yeast used. Overall, gel diets show great promise for rearing of Q-fly, overcoming many of the constraints of both traditional solid diets and more recently developed liquid diets. There is now a need for larger-scale trials that test and refine these diets for use in operational SIT settings.
Anthony R. Clarke - One of the best experts on this subject based on the ideXlab platform.
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Close‐distance courtship of laboratory reared Bactrocera tryoni (Diptera: Tephritidae)
Austral Entomology, 2018Co-Authors: Wasala M. T. D. Ekanayake, Anthony R. Clarke, Mark K. SchutzeAbstract:Close-range courtship behaviours are a critical element of a species’ biology but, if rapid, can often be overlooked. Beyond male chemical and audio calling, close-range courtship interactions leading to copulation in the Queensland fruit fly Bactrocera tryoni are unknown; this may be due to a true absence or because they have been overlooked and not previously investigated.We sought to resolve the close-range courtship sequence of B. tryoni and construct an ethogram of identified behaviours. Close-range video recordings of B. tryoni courtship were taken during the dusk mating window and an ethogram constructed by combining all observed behaviours which led to successful copulation and unsuccessful copulation. While the previously well-recognised male wing fanning behaviour was documented, a number of other behaviours were identified for the first time in B. tryoni courtship, including female ovipositor extension, and both male and female synchronous supination, face-to-face contact, and fore- and hind leg interactions. Analyses showed that the total duration of male synchronous supination, but not the number of occurrences, differed significantly between successful and unsuccessful males. Male foreleg interaction with the female abdomen was significantly different in both total duration and total number of occurrences between successful and unsuccessful males. The results reinforce data obtained from other Bactrocera species of simplified courtship sequences in these flies in comparison with other tephritid genera, but nevertheless courtship is more complex than previously recognised.
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Output DNA of 200–300 bp size (enriched product) obtained from a starting material of 10 ng of antibody conjugated DNA from Bactrocera tryoni head tissues using Illumina Truseq ChIP sample preparation kit.
2018Co-Authors: Kumaran Nagalingam, Anthony R. Clarke, Michał T. Lorenc, Sahana Manoli, Stephen L. Cameron, Kevin J. DudleyAbstract:Output DNA of 200–300 bp size (enriched product) obtained from a starting material of 10 ng of antibody conjugated DNA from Bactrocera tryoni head tissues using Illumina Truseq ChIP sample preparation kit.
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Effect of Body Size, Age, and Premating Experience on Male Mating Success in Bactrocera tryoni (Diptera: Tephritidae).
Journal of economic entomology, 2017Co-Authors: E W M T D Ekanayake, Anthony R. Clarke, Mark K. SchutzeAbstract:Variation in male body size, age, and prior sexual experience may all influence male mating success in tephritid fruit flies. Bactrocera tryoni (Froggatt) is an Australian pest tephritid for which the sterile insect technique (SIT) is being actively pursued, and for which information on what makes males more competitive is urgently needed. Pair-wise competitive mating trials were run using laboratory-reared flies in walk-in field cages, evaluating young, large, and virgin B. tryoni males against old, small, and nonvirgin males, respectively. Analysis of male sexual competitiveness indices revealed that young and large males obtained significantly more copulations compared to old and small males; there was no significant difference between virgin and nonvirgin males in obtaining mates. While SIT programs will always release young males, the results do show that rearing programs which focus on producing larger males, rather than greater numbers of smaller males, will produce more sexually competitive males. After release, virgin SIT males will not be at a competitive disadvantage with sexually experienced males based on prior mating experience.
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The mating system of the true fruit fly Bactrocera tryoni and its sister-species, Bactrocera neohumeralis.
Insect science, 2016Co-Authors: Wasala M. T. D. Ekanayake, Mudalige S. H. Jayasundara, Thelma Peek, Anthony R. Clarke, Mark K. SchutzeAbstract:The frugivorous "true" fruit fly, Bactrocera tryoni (Queensland fruit fly), is presumed to have a nonresourced-based lek mating system. This is largely untested, and contrary data exists to suggest Bactrocera tryoni may have a resource-based mating system focused on fruiting host plants. We tested the mating system of Bactrocera tryoni, and its close sibling Bactrocera neohumeralis, in large field cages using laboratory reared flies. We used observational experiments that allowed us to determine if: (i) mating pairs were aggregated or nonaggregated; (ii) mating system was resource or nonresource based; (iii) flies utilized possible landmarks (tall trees over short) as mate-rendezvous sites; and (iv) males called females from male-dominated leks. We recorded nearly 250 Bactrocera tryoni mating pairs across all experiments, revealing that: (i) mating pairs were aggregated; (ii) mating nearly always occurred in tall trees over short; (iii) mating was nonresource based; and (iv) that males and females arrived at the mate-rendezvous site together with no evidence that males preceded females. Bactrocera neohumeralis copulations were much more infrequent (only 30 mating pairs in total), but for those pairs there was a similar preference for tall trees and no evidence of a resource-based mating system. Some aspects of Bactrocera tryoni mating behavior align with theoretical expectations of a lekking system, but others do not. Until evidence for unequivocal female choice can be provided (as predicted under a true lek), the mating system of Bactrocera tryoni is best described as a nonresource based, aggregation system for which we also have evidence that land-marking may be involved.
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The mating system of the true fruit fly Bactrocera tryoni and its sister-species, Bactrocera neohumeralis
Science & Engineering Faculty, 2016Co-Authors: Wasala M. T. D. Ekanayake, Mudalige S. H. Jayasundara, Thelma Peek, Anthony R. Clarke, Mark K. SchutzeAbstract:The frugivorous 'true' fruit fly, Bactrocera tryoni (Queensland fruit fly), is presumed to have a non-resourced-based lek mating system. This is largely untested, and contrary data exists to suggest Bactrocera tryoni may have a resource-based mating system focused on fruiting host plants. We tested the mating system of Bactrocera tryoni, and its close sibling Bactrocera neohumeralis, in large field cages using laboratory reared flies. We used observational experiments that allowed us to determine if: - (i) mating pairs were aggregated or non-aggregated; - (ii) mating system was resource or non-resource based; - (iii) flies utilised possible landmarks (tall trees over short) as mate-rendezvous sites, and; - (iv) males called females from male-dominated leks. We recorded nearly 250 Bactrocera tryoni mating pairs across all experiments, revealing that: - (i) mating pairs were aggregated; - (ii) mating nearly always occurred in tall trees over short; - (iii) mating was non-resource based, and; - (iv) that males and females arrived at the mate-rendezvous site together with no evidence that males preceded females. Bactrocera neohumeralis copulations were much more infrequent (only 30 mating pairs in total), but for those pairs there was a similar preference for tall trees and no evidence of a resource-based mating system. Some aspects of Bactrocera tryoni mating behaviour align with theoretical expectations of a lekking system, but others do not. Until evidence for unequivocal female choice can be provided (as predicted under a true lek), the mating system of Bactrocera tryoni is best described as a non-resource based, aggregation system for which we also have evidence that land-marking may be involved. This article is protected by copyright. All rights reserved.
M Frommer - One of the best experts on this subject based on the ideXlab platform.
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Germ-line transformation of the Queensland fruit fly, Bactrocera tryoni, using a piggyBac vector in the presence of endogenous piggyBac elements
Genetica, 2010Co-Authors: K. A. Raphael, Deborah C.a Shearman, K. Streamer, Jennifer L. Morrow, Alfred M. Handler, M FrommerAbstract:We report the heritable germ-line transformation of the Queensland fruit fly, Bactrocera tryoni, using a piggyBac vector marked with either the fluorescent protein DsRed or EGFP. A transformation frequency of 5–10% was obtained. Inheritance of the transgenes has remained stable over more than 15 generations despite the presence of endogenous piggyBac sequences in the B. tryoni genome. The sequence of insertion sites shows the usual canonical pattern of piggyBac integraton into TTAA target sites. An investigation of endogenous piggyBac elements in the B. tryoni genome reveals the presence of sequences almost identical to those reported recently for the B. dorsalis complex of fruit flies and two noctuid moths, suggesting a common origin of piggyBac sequences in these species. The availability of transformation protocols for B. tryoni has the potential to deliver improvements in the performance of the Sterile Insect Technique for this pest species.
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Bactrocera tryoni and closely related pest tephritids--molecular analysis and prospects for transgenic control strategies.
Insect biochemistry and molecular biology, 2004Co-Authors: Kathryn A. Raphael, Steven Whyard, Deborah C.a Shearman, M FrommerAbstract:Bactrocera tryoni is a serious pest of horticulture in eastern Australia. Here we review molecular data relevant to pest status and development of a transformation system for this species. The development of transformation vectors for non-drosophilid insects has opened the door to the possibility of improving the sterile insect technique (SIT), by genetically engineering factory strains of pest insects to produce male-only broods. Transposition assays indicate that all five of the vectors currently used for transformation in non-drosophilid species have the potential to be useful as transformation vectors in B. tryoni. Evidence of cross mobilization of hobo by an endogenous Homer element emphasises the necessity to understand the endogenous transposons within a species. The sex-specific doublesex and yolk protein genes have been characterized with a view to engineering a female-specific lethal gene or modifying gene expression through RNA interference (RNAi). Data are presented which indicate the potential of RNAi to modify the sex ratio of resultant broods. An understanding of how pest status is determined and maintained is being addressed through the characterization of genes of the circadian clock that enable the fly to adapt to environmental cues. Such an understanding will be useful in the future to the effective delivery of sophisticated pest control measures.
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Genetic and Molecular Markers of the Queensland Fruit Fly, Bactrocera tryoni
The Journal of heredity, 2003Co-Authors: Jing Ting Zhao, M Frommer, J A Sved, C B GilliesAbstract:Twenty-six microsatellite markers, along with two restriction fragment length polymorphism (RFLP) markers and three morphological markers, have been mapped to five linkage groups, corresponding to the five autosomes of the Queensland fruit fly, Bactrocera tryoni. All these molecular and genetic markers were genotyped in three-generation pedigrees. Eight molecular markers were also localized to the salivary gland polytene chromosomes by in situ hybridization. This provides a substantial starting point for an integrated genetic and physical map of B. tryoni.
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The scarlet eye colour gene of the tephritid fruit fly: Bactrocera tryoni and the nature of two eye colour mutations.
Insect molecular biology, 2003Co-Authors: J. T. Zhao, M Frommer, Craig L. Bennett, G. J. Stewart, K. A. RaphaelAbstract:A homologue of the Drosophila melanogaster eye-colour gene, scarlet (st), has been isolated from the genome of the tephritid fruit fly, Bactrocera tryoni. The comparison of the B. tryoni and D. melanogaster scarlet gene shows 71.2% and 79.3% sequence identity at the DNA and the derived amino acid level, respectively. Two allelic eye-colour mutations of B. tryoni, orange-eyes and lemon-eyes, have been recovered and found to be colocalized with the st gene. The st gene sequence in the two mutant strains has been examined for DNA sequence changes and expression levels.
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The genome of the Queensland fruit fly Bactrocera tryoni contains multiple representatives of the mariner family of transposable elements.
Insect molecular biology, 2001Co-Authors: C. L. Green, M FrommerAbstract:Representatives of five distinct types of transposable elements of the mariner family were detected in the genomes of the Queensland fruit fly Bactrocera tryoni and its sibling species Bactrocera neohumeralis by phylogenetic analysis of transposase gene fragments. Three mariner types were also found in an additional tephritid, Bactrocera jarvisi. Using genomic library screening and inverse PCR, full-length elements representing the mellifera subfamily (B. tryoni.mar1) and the irritans subfamily (B. tryoni.mar2) were isolated from the B. tryoni genome. Nucleotide consensus sequences for each type were derived from multiple defective copies. Predicted transposase sequences share approximately 23% amino acid identity. B. tryoni.mar1 elements have an estimated copy number of about 900 in the B. tryoni genome, whereas B. tryoni.mar2 element types appear to be present in low copy number.
Olivia Louise Reynolds - One of the best experts on this subject based on the ideXlab platform.
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A walk on the wild side: gut bacteria fed to mass-reared larvae of Queensland fruit fly [Bactrocera tryoni (Froggatt)] influence development
BMC Biotechnology, 2019Co-Authors: Lucas Alexander Shuttleworth, Mohammed Abul Monjur Khan, Damian Collins, Terrence Osborne, Mukesh Srivastava, Olivia Louise ReynoldsAbstract:Abstract Background The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera, Tephritidae) is the most significant insect pest of Australian horticulture. Bactrocera tryoni is controlled using a range of tools including the Sterile Insect Technique (SIT). Mass-rearing and irradiation of pupae in SIT can reduce the fitness and quality of the released sterile insects. Studies have also showed reduced microbial gut diversity in domesticated versus wild tephritids. Results Transmission electron microscopy confirmed the presence of the bacterial isolates in the mid-gut of mass-reared larvae, and plate counts from individual larval guts showed increased numbers of bacteria in supplemented larvae. Several developmental and fitness parameters were tested including larval development time (egg-hatch to pupation), pupal weight, emergence, flight ability, sex-ratio, and time to adult eclosion (egg-hatch to adult eclosion). Enterobacter sp. and Asaia sp. shortened larval development time, while this was delayed by Lactobacillus sp., Leuconostoc sp. and a blend of all four bacteria. The mean time from egg hatch to adult eclosion was significantly reduced by Leuconostoc sp. and the blend for males and females, indicating that the individual bacterium and consortium affect flies differently depending on the life stage (larval or pupal). There was no impact of bacterial supplemented larvae on pupal weight, emergence, flight ability, or sex ratio. Conclusions Our findings show that bacteria fed to the larval stage of B. tryoni can impart fitness advantages, but the selection of probiotic strains (individual or a consortium) is key, as each have varying effects on the host. Bacteria added to the larval diet particularly Leuconostoc sp. and the blend have the capacity to reduce costs and increase the number of flies produced in mass-rearing facilities by reducing time to adult eclosion by 1.3 and 0.8 mean days for males, and 1.2 and 0.8 mean days for females.
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A walk on the wild side: gut bacteria fed to mass-reared larvae of Queensland fruit fly [Bactrocera tryoni (Froggatt)] influence development.
BMC biotechnology, 2019Co-Authors: Lucas Alexander Shuttleworth, Mohammed Abul Monjur Khan, Damian Collins, Terrence Osborne, Mukesh Srivastava, Olivia Louise ReynoldsAbstract:The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera, Tephritidae) is the most significant insect pest of Australian horticulture. Bactrocera tryoni is controlled using a range of tools including the Sterile Insect Technique (SIT). Mass-rearing and irradiation of pupae in SIT can reduce the fitness and quality of the released sterile insects. Studies have also showed reduced microbial gut diversity in domesticated versus wild tephritids. Transmission electron microscopy confirmed the presence of the bacterial isolates in the mid-gut of mass-reared larvae, and plate counts from individual larval guts showed increased numbers of bacteria in supplemented larvae. Several developmental and fitness parameters were tested including larval development time (egg-hatch to pupation), pupal weight, emergence, flight ability, sex-ratio, and time to adult eclosion (egg-hatch to adult eclosion). Enterobacter sp. and Asaia sp. shortened larval development time, while this was delayed by Lactobacillus sp., Leuconostoc sp. and a blend of all four bacteria. The mean time from egg hatch to adult eclosion was significantly reduced by Leuconostoc sp. and the blend for males and females, indicating that the individual bacterium and consortium affect flies differently depending on the life stage (larval or pupal). There was no impact of bacterial supplemented larvae on pupal weight, emergence, flight ability, or sex ratio. Our findings show that bacteria fed to the larval stage of B. tryoni can impart fitness advantages, but the selection of probiotic strains (individual or a consortium) is key, as each have varying effects on the host. Bacteria added to the larval diet particularly Leuconostoc sp. and the blend have the capacity to reduce costs and increase the number of flies produced in mass-rearing facilities by reducing time to adult eclosion by 1.3 and 0.8 mean days for males, and 1.2 and 0.8 mean days for females.
A Meats - One of the best experts on this subject based on the ideXlab platform.
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genetic consequences of domestication and mass rearing of pest fruit fly Bactrocera tryoni diptera tephritidae
Journal of Economic Entomology, 2012Co-Authors: A S Gilchrist, Emilie Cameron, John A Sved, A MeatsAbstract:Tephritid fruit flies, an important pest of horticulture worldwide, are increasingly targeted for control or eradication by large-scale releases of sterile flies of the same species. For each species treated, strains must be domesticated for mass rearing to provide sufficiently large numbers of individuals for releases. Increases in productivity of domesticated tephritid strains are well documented, but there have been few systematic studies of the genetic consequences of domestication in tephritids. Here, we used nine DNA microsatellite markers to monitor changes in genetic diversity during the early generations of domestication in replicated lines of the fruit fly Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). The observed changes in heterozygosity and allelic richness were compared with the expected changes in heterozygosity generated by a stochastic simulation including genetic drift but not selection. The results showed that repeatable genetic bottlenecks occur in the early generations and that selection occurs in the later generations. Furthermore, using the same simulation, we show that there is inadvertent selection for increased productivity for the entire life on a mass-rearing colony, in addition to intentional selection for increased productivity. That additional selection results from the common practice of establishing the next generation of the breeding colony from a small proportion of one day's pupae collection (the pupal raffle). That selection occurs during all generations and acts only on fecundity variation. Practical methods to counter that unavoidable loss of genetic diversity during the domestication process in B. tryoni are discussed.
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Bacteria as food had no effect on fecundity during domestication of the fruit fly, Bactrocera tryoni
Journal of Applied Entomology, 2009Co-Authors: A Meats, K. Streamer, A S GilchristAbstract:Adult Bactrocera tryoni from different generations of domestication were given various diets to determine whether either or both the bacteria Klebsiella oxytoca and Klebsiella pneumoniae could provide a source of proteinaceous material sufficient to allow the female flies to produce mature oocytes and eggs or alternatively, whether the bacteria could act as a beneficial supplementary food when given in addition to the usual laboratory proteinaceous food that consisted of a paste of sucrose and yeast autolysate. Overall, there was no evidence from any generation studied that female flies could produce eggs or mature oocytes on a bacterial diet above the levels attained with access to culture medium without bacteria. Similarly, there was no evidence that bacterial supplementation to a diet that included a paste of sucrose and yeast autolysate was more beneficial than when the paste was the sole source of proteinaceous food. There was an increase in mature oocytes per female with the number of generations of culture but the extent of increase was greater when sugar/yeast paste was included in the diet. There was no evidence that mixtures of either bacterium species in nutrient broth or the broth itself was attractive to female B. tryoni over a distance of a few centimetres when the tested flies were caged at low density but flies of later generations did feed when offered either type of food at very close range.
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Behavioural responses of female Queensland fruit fly, Bactrocera tryoni, to mineral oil deposits
Entomologia Experimentalis et Applicata, 2007Co-Authors: Van Liem Nguyen, A Meats, George A Beattie, Robert Spooner-hart, Z. M Liu, Laura JiangAbstract:Behavioural responses of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), females to fruit dipped in water and fruit dipped in 0.5% (vol/vol) aqueous emulsions of a mineral oil were determined and analysed. The mineral oil was an n C20 ‐22 distillation fraction of the base oil used to produce an n C23 horticultural mineral oil. Females caged with oil-treated fruit had significantly longer prelanding intervals than females caged with water-dipped fruit. The latter was attacked immediately or shortly after being caged with flies whereas some oil-dipped fruit was not attacked within 180 min. The percentage of landings that led to oviposition on water- and oil-treated fruit were 58 and 13%, respectively, and the percentages ovipositing after probing were 74 and 25%, respectively. Likewise, average times spent probing were 7 vs. 31 s whereas average times spent ovipositing were 321 vs. 223 s. Females spent less than half as much time on oil-treated fruit than on water-treated fruit. Transition probabilities of rejection, when applied to the behaviour sequence indicated that oil-treated fruits are about nine times less likely to be infested with B. tryoni .
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The likely fate of hybrids of Bactrocera tryoni and Bactrocera neohumeralis.
Heredity, 2003Co-Authors: N Pike, William Y.s. Wang, A MeatsAbstract:Bactrocera tryoni (Froggatt) and B. neohumeralis (Hardy) (Diptera: Tephritidae) are sympatric species which hybridise readily in the laboratory yet remain distinct in the field. B. tryoni mates only at dusk and B. neohumeralis mates only during the day, but hybrids can mate at both times. We investigated the inheritance of mating time in successively backcrossed hybrid stocks to establish whether mating with either species is more likely. The progeny of all backcrosses to B. tryoni mated only at dusk. The majority of the progeny of the first and a minority of the progeny of the second backcross to B. neohumeralis also mated at dusk, but the third successive B. neohumeralis backcross produced flies that mated only during the day. This trend towards dominance of the B. tryoni trait was also reflected in a diagnostic morphological character. We discuss the possible genetic background for these phenomena and propose that unidirectional gene flow might explain how the two species remain distinct in the face of natural hybridisation.
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Potential for mating between Bactrocera tryoni (Froggatt) and Bactrocera neohumeralis (Hardy) (Diptera: Tephritidae)
Australian Journal of Entomology, 2002Co-Authors: Nathan Pike, A MeatsAbstract:We conducted a series of mating experiments in the laboratory and in a glasshouse to examine male calling and the potential for mating between Bactrocera tryoni and B. neohumeralis. Males of each species do make presumed courtship calls, but at entirely discrete periods and regardless of the presence of other males or females. Despite this, assortative mating tests in the glasshouse demonstrated the potential for rare interspecific matings. When F1 hybrids were included in these assortative mating tests they commonly mated with B. neohumeralis during the middle of the day and with B. tryoni at dusk. Hybrids may facilitate bidirectional gene flow between these species.
