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1
Cameron, Emilie C. "Fruit Fly Pests of Northwestern Australia." University of Sydney, 2007. http://hdl.handle.net/2123/1711.
Full textAbstract:
Doctor of Philosophy(PhD),<br>Until recently, Northwestern Australia was thought to be relatively free of serious fruit fly pests. Although a noxious strain, present in Darwin since 1985, was widely believed to be an infestation of the Queensland fruit fly, Bactrocera tryoni, from the East coast, the fruit flies present outside this area were believed to be the benign endemic species, B. aquilonis. However, during the year 2000, infestations of fruit flies were discovered on major commercial crops in both Western Australia and the Northern Territory. It was not known whether these outbreaks were due to an invasion of the major pest species, Bactrocera tryoni, a change in the behaviour of B. aquilonis, or a hybridisation event between the two species. Finding the source of these outbreaks has been complicated by the fact that, since B. tryoni and B. aquilonis are virtually indistinguishable morphologically, it was not known which species are present in the region. Traditionally any tryoni complex fly caught in the Northwest was called B. aquilonis based solely on location. In order to get a good population profile of the region, an extensive trapping program was set up to include flies from urban areas, commercial crops and natural areas where the benign strain is thought to remain. Tests of genetic differentiation and clustering analyses revealed a high degree of homogeneity in the Northwest samples, suggesting that just one species is present in the region. The Northwest samples were genetically differentiated from the Queensland samples but only to a small degree (FST =0.0153). MtDNA sequencing results also showed a small degree of differentiation between these regions. A morphological study of wing shape indicated that there are some minor identifiable morphological differences between East coast and Northwest laboratory reared flies. This difference was greater than that seen between B. jarvisi populations across the same geographic range. The results suggest that the flies caught in the Northwest are a separate population of B. tryoni. Soon after pest flies were discovered in Darwin, a population became established in Alice Springs. This population had a low genetic diversity compared with Queensland and Darwin populations, and showed evidence of being heavily founded. In 2000, an outbreak was discovered in the nearby town of Ti Tree. Due to the geographic and genetic similarity of these populations, Alice Springs was determined to be the source of the Ti Tree outbreak. To investigate the founding of these populations, a program was developed to estimate the propagule size. Using a simulation method seven different statistics were tested for estimating the propagule size of an outbreak population. For outbreaks originating from populations with high genetic diversity, the number of alleles was a good estimator of propagule size. When, however, the genetic diversity of the source population was already reduced, allele frequency measures, particularly the likelihood of obtaining the outbreak population from the source population, gave more accurate estimates. Applying this information to the Alice Springs samples, it was estimated that just five flies were needed to found the major population in and around Alice Springs. For Ti Tree, the propagule size was estimated to be 27 flies (minimum 10). In 2000, a much larger outbreak occurred in the developing horticultural region of Kununurra in northern Western Australia. An important question for the management of the problem is whether there is an established fly population or the flies are reinvading each year. This population was found to have a large amount of gene flow from the Northern Territory. Within the Kununurra samples, one group of flies was genetically differentiated from all the other samples. This group came from a small geographic area on the periphery of Kununurra and appeared to be the result of an invasion into this area at the time when the population was building up following the dry season. A further threat to the Northwest horticultural regions comes from B. jarvisi. A recent increase in the host range of this species has lead to speculation that it may become a greater pest in Northwestern Australia. At the present time, protocols for the population monitoring and disinfestation of this species are not in place. Here it is shown that B. jarvisi eggs are more heat tolerant than B. tryoni eggs and that monitoring of B. jarvisi populations is possible using cue lure traps placed according to fruiting time and location of their favoured host, Planchonia careya.
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Cameron, Emilie C. "Fruit Fly Pests of Northwestern Australia." Thesis, The University of Sydney, 2006. http://hdl.handle.net/2123/1711.
Full textAbstract:
Until recently, Northwestern Australia was thought to be relatively free of serious fruit fly pests. Although a noxious strain, present in Darwin since 1985, was widely believed to be an infestation of the Queensland fruit fly, Bactrocera tryoni, from the East coast, the fruit flies present outside this area were believed to be the benign endemic species, B. aquilonis. However, during the year 2000, infestations of fruit flies were discovered on major commercial crops in both Western Australia and the Northern Territory. It was not known whether these outbreaks were due to an invasion of the major pest species, Bactrocera tryoni, a change in the behaviour of B. aquilonis, or a hybridisation event between the two species. Finding the source of these outbreaks has been complicated by the fact that, since B. tryoni and B. aquilonis are virtually indistinguishable morphologically, it was not known which species are present in the region. Traditionally any tryoni complex fly caught in the Northwest was called B. aquilonis based solely on location. In order to get a good population profile of the region, an extensive trapping program was set up to include flies from urban areas, commercial crops and natural areas where the benign strain is thought to remain. Tests of genetic differentiation and clustering analyses revealed a high degree of homogeneity in the Northwest samples, suggesting that just one species is present in the region. The Northwest samples were genetically differentiated from the Queensland samples but only to a small degree (FST =0.0153). MtDNA sequencing results also showed a small degree of differentiation between these regions. A morphological study of wing shape indicated that there are some minor identifiable morphological differences between East coast and Northwest laboratory reared flies. This difference was greater than that seen between B. jarvisi populations across the same geographic range. The results suggest that the flies caught in the Northwest are a separate population of B. tryoni. Soon after pest flies were discovered in Darwin, a population became established in Alice Springs. This population had a low genetic diversity compared with Queensland and Darwin populations, and showed evidence of being heavily founded. In 2000, an outbreak was discovered in the nearby town of Ti Tree. Due to the geographic and genetic similarity of these populations, Alice Springs was determined to be the source of the Ti Tree outbreak. To investigate the founding of these populations, a program was developed to estimate the propagule size. Using a simulation method seven different statistics were tested for estimating the propagule size of an outbreak population. For outbreaks originating from populations with high genetic diversity, the number of alleles was a good estimator of propagule size. When, however, the genetic diversity of the source population was already reduced, allele frequency measures, particularly the likelihood of obtaining the outbreak population from the source population, gave more accurate estimates. Applying this information to the Alice Springs samples, it was estimated that just five flies were needed to found the major population in and around Alice Springs. For Ti Tree, the propagule size was estimated to be 27 flies (minimum 10). In 2000, a much larger outbreak occurred in the developing horticultural region of Kununurra in northern Western Australia. An important question for the management of the problem is whether there is an established fly population or the flies are reinvading each year. This population was found to have a large amount of gene flow from the Northern Territory. Within the Kununurra samples, one group of flies was genetically differentiated from all the other samples. This group came from a small geographic area on the periphery of Kununurra and appeared to be the result of an invasion into this area at the time when the population was building up following the dry season. A further threat to the Northwest horticultural regions comes from B. jarvisi. A recent increase in the host range of this species has lead to speculation that it may become a greater pest in Northwestern Australia. At the present time, protocols for the population monitoring and disinfestation of this species are not in place. Here it is shown that B. jarvisi eggs are more heat tolerant than B. tryoni eggs and that monitoring of B. jarvisi populations is possible using cue lure traps placed according to fruiting time and location of their favoured host, Planchonia careya.
3
Van, der Merwe Cornelia. "Longevity and oviposition of Mediterranean fruit fly (Ceratitis capitata) (Diptera : Tephritidae) fed on a predominantly sugar and a predominantly protein diet." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52326.
Full textAbstract:
Thesis (MSc)--University of Stellenbosch, 2001.<br>ENGLISH ABSTRACT: Experiments using the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), were conducted
to determine the mortality of males and females and the ovipositing ability of females fed on
two diets. The sugar diet consisted of 5: 1 sugar:protein and the protein diet consisted of 5:1
protein: sugar. Dilutions of 80%, 60%, 40%, 20% and 10% with water of both diets were also
provided to the flies. Female longevity was shorter than male longevity. There was no difference
in female longevity between fruit flies fed on the two diets. However, males fed on the sugar
diet lived longer than those fed on the protein diet. More eggs per female per day were laid by
those fed the sugar diet than by those fed the protein diet. There were no differences m
oviposition between flies fed on the different concentrations of the two diets.<br>AFRIKAANSE OPSOMMING: Proewe met die Mediterreense vrugtevlieg, Ceratitis capitata (Wiedemann), is uitgevoer om die
mortaliteit van die mannetjies en wyfies, asook eierlegging van wyfies wat met twee
verskillende diëte voorsien is, te bepaal. Die onderskeie diëte het uit 'n mengsel van proteïen en
suiker (5 dele suiker en 1 deel proteïen) en (5 dele proteïen en 1 deel suiker) bestaan.
Verdunnings van 80%, 60%, 40%, 20% en 10% is van die onderskeie diëte gemaak en aan die
vlieë voorsien. Daar was geen verskil in die lewensduur van wyfies wat op die twee diëte
gevoed is nie. Mannetjies wat op die oorwegende suiker dieët gevoed is, het langer as dié wat op
die proteïen dieët gevoed is, geleef. Vlieë wat op die suiker dieët gevoed het, het regdeur 'n hoër
gemiddelde daaglikse eierlegging per wyfie as dié wat op die proteïen dieët gevoed het, getoon.
Geen noemenswaardige verskil in eierlegging vir vlieë wat op verskillende konsentrasies van
die twee diëte gevoed het, is gevind nie.
4
Tasnin, Mst Shahrima. "Demographic structure and aging in Bactrocera tryoni (Diptera: Tephritidae) in subtropical Australia." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/207465/1/Mst%20Shahrima_Tasnin_Thesis.pdf.
Full textAbstract:
Queensland fruit fly is a destructive horticultural insect pest. Knowing the age-structure of fly populations, that is the relative proportion of young, middle-age, and old-age flies within a population at a given time, is critical for effective management. The thesis combined behavioural ecology with a novel mathematical analysis to identify the seasonal changes in the age of a wild Queensland fruit fly population. The study showed that the abundance and age-structure of the fly changed predictably with the season, strongly suggestive of an endogenous mechanism that helps the fly cope with seasonal changes in resource availability.
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Corcoran, R. J. "Fruit fly (Diptera:Tephritidae) responses to quarantine heat treatment /." St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16489.pdf.
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Wallace, Erin Louise. "Investigating Life History Stages and Methods to Interrupt the Life Cycle, and Suppress Offspring Production, in the Queensland Fruit Fly (Bactrocera tryoni)." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/365473.
Full textAbstract:
Outbreaks of insect pests pose a serious threat to local economies and global food production, with as much as 15% of global crop production lost to herbivorous insects annually. Outbreaks of transboundary pests and diseases that affect food crops have increased in frequency in conjunction with globalization, international trade and the impacts of climate change. Indeed, increasing global temperatures are predicted to increase the distribution, rate of development, survival and population density of many pest insects. Such changes have important ramifications for host plant exploitation.
The Queensland fruit fly (Bactrocera tryoni) is Australia’s worst horticultural pest, and is feared by international buyers of Australian produce. Like other Tephritid fruit fly species, B. tryoni has the potential to breach quarantine barriers via human mediated transport, and can rapidly establish in ‘new’ environments. This pest species is responsible for an estimated AU$28.5 million in annual yield loss, management costs and loss to domestic and international markets. Increasing and ongoing outbreaks of B. tryoni in Australia’s major growing regions has put international trade in jeopardy.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>Griffith School of Environment<br>Science, Environment, Engineering and Technology<br>Full Text
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Kölling, Nils. "Quantitative genetics of gene expression during fruit fly development." Thesis, University of Cambridge, 2016. https://www.repository.cam.ac.uk/handle/1810/256090.
Full textAbstract:
Over the last ten years, genome-wide association studies (GWAS) have been used to identify genetic variants associated with many diseases as well as quantitative phenotypes, by exploiting naturally occurring genetic variation in large cohorts of individuals. More recently, the GWAS approach has also been applied to highthroughput RNA sequencing (RNA-seq) data in order to find loci associated with different levels of gene expression, called expression quantitative trait loci (eQTL). Because of the large amount of data that is required for such high-resolution eQTL studies, most of them have so far been carried out in humans, where the cost of data collection could be justified by a possible future impact in human health. However, due to the rapidly falling price of high-throughput sequencing it is now also becoming feasible to perform high-resolution eQTL studies in higher model organisms. This enables the study of gene regulation in biological contexts that have so far been beyond our reach for practical or ethical reasons, such as early embryonic development. Taking advantage of these new possibilities, we performed a high-resolution eQTL study on 80 inbred fruit fly lines from the Drosophila Genetic Reference Panel, which represent naturally occurring genetic variation in a wild population of Drosophila melanogaster. Using a 3′ Tag RNA-sequencing protocol we were able to estimate the level of expression both of genes as well as of different 3′ isoforms of the same gene. We estimated these expression levels for each line at three different stages of embryonic development, allowing us to not only improve our understanding of D. melanogaster gene regulation in general, but also investigate how gene regulation changes during development. In this thesis, I describe the processing of 3′ Tag-Seq data into both 3′ isoform expression levels and overall gene expression levels. Using these expression levels I call proximal eQTLs both common and specific to a single developmental stage with a multivariate linear mixed model approach while accounting for various confounding factors. I then investigate the properties of these eQTLs, such as their location or the gene categories enriched or depleted in eQTLs. Finally, I extend the proximal eQTL calling approach to distal variants to find gene regulatory mechanisms acting in trans. Taken together, this thesis describes the design, challenges and results of performing a multivariate eQTL study in a higher model organism and provides new insights into gene regulation in D. melanogaster during embryonic development.
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Knowles-Barley, Seymour Francis. "Proteins, anatomy and networks of the fruit fly brain." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/6177.
Full textAbstract:
Our understanding of the complexity of the brain is limited by the data we can collect and analyze. Because of experimental limitations and a desire for greater detail, most investigations focus on just one aspect of the brain. For example, brain function can be studied at many levels of abstraction including, but not limited to, gene expression, protein interactions, anatomical regions, neuronal connectivity, synaptic plasticity, and the electrical activity of neurons. By focusing on each of these levels, neuroscience has built up a detailed picture of how the brain works, but each level is understood mostly in isolation from the others. It is likely that interaction between all these levels is just as important. Therefore, a key hypothesis is that functional units spanning multiple levels of biological organization exist in the brain. This project attempted to combine neuronal circuitry analysis with functional proteomics and anatomical regions of the brain to explore this hypothesis, and took an evolutionary view of the results obtained. During the process we had to solve a number of technical challenges as the tools to undertake this type of research did not exist. Two informatics challenges for this research were to develop ways to analyze neurobiological data, such as brain protein expression patterns, to extract useful information, and how to share and present this data in a way that is fast and easy for anyone to access. This project contributes towards a more wholistic understanding of the fruit fly brain in three ways. Firstly, a screen was conducted to record the expression of proteins in the brain of the fruit fly, Drosophila melanogaster. Protein expression patterns in the fruit fly brain were recorded from 535 protein trap lines using confocal microscopy. A total of 884 3D images were annotated and made available on an easy to use website database, BrainTrap, available at fruitfly.inf.ed.ac.uk/braintrap. The website allows 3D images of the protein expression to be viewed interactively in the web browser, and an ontology-based search tool allows users to search for protein expression patterns in specific areas of interest. Different expression patterns mapped to a common template can be viewed simultaneously in multiple colours. This data bridges the gap between anatomical and biomolecular levels of understanding. Secondly, protein trap expression patterns were used to investigate the properties of the fruit fly brain. Thousands of protein-protein interactions have been recorded by methods such as yeast two-hybrid, however many of these protein pairs do not express in the same regions of the fruit fly brain. Using 535 protein expression patterns it was possible to rule out 149 protein-protein interactions. Also, protein expression patterns registered against a common template brain were used to produce new anatomical breakdowns of the fruit fly brain. Clustering techniques were able to naturally segment brain regions based only on the protein expression data. This is just one example of how, by combining proteomics with anatomy, we were able to learn more about both levels of understanding. Results are analysed further in combination with networks such as genetic homology networks, and connectivity networks. We show how the wealth of biological and neuroscience data now available in public databases can be combined with the Brain- Trap data to reveal similarities between areas of the fruit fly and mammalian brain. The BrainTrap data also informs us on the process of evolution and we show that genes found in fruit fly, yeast and mouse are more likely to be generally expressed throughout the brain, whereas genes found only in fruit fly and mouse, but not yeast, are more likely to have a specific expression pattern in the fruit fly brain. Thus, by combining data from multiple sources we can gain further insight into the complexity of the brain. Neural connectivity data is also analyzed and a new technique for enhanced motifs is developed for the combined analysis of connectivity data with other information such as neuron type data and potentially protein expression data. Thirdly, I investigated techniques for imaging the protein trap lines at higher resolution using electron microscopy (EM) and developed new informatics techniques for the automated analysis of neural connectivity data collected from serial section transmission electron microscopy (ssTEM). Measurement of the connectivity between neurons requires high resolution imaging techniques, such as electron microscopy, and images produced by this method are currently annotated manually to produce very detailed maps of cell morphology and connectivity. This is an extremely time consuming process and the volume of tissue and number of neurons that can be reconstructed is severely limited by the annotation step. I developed a set of computer vision algorithms to improve the alignment between consecutive images, and to perform partial annotation automatically by detecting membrane, synapses and mitochondria present in the images. Accuracy of the automatic annotation was evaluated on a small dataset and 96% of membrane could be identified at the cost of 13% false positives. This research demonstrates that informatics technology can help us to automatically analyze biological images and bring together genetic, anatomical, and connectivity data in a meaningful way. This combination of multiple data sources reveals more detail about each individual level of understanding, and gives us a more wholistic view of the fruit fly brain.
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Ant, Thomas. "Genetic control of the olive fruit fly, Bactrocera oleae." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:43f97545-f631-43cc-991c-7edb6dd71d2d.
Full textAbstract:
The olive fruit fly, Bactrocera oleae, (Rossi) (Diptera:Tephritidae), is a key pest of olive crops. The sterile insect technique (SIT) is an environmentally benign and species-specific method of pest control, aiming to reduce the reproductive potential of a wild population through the mass-release of sterile insects. Previous olive fly SIT trials, involving the release of gamma-ray sterilised mixed-sex populations, achieved limited success. Key problems included altered diurnal mating rhythms of the laboratory-reared insects, leading to assortative mating between released and wild populations, and low competitiveness of the radiation sterilised mass-reared flies. Consequently, the production of competitive, male-only release cohorts is seen as essential. The RIDL (Release of Insects carrying a Dominant Lethal) system is a transgene-based derivative of SIT, one version of which involves the mass release of insects carrying a female specific lethal transgene (fsRIDL). This thesis describes: 1) the development of fsRIDL olive fly strains and the molecular analysis of transgene insertion and function; 2) the analysis of strain life-history parameters; 3) studies into sexual selection and mating compatibility; 4) a caged proof-of-principle population suppression trial; and, 5) selection dynamics on the fsRIDL trait in caged populations. Olive fly fsRIDL strains were developed with full female-lethal penetrance and repressibility. The lead strain displayed similar life-history and sexual competitiveness traits to those of the wild-type strain from which they were derived. In addition, transgenic males showed photoperiod compatibility and strong sexual competitiveness with field-collected wild olive flies. The feasibility of the fsRIDL approach was demonstrated when repeated male releases caused eradication of caged olive fly populations. Although needing field confirmation, these results suggest that fsRIDL olive fly strains may help to mitigate key problems experienced in previous olive fly SIT trials, and could help form the basis of a renewed effort towards olive fly SIT control.
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Wessendorf, Lisa H. V. "Genetic and molecular characterization of wing development in Drosophila." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309358.
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Marygold, Steven Jon. "Charaterization of genetic interactions between cell cycle regulators and Armadillo in Drosophila melanogaster." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368930.
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Reeve, Michael William. "Temperature, body size and life history in Drosophila melanogaster." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271338.
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Kim, Young Soo. "Behavioral studies of learning mechanism with three different subjects : Honey Bee, Fruit Fly, and Flesh Fly /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488193665236633.
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Friberg, Urban. "Sexual conflict and male-female coevolution in the fruit fly." Doctoral thesis, Umeå : Department of Ecology and Environmental Science, Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-735.
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Foda, M. E. M. "Chemical communication in the Mediterranean fruit fly Ceratitis capitata (Wiedemann)." Thesis, University of Southampton, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234432.
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Ruklisa, Dace. "Large scale genomic association studies in fruit fly and human." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610178.
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Weldon, Christopher W. "Dispersal and mating behaviour of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) : implications for population establishment and control /." Connect to full text, 2005. http://setis.library.usyd.edu.au/adt/public_html/adt-NU/public/adt-NU20051007.085638.
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Hoogwerf, A. M. "The genetics of a small autosomal region of Drosophila melanogaster, including the structural gene for larval serum protein two." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370260.
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Matheson, Alastair. "Teratology and the development of pattern in Drosophila." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293093.
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Chan, Adeline S. T. "Anastrepha ludens loew (Diptera: Tephritidae) : an integrated behavioural and ecological study." Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278494.
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Karunaratne, Swinitha. "Behaviour of the oriental fruit fly, Dacus dorsalis Hendel (Diptera: Tephritidae)." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293598.
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Ostrovsky, Aaron. "A sexually dimorphic olfactory circuit in the fruit fly, Drosophila melanogaster." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610165.
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Stainton, Kirsty. "Genetic control of the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae)." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670052.
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Irving, Andrew David. "General methods for large biological networks applied to fruit fly models." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/general-methods-for-large-biological-networks-applied-to-fruit-fly-models(5eb3812e-f2dc-488b-bba4-fa0f094d4776).html.
Full textAbstract:
A key part of a fruit fly's development is the formation of segmentsin its body. These structures are built by the protein forms of so-called segment polarity (SP) genes. It is the asymmetric expression of SP genes which creates the fruit-fly's segmental structure. The SP genes and their products (e.g. proteins) can be said to form a system which is self-regulating, i.e. genes are used to make proteins and, in turn, proteins are used to turn genes on or off. How this system achieves stable asymmetry of this kind is mathematically interesting as it can be thought of in a different way - multiple symmetries in the same system. This is unusual and we attempt to explain how it is possible using a mathematical model constructed by von Dassow et al. When trying to understand a biological system of this kind, there are two main approaches - reductionist and holistic. We try to show that they are not mutually exclusive - we look at the whole system but reduce what is meant by the whole. For example, von Dassow's model is large scale and, using it as a template, we show that a similar (but smaller) model inherits its properties. Smaller models can be made by short-handing the translation process (through which RNA is used to make protein) wherever an SP gene has a unique protein form. Our data indicates that the simultaneous wild-type expression of key SP genes (engrailed and wingless) takes place only when cumulative regulation of the wingless gene by two SP proteins is weak. The absence of this regulation would explain coexistence of multiple mathematical symmetries in one system (representative of genetic asymmetry) as it acts like a division between them. In this way, the system itself can be thought to divide into two independent sub-systems which can be treated separately.
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Duxbury, Elizabeth. "Sex, diet, health and lifespan in the fruit fly, Drosophila melanogaster." Thesis, University of East Anglia, 2017. https://ueaeprints.uea.ac.uk/63358/.
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Nutrition is a vital determinant of lifespan, reproduction, health and ageing. Much has been done to investigate the lifespan consequences of short-term (proximate) nutritional manipulation, but much less is known about long-term (evolutionary) nutritional manipulation and nutritional mismatches. In this thesis I addressed this important omission, using the fruit fly, Drosophila melanogaster, model system. I empirically tested two evolutionary theories: the Thrifty Phenotype and Thrifty Genotype hypotheses, which predict the general life history consequences of nutritional mismatches over the lifetime or over evolutionary time, respectively. I also tested how the latter interacted with long-term nutritional selection regimes. Contrary to predictions, I showed that the costs of nutritional mismatches between developmental and adult diets were not universal, but instead dependent on the nature of the mismatch, sex and the components of life history measured (Chapter 2). Similarly, the costs of mismatches between evolved and proximate nutrition were dependent on evolved feeding regime, sex, life history component measured and proximate diet (Chapter 3). I discovered that there was enhanced sexual dimorphism for lifespan in nutritionally selected lines, which was associated with sex-specific life history patterns and a partial resolution of sexual conflict (Chapter 4). Transcriptome-wide analysis of these nutritionally selected lines revealed differential expression in genes with functions related to lifespan, post-mating responses, regulation and epigenetic modification (Chapter 5). Finally, I found that manipulation of another important component of altered lifestyles, activity level, had no effect on lifespan or reproduction (Chapter 6). Overall, my results make a novel contribution to the study of nutritional mismatches and long-term nutritional selection. The results also highlight the importance of simultaneously studying both sexes and several age-specific components of life history, in different proximate environments, to fully elucidate the fitness consequences of nutritional manipulation.
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Goble, Tarryn Anne. "Investigation of entomopathogenic fungi for control of false codling moth, Thaumatotibia leucotrata, Mediterranean fruit fly, Ceratitis capitata and Natal fruit fly, C. rosa in South African citrus." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1005409.
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The biology of key citrus pests Thaumatotibia leucotreta Meyrick (Lepidoptera: Tortricidae), Ceratitis capitata Wiedemann (Diptera: Tephritidae) and Ceratitis rosa Karsch (Diptera: Tephritidae) includes their dropping from host plants to pupate in the soil below citrus trees. Since most EP fungi are soil-borne microorganisms, the development and formulation of alternative control strategies using these fungi as subterranean control agents, targeted at larvae and pupae in the soil, can potentially benefit existing IPM management of citrus in South Africa. Thus, a survey of occurrence of entomopathogenic fungi was undertaken on soils from citrus orchards and natural vegetation (refugia) on conventionally and organically managed farms in the Eastern Cape Province in South Africa. A method for baiting soil samples with citrus pest T. leucotreta and C. capitata larvae, as well as with the standard bait insect, Galleria mellonella Linnaeus (Lepidoptera: Pyralidae), was implemented. Sixty-two potentially useful entomopathogenic fungal isolates belonging to four genera were collected from 288 soil samples, an occurrence frequency of 21.53%. The most frequently isolated entomopathogenic fungal species was Beauveria bassiana (Balsamo) Vuillemin (15.63%), followed by Metarhizium anisopliae var. anisopliae (Metschnikoff) Sorokin (3.82%). Galleria mellonella was the most effective insect used to isolate fungal species (χ2=40.13, df=2, P≤ 0.005), with a total of 45 isolates obtained, followed by C. capitata with 11 isolates, and T. leucotreta with six isolates recovered. There was a significantly (χ2=11.65, df=1, P≤ 0.005) higher occurrence of entomopathogenic fungi in soil samples taken from refugia compared to cultivated orchards of both organically and conventionally managed farms. No significant differences were observed in the recovery of fungal isolates when soil samples from both farming systems were compared. The physiological effects and host range of 21 indigenous fungal isolates obtained in the Eastern Cape were investigated in the laboratory to establish whether these isolates could be effectively used as biological control agents against the subterranean life stages of C. rosa, C. capitata and T. leucotreta. When these pests were treated with a fungal concentration of 1 x 10⁷ conidia ml⁻¹, the percentage of T. leucotreta adults which emerged in fungal treated sand ranged from 5 to 60% (F=33.295; df=21; P=0.0001) depending on fungal isolate and the percentage of pupae with visible signs of mycosis ranged from 21 to 93% (F= 96.436; df=21; P=0.0001). Based on fungal isolates, the percentage adult survival in C. rosa and C. capitata ranged from 30 to 90% and 55 to 86% respectively. The percentage of C. rosa and C. capitata puparia with visible signs of mycosis ranged from 1 to 14% and 1 to 11% respectively. Deferred mortality due to mycosis in C. rosa and C. capitata adult flies ranged from 1 to 58% and 1 to 33% respectively, depending on fungal isolate. Entomopathogenic fungal isolates had a significantly greater effect on the adults of C. rosa and C. capitata than they did on the puparia of these two fruit fly species. Further, C. rosa and C. capitata did not differ significantly in their response to entomopathogenic fungi when adult survival or adult and pupal mycosis were considered. The relative potency of the four most virulent Beauveria isolates as well as the commercially available Beauveria bassiana product, Bb Plus® (Biological Control Products, South Africa), were compared against one another as log-probit regressions of mortality against C. rosa, C. capitata and T. leucotreta which all exhibited a dose-dependent response. Against fruit flies the estimated LC50 values of all five Beauveria isolates ranged from 5.5 x 10¹¹ to 2.8 x 10¹² conidia/ml⁻¹. There were no significant differences between the relative potencies of these five fungal isolates. When T. leucotreta was considered, isolates: G Moss R10 and G 14 2 B5 and Bb Plus® were significantly more pathogenic than G B Ar 23 B3 and FCM 10 13 L1. The estimated LC₅₀ values of the three most pathogenic isolates ranged from 6.8 x 10⁵ to 2.1 x 10⁶ conidia/ml⁻¹, while those of the least pathogenic ranged from 1.6 x 10⁷ to 3.7 x 10⁷ conidia/ml⁻¹. Thaumatotibia leucotreta final instar larvae were exposed to two conidial concentrations, at four different exposure times (12, 48, 72 and 96 hrs) and showed an exposure time-dependant relationship (F=5.43; df=3; P=0.001). At 1 x 10⁷conidia/ml⁻¹ two Beauveria isolates: G Moss R10 and G 14 2 B5 were able to elicit a response in 50% of test insects at 72 hrs (3 days) exposure. Although a limited amount of mycosis was observed in the puparia of both fruit fly species, deferred adult mortality due to mycosis was high. The increased incidence of adult mortality suggests that post emergence mycosis in adult fruit flies may play a more significant role in field suppression than the control of fruit flies at the pupal stage. The increased incidence of pupal mortality, as well as the relatively low concentrations of conidia required to elicit meaningful responses in T. leucotreta pupae may suggest that pre-emergent control of false codling moth will play a more significant role in field suppression than the control of adult life stages using indigenous isolates of entomopathogenic fungi. Various entomopathogenic fungal application techniques targeted at key insect pests within integrated pest management (IPM) systems of citrus are discussed.
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Arias, Mella Maria Belen. "Global and local population genetics of the Mediterranean fruit fly, Ceratitis capitata, an invasive pest of fruit crops." Thesis, Imperial College London, 2018. http://hdl.handle.net/10044/1/64776.
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Invasive species are recognised as one of the most important, growing threat to food biosecurity, causing a significant economic loss in agricultural systems. Despite their damaging effect, they are attractive models for the study of evolution and adaptation in newly colonised environments. Currently, the global climate represents one key potential stressors to impact the food biosecurity because of its influence in the distribution and change in the abundance of agricultural pests. The tephritid fruit flies (Diptera: Tephritidae) contain some of the most successful invaders and most devastating agricultural pests recognised worldwide. Among them, the Mediterranean fruit fly Ceratitis capitata and the South American fruit flies in the genus Anastrepha are particularly important for crop production. Insecticides have been used extensively for their control. This thesis investigates factors that are related to invasiveness in these species, in order to provide novel information that will ultimately improve management control methods. First, environmental niche modelling was used to determine the influence of climate change in the potential habitat distribution of C. capitata, predicting both polewards expansion as well as greater connectivity. Next, historical global dispersal patterns of the medfly over the past two centuries were investigated using molecular and genetic approaches. In Chapter 4, different attempts to identify the point mutation G328A Ccace2 gene that confers resistance to insecticides were assessed at local and intercontinental scale, in part by studying museum specimens from before and after the use of pesticides. Additionally, to improve genetic knowledge of this invasive species, the mitogenome of different species of Anastrepha were sequenced and analysed together with others tephritid. This investigation provides crucial information revealing the evolutionary factors that influence the medfly’s successful invasions and will contribute to the development of evidence-driven pest management protocols, especially in the Americas, including the choice among different control methods as well as the establishment of quarantine procedures to interrupt colonisation routes.
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Green, Darren Michael. "Coevolutionary dynamics in a parasitoid-host system." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312023.
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Rosewell, J. P. "Competition in multispecies systems : A theoretical and experimental study of the 'domestic' species of the genus Drosophila." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373474.
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Chadburn, R. G. "An investigation into the genetics and ecology of a closed semi-natural population of Drosophila melanogaster." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377122.
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Cripps, Richard Matthew. "Genetical and biochemical studies of Drosophila indirect flight muscles." Thesis, University of York, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276490.
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Enkerlin, Hoeflich Walther Raul. "Economic analysis of management for the Mediterranean fruit fly (Ceratitis capitata Wied.)." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268030.
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Hesketh, J. "Sex-specific selection and sexual antagonism in the fruit fly, Drosophila melanogaster." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1396235/.
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Males and females differ in their reproductive roles, and as a consequence each sex is subject to divergent selection pressures to optimise its own reproductive success. Due to the shared genome between males and females these selection pressures frequently act on shared phenotypic traits. Divergent selection can favour the invasion of sexually antagonistic alleles which increase the fitness of one sex at the detriment of the other. Sexual antagonism can be subsequently resolved through the evolution of sex-specific gene expression, allowing the sexes to diverge phenotypically. While sexual dimorphism is common, recent evidence shows that antagonistic genetic variation continues to segregate in populations of many organisms. The basis of sexual antagonism remains poorly understood. I first present empirical data on the interaction between sexual antagonism and genetic drift in small populations that had independently evolved under standardised conditions. I demonstrated that these experimental populations of Drosophila melanogaster had diverged in male and female fitness, with some populations showing increased male but decreased female fitness, while other populations showed the reverse pattern. I also exploited a sample of nine genomes that belonged to three fitness classes (low male/high female, high male/low female, intermediate in both sexes) to test the association between the sexually dimorphic trait wing morphology (size and shape) and fitness in both sexes. I found that wing morphology significantly affected the fitness of both males and females, but to a differing degree in each sex. In males wing shape rather than wing size was especially important. I found evidence that there was appropriate genetic architecture for the existence of sexual antagonism, and for divergent selection on aspects of wing morphology. I place all of my findings in the context of variation in sexually dimorphic traits and sex-specific fitness.
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Mahmood, Khalid. "Taxonomy of the fruit flies (Dacinae, Tephritidae, Diptera) of the Indo-Pak subcontinent and the oriental fruit fly complex." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300090.
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Marsden, Craig H. "The functional significance of fruit exocarp on host selection and oviposition by Queensland fruit fly, Bactrocera tryoni (Froggatt) (Tephritidae: Diptera)." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/76107/2/Craig_Marsden_Thesis.pdf.
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Queensland fruit fly is Australia's most serious insect pest of horticulture. The fly lays its eggs into fruit, where they hatch into maggots which destroy the fruit. Understanding egg laying behaviour, known as oviposition, is a critical but under-researched aspect of fruit fly biology. This thesis focused on three aspects of oviposition: the role of fruit peel as a physical barrier to oviposition; the quality of fruit for maggot development; and the structure and wear of the egg laying organ – the ovipositor. Results showed that flies selected fruit based on their suitability for offspring survival, not because of the softness or hardness of fruit peel. Previously reported use of holes or wounds in fruit peel by ovipositing females was determined to be a mechanism which saved the female time, not a mechanism to reduce ovipositor wear. The results offer insights into the evolution of host use by fruit flies and their sustainable management.
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Schuckel, Julia [Verfasser]. "Dynamic characterization of olfactory receptors in the fruit fly Drosophila melanogaster / Julia Schuckel." Kassel : Universitätsbibliothek Kassel, 2011. http://d-nb.info/101588198X/34.
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Mcclure, Colin. "Life history implications of sex, diet and pathogen exposure in the fruit fly." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633172.
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Understanding how organisms function is central to Biology. Assessing how animals respond to fluctuations in their environment and determining inter-individual variation in phenotypic plasticity is paramount to identifying the physiology of traits, the selective pressures which have shaped them, and how we can manipulate them to benefit human life. The over-arching goal of my thesis is to understand the effects of sex, diet and pathogen exposure on the physiology of the fruit fly to assess the versatility of their individual traits in response to these natural factors. Chapter 2 investigates how the sexes utilise nutrition towards their lifespan and reproduction, providing evidence that the reproduction of males and females requires different dietary components while lifespan does not. Chapter 3 reveals that the sexes also differ in how they utilise nutrients for pathogen resistance identifying that females are highly protein-limited and more susceptible to infection than males. Chapter 4 provides the first comprehensive study of how organisms alter their dietary intake in response to infection, finding that flies behaviourally ingest less and consume higher protein:carbohydrate ratio diets when exposed to live fungal spores. Chapter 5 explores the phenomenon of trait-enhnacing external stresses, a response often termed hormesis. This study reveals that the beneficial physiological response from inactive fungal spore exposure, a potential form of hormesis, incurs immune costs. The implications of my results to the field of physiology are discussed in Chapter 6 where I also highlight the limitations of my work and potential consequences for life history research. Overall it is determined that studies investigating the natural physiological response of organisms or potentially beneficial treatments for our own species, must consider sex-specific effects, physiological consequences in a variety of traits, and how organisms may utilise variation within their environment to alter their phenotypic condition.
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Leftwich, Philip. "Male reproductive success and population control in the Mediterranean fruit fly, Ceratitis capitata." Thesis, University of East Anglia, 2012. https://ueaeprints.uea.ac.uk/47288/.
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The traits that determine male reproductive success in Ceratitis capitata (medfly) are largely unknown. This comes despite decades of research into the reproductive behaviour of this agricultural pest. An understanding of what makes a successful male is of great importance in this lekking species, as one male has the ability to dominate access to females. In addition species-specific pest control techniques such as the Sterile Insect Technique (SIT) and Release of Insects carrying a Dominant Lethal (RIDL) rely on the mating competitiveness of mass-reared ‘sterile’ males to disrupt natural mating systems and reduce population numbers. However, it is well known that the mass-rearing process required to generate these individuals produces less competitive males, despite this an understanding of the sexual selection processes that are involved is severely lacking. In this thesis I used the medfly as a model organism to investigate the context-dependent nature of male reproductive success. In Chapters 2 and 3 I investigate the effect of manipulating the adult sex ratio on pre- and post-mating reproductive traits. Chapter 2 uses proximate manipulation of the adult sex ratio to show how the relationship between pre- and post-mating success is affected by the levels of male competition. Chapter 3 shows that selection lines are unable to select for the traits that predict male reproductive success under altered levels of male competition. Chapter 4 describes the attempts to produce RIDL genetic constructs with embryonic lethality. Chapter 5 demonstrates that RIDL lines of medfly display characteristics that make them suitable for wild population control and may exceed the performance of existing SIT lines. Chapter 6 shows that manipulation of the larval diet can alter the gut microbiota of adults; however these manipulations have no effect on reproductive behaviour. Instead there was a significant effect of high-sugar larval rearing on mating success and body mass. This effect persisted for a single generation in offspring of these flies, even when they were reared on an inferior starch-based larval diet. Finally Chapter 7 summarises the thesis and discusses the implications of this work and future directions for both research in the reproductive behaviour of the medfly, and the future of RIDL technology in medfly population control.
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Culwell, Thomas Franklin. "Study of the reproducibility of proteomics methods and variability of fruit fly proteomes /." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2252.pdf.
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Turney, Catherine Louise. "Transposable elements of the mariner family in the tephritid fruit fly, Bactrocera tryoni." Thesis, The University of Sydney, 1998. https://hdl.handle.net/2123/27649.
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The research outlined in this thesis primarily focused on the isolation and
characterization of representatives of the mariner family of transposable
elements in the genome of the tephritid, Bactrocera tryoni (Queensland
fruit fly). A preliminary investigation was also made of the mobility
properties of constructs based on the mariner element Mos], following
their transient introduction into the embryonic soma of B. tryoni. This
involved the use of plasmid-based excision and transposition assays. These
studies were partly undertaken to obtain an initial idea of the feasibility of
developing a germline transformation system based on particular mariner
elements for use with B. tryoni, and possibly other related tephritids.
To investigate whether the B. tryoni genome contained endogenous
mariner element copies, an initial PCR analysis was carried out using
degenerate oligonucleotide primers that had previously been designed to
stretches of conserved residues within transposases encoded by particular
mariner elements. Using this approach, examples of at least five distinct
types of mariner elements were detected in the genome of B. tryoni
following the cloning and DNA sequencing of 20 unique amplified
fragments. Phylogenetic analyses using the conceptual amino acid
translations of these partial transposase gene regions indicated that the B.
tryom‘ sequences represented three subfamilies of mariner elements. Using
the same PCR-based approach, diverse mariner sequences were also
isolated from Bactrocera neohumeralis, a sibling species of B. tryoni, and
an additional tephritid, Bactrocera jarvisi.
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Culwell, Thomas Franklin. "Study of the Reproducibility of Proteomics Methods and Variability of Fruit Fly Proteomes." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1232.
Full textAbstract:
The reliability of biomarker discovery by means of proteomics has been called into question. It was speculated that "background noise" variation resulting from differences in preparation and handling of samples and proteome dynamics may mask subtle, yet important, differences due to the biological condition. Little is understood about complex proteomes and their variability. A critical aspect of proteomic biomarker research that is largely unexplored is the comparative reproducibility of certain methods such as two-dimensional gel electrophoresis and liquid chromatography/mass spectrometry. In particular, with liquid chromatography/mass spectrometry, it is not known whether variability in peptide quantitation is dependent on any of their several properties such as size, abundance, or hydrophobicity. Such determinations may be critical in properly assessing the value of proteomics data. The fruit fly Drosophila melanogaster was used as a well-controlled multicellular animal model to study the relationship between the background variation and expected changes induced by environmental or genetic factors. The data, gathered by two different proteomics methods, were used to compare and evaluate the reproducibility of the methods. It is reported that there was on average 15 to 18% variability in quantitative measurements of protein abundance using 2-dimensional gel electrophoresis or liquid chromatography/mass spectrometry. Using liquid chromatography/mass spectrometry, peptides with a smaller mass-to-charge ratio were shown to be measured less reproducibly than peptides with a larger ratio. Statistically significant proteomic differences between fly populations could be demonstrated between males and females. In dynamic experiments, less than 0.5% of proteins measured were shown to change after 24 hour starvation of the flies. However, no significant difference in peptide composition could be found for flies fed on a second diet consisting of the standard diet augmented with 10% ethanol. These results suggest that proteomic variability while evident allowed for biomarker discovery using either method for this model system.
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Milligan, Colin D. "Transcripts from the head of Drosophila melanogaster." Thesis, University of Glasgow, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294171.
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Armstrong, James Douglas. "Structural characterisation of the Drosophila mushroom bodies." Thesis, University of Glasgow, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295342.
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Saaid, A. A. S. "Genetic and toxicological studies on the Mediterranian fruit fly Ceratitis capitata in relation to the development of a genetic sexing technique." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374778.
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Moy, F. H. "An experimental study of group selection using Drosphila melanogaster." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373127.
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Mahat, Kiran. "Effects on Attraction, Feeding and Mortality of Bactrocera tryoni (Froggatt) (Diptera:Tephritidae) and Beneficial Organisms with Protein Bait-Insecticide Mixtures." Thesis, Griffith University, 2009. http://hdl.handle.net/10072/367286.
Full textAbstract:
This thesis examines the effects of malathion, chlorpyrifos, fipronil and spinosad mixed in fruit fly protein bait on attraction, feeding and mortality of the Queensland fruit fly, Bactrocera tryoni (Froggatt). The effects of weathering of the protein bait-insecticide mixtures on the mortality of B. tryoni were also measured along with attraction, feeding response and toxicity of the protein bait sprays on important arthropod natural enemies particularly the red scale parasitic wasps, Aphytis lingnanensis (Compere) and Comperiella bifasciata (Howard), the green lace wing, Chrysoperla carnea (Stephens) and the mealy bug predator, Cryptolaemus montrouzieri (Mulsant).
In field cage experiments, protein-starved male B. tryoni showed the same level of attraction to protein baits mixed with malathion, chlorpyrifos, fipronil, spinosad and protein alone used as the control. However, protein-starved females elicited a difference in attraction with protein baits containing chlorpyrifos and spinosad. Traps with spinosad bait mixtures captured significantly more females compared to traps containing chlorpyrifos bait mixtures. Laboratory feeding experiments on protein-starved female flies demonstrated that baits containing malathion and chlorpyrifos deterred flies from feeding on them. In contrast, no such deterrence was detected with baits containing spinosad, fipronil and protein alone. These results demonstrated that the type of toxicant mixed with protein bait sprays can influence the attraction and feeding responses of B. tryoni. Therefore the process of screening toxicants for use in protein bait mixtures is important and should entail field and laboratory tests.
In terms of toxicity, protein baits mixed with malathion and chlorpyrifos caused significantly higher fly mortality and demonstrated a more rapid fly knock down than did spinosad, fipronil and protein alone as the control. Spinosad however was a slow acting toxicant, causing a gradual increase in fly mortality over time.
Fly mortality obtained with protein bait mixtures containing malathion, chlorpyrifos and fipronil, applied on citrus leaves, and weathered out doors for up to 6 days did not vary significantly from freshly applied baits. However, the residual effectiveness of bait mixed with spinosad waned significantly after 3 days of out door weathering. Fly mortality caused by 3 day aged spinosad bait mixture was significantly lower than fresh bait mixtures, suggesting a rapid break down of spinosad under field conditions.
The parasitism rates of the two most important parasitoids of red scales, A. lingnanensis and C. bifasciata, measured before and after commencement of fruit fly bait spraying in two commercial citrus orchards, did not show any significant negative trend. Aphytis were not attracted to Pinnacle protein, the most commonly used fruit fly protein lure in Australia. A significantly higher number of Aphytis were attracted to honey solution and protein bait mixed with 20% sugar, compared to protein bait alone. A no-choice test further confirmed this result, demonstrating no difference in attraction between protein and water.
Protein bait containing malathion, chlorpyrifos, fipronil, and spinosad, fresh and weathered for up to 12 days, caused high mortality in Aphytis. In contrast protein bait mixed with spinosad caused a lower Aphytis mortality after 12 days out door weathering, compared to chlorpyrifos bait mixture. However, for other weathering periods, no such differences in mortality between the treatments were observed. In addition, the parasitizing capacity of Aphytis, after being exposed to these weathered residues, was reduced. Except for the control, aged bait mixtures significantly reduced the fecundity of Aphytis. Therefore, while integrating chemical based field control along with bio-control agents, appropriate measures should be in place to reduce the negative impacts of toxic residues.
Overall, the findings from this study indicate that spinosad is a suitable alternative to the older toxicants, for incorporation into fruit fly protein baits. Moreover, fruit fly protein baits in the field are less likely to disrupt the activites of important natural enemies. However, chemical-based control of insect pests in a cropping system should be designed carefully with the objective to prevent potential harm to susceptible biological control agents such as Aphytis.<br>Thesis (Masters)<br>Master of Philosophy (MPhil)<br>Griffith School of Environment<br>Faculty of Science, Environment, Engineering and Technology<br>Full Text
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De, Lima Ivanildo Soares. "Behaviour and chemical ecology of the South American fruit fly, Anastrepha fraterculus Wiedemann (Diptera : tephritidae)." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295673.
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Johansson, Björn G. "Chemical Communication and Mate Choice : Investigations into the Meaning of a Fruit Fly Pheromone." Doctoral thesis, Uppsala University, Department of Ecology and Evolution, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4840.
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<p>Chemical signals are the most widely used form of sexual communication throughout the living world. However, there is in general little knowledge about what these signals actually communicate. The role of chemical signals, i.e. pheromones, in sexual behaviour has traditionally been seen as restricted to mate attraction and species recognition. This thesis reviews the evidence for pheromones as indicators of mate quality, and then investigates three important factors for mate quality signals – individual variation, heritability and cost – by using the male pheromone of the lekking fruit fly <i>Drosophila grimshawi</i> as a model.</p><p>The experiments presented indicate that the pheromone of <i>D. grimshawi</i> has multiple functions, and that these functions vary with social context. Thus, with regard to females, the pheromone seems to act mainly as a species/mate recognition signal, since females show little preference for the amount of pheromone deposited by a male. Moreover, males invest less in pheromone production when subjected to females as compared to when subjected to rival males. However, the pheromone seems to be costly in production since males that invest much in pheromone deposition has a shorter lifespan. This suggests a function for the pheromone in male-male interactions. Males can distinguish their own pheromone depositions from those of a strange male, and also discriminate between pheromone depositions from one and two strange males. This might give them the ability to assess the size of a lek and the competitive capacities of rivals, information that should be useful when optimizing sexual behaviour.</p><p>In conclusion, the pheromone seems to act as an honest mate/competitor quality signal in some social contexts, and as a non-costly species/mate recognition signal in other. In addition, I show for the first time that a chemical signal has differential fitness costs, and that an insect is able to distinguish between individual odour signatures.</p>
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Jayaraman, Vivek Winfree Erik Laurent Gilles. "Neural circuit dynamics and ensemble coding in the locust and fruit fly olfactory system /." Diss., Pasadena, Calif. : California Institute of Technology, 2007. http://resolver.caltech.edu/CaltechETD:etd-05192007-195030.
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Rohrig, Eric A. "A floral derived attractant for the tephritid fruit fly parasitoid Diachasmimorpha longicaudata (Hymenoptera : Braconidae)." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0014140.
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