No description available.

Reproductive traits are often thought of as fixed, genetically determined properties. However, such traits are often dynamic, exhibiting different expression patterns depending on context. Both internal state and external environment can have a strong effect on how traits are expressed. Variation in these factors across the lifetime of an individual should select for flexibility in trait expression, rather than fixation.My dissertation work examines how mating behavior and testes size respond to several previously unexplored contextual factors, using Rhagoletis juglandis, the walnut fly, as a model system. For mating behavior, I predicted that differences in female reproductive state (egg load) and experience with host resource would impact mating decisions. For testes size, I predicted that social environment (sex ratio) and changes in resource environment would determine testes size.Behavioral observations of flies showed that a large egg load increased the likelihood of copulation, while prior experience with host fruit decreased copulation time. These results are the first to distinguish effects of experience on physiological state from other effects of experience in the context of mating behavior.Manipulation of the sex ratio revealed that males develop larger testes when reared in an environment with many potential competitors. This is the first study to show that that allocation to a male reproductive organ can change depending on the sex ratio. My studies showed that resource environment is also important in determining testes investment patterns. When adult males are deprived of protein, they develop smaller testes. A stable isotope analysis of testes further confirms that resource environment is important for testes development. Males rely more on nitrogen derived at the larval stage than at the adult stage, but adult carbon sources are a large component of testes mass.In sum, this dissertation demonstrates the importance of context in the expression of reproductive traits. Recent research has shown that such traits can respond more dynamically to context than previously thought, but this area of research is young. My results help provide a greater understanding of the processes shaping the evolution of reproductive traits.

Os microrganismos presentes no intestino de insetos podem desempenhar importantes funções na biologia de seus hospedeiros, como na nutrição, detoxificação de compostos de defesas das plantas, prevenção da infecção por patógenos e produção de semioquímicos importantes nas interações de insetos. O primeiro passo para entender as funções da microbiota do intestino na biologia de insetos consiste na identificação dessas comunidades. Neste trabalho, a diversidade de bactérias do intestino de larvas e adultos da mosca-das-frutas sul-americana, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), foi determinada por métodos baseados ou não no cultivo. O método baseado no cultivo foi utilizado no estudo da diversidade da microbiota de população de laboratório mantida em frutos de mamão, avaliando-se a diversidade presente no intestino de larvas e em duas regiões distintas do intestino de adultos, o papo e o intestino médio+posterior. A análise metagenômica pela avaliação de bibliotecas de 16S rDNA foi aplicada ao estudo da diversidade da microbiota associada a moscas oriundas de diferentes frutos hospedeiros (guabiroba, nêspera, maçã, mamão e pitanga). As análises por cultivo permitiram a identificação de 25 filotipos associados ao intestino de larvas e adultos, sendo a diversidade em larvas bem distinta daquela de adultos. Os Filos Actinobacteria, Bacteroidetes, Firmicutes e Proteobacteria foram representados por 10 famílias, sendo Enterobacteriaceae a mais abundante. Filotipo próximo à enterobacteriacea Cedecea davisae foi o único a ocorrer no intestino de larvas e papo e intestino de adultos. A análise metagenômica dos insetos obtidos em diferentes frutos hospedeiros estendeu a diversidade anteriormente identificada aos Filos Cyanobacteria, Deinococcus, Elusimicrobia, Planctomycetes e Verrucomicrobia. Novamente, Proteobacteria se destacou como o mais diverso. Esse estudo demonstrou que a comunidade microbiana associada ao intestino de A. fraterculus é inteiramente influenciado pelo fruto hospedeiro utilizado, sendo raros os filotipos compartilhados por insetos em diferentes frutos. A composição da microbiota do intestino do adulto é muito menos diversa do que a da larva, independentemente do fruto utilizado. Mas vários filotipos, como aqueles próximos a Acinetobacter bereziniae, Cedecea davisae, Comamonas koreensis, Enterobacter asburiae, Empedobacter brevis e Hydrogenophilus hirschii, além do parasita intracelular Wolbachia pipientis, mantiveram-se associadas ao intestino de larvas e adultos de A. fraterculus, mesmo após a metamorfose. A análise das comunidades bacterianas de A. fraterculus sugere que as variações em suas estruturas estão relacionadas ao substrato alimentar utilizado pelo inseto. / The microorganisms present in the insect gut can play important roles in the biology of their hosts such as nutrition, detoxification of compounds defenses of plants, preventing infection by pathogens and production of important semiochemicals in insect interactions. The first step to understanding the functions of the gut microbiota in insect biology is the identification of these communities. In this work, the diversity of gut bacteria in larvae and adult South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) , were determined by methods based on the cultivation or not . The method based on the cultivation was used to study the microbial diversity of laboratory population maintained in papaya fruits, evaluating the diversity present in the gut of larvae and in two distinct regions of the intestine of adults, the crop and midgut + hindgut. The analysis of metagenomic libraries for evaluation of 16S rDNA was applied to the study of the diversity of the microbiota associated with fruit flies from different hosts (guabiroba , medlar , apple, papaya and pitanga). The analysis by cultivation allowed the identification of 25 phylotypes associated with the gut of larvae and adults, larvae diversity being quite different from that of adults. The phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria were represented by 10 families, Enterobacteriaceae being the most abundant. Filotipo near Enterobacteriacea Cedecea davisae strains was the only one to occur in the gut of larvae and adult chat and intestine. The metagenomic analysis of insects obtained in different fruit hosts extended to the diversity previously identified phyla Cyanobacteria, Deinococcus, Elusimicrobia, Planctomycetes and Verrucomicrobia. Again, Proteobacteria stood out as the most diverse. This study showed that the microbial community associated with the intestine of A. fraterculus is entirely influenced by host fruit used are rare phylotypes shared by insects in different fruits. The composition of the gut microbiota in adults is far less diverse than the larvae, irrespective of the fruit used. But several phylotypes, such as those near Acinetobacter bereziniae, Cedecea davisae strains, Comamonas koreensis, Enterobacter asburiae, Empedobacter brevis and Hydrogenophilus hirschii, besides the intracellular parasite Wolbachia pipientis, remained attached to the gut of larvae and adults of A. fraterculus, even after metamorphosis. The analysis of bacterial communities of A. fraterculus suggests that variations in their structures are related to the food substrate used by the insect.

Os microrganismos presentes no intestino de insetos podem desempenhar importantes funções na biologia de seus hospedeiros, como na nutrição, detoxificação de compostos de defesas das plantas, prevenção da infecção por patógenos e produção de semioquímicos importantes nas interações de insetos. O primeiro passo para entender as funções da microbiota do intestino na biologia de insetos consiste na identificação dessas comunidades. Neste trabalho, a diversidade de bactérias do intestino de larvas e adultos da mosca-das-frutas sul-americana, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), foi determinada por métodos baseados ou não no cultivo. O método baseado no cultivo foi utilizado no estudo da diversidade da microbiota de população de laboratório mantida em frutos de mamão, avaliando-se a diversidade presente no intestino de larvas e em duas regiões distintas do intestino de adultos, o papo e o intestino médio+posterior. A análise metagenômica pela avaliação de bibliotecas de 16S rDNA foi aplicada ao estudo da diversidade da microbiota associada a moscas oriundas de diferentes frutos hospedeiros (guabiroba, nêspera, maçã, mamão e pitanga). As análises por cultivo permitiram a identificação de 25 filotipos associados ao intestino de larvas e adultos, sendo a diversidade em larvas bem distinta daquela de adultos. Os Filos Actinobacteria, Bacteroidetes, Firmicutes e Proteobacteria foram representados por 10 famílias, sendo Enterobacteriaceae a mais abundante. Filotipo próximo à enterobacteriacea Cedecea davisae foi o único a ocorrer no intestino de larvas e papo e intestino de adultos. A análise metagenômica dos insetos obtidos em diferentes frutos hospedeiros estendeu a diversidade anteriormente identificada aos Filos Cyanobacteria, Deinococcus, Elusimicrobia, Planctomycetes e Verrucomicrobia. Novamente, Proteobacteria se destacou como o mais diverso. Esse estudo demonstrou que a comunidade microbiana associada ao intestino de A. fraterculus é inteiramente influenciado pelo fruto hospedeiro utilizado, sendo raros os filotipos compartilhados por insetos em diferentes frutos. A composição da microbiota do intestino do adulto é muito menos diversa do que a da larva, independentemente do fruto utilizado. Mas vários filotipos, como aqueles próximos a Acinetobacter bereziniae, Cedecea davisae, Comamonas koreensis, Enterobacter asburiae, Empedobacter brevis e Hydrogenophilus hirschii, além do parasita intracelular Wolbachia pipientis, mantiveram-se associadas ao intestino de larvas e adultos de A. fraterculus, mesmo após a metamorfose. A análise das comunidades bacterianas de A. fraterculus sugere que as variações em suas estruturas estão relacionadas ao substrato alimentar utilizado pelo inseto. / The microorganisms present in the insect gut can play important roles in the biology of their hosts such as nutrition, detoxification of compounds defenses of plants, preventing infection by pathogens and production of important semiochemicals in insect interactions. The first step to understanding the functions of the gut microbiota in insect biology is the identification of these communities. In this work, the diversity of gut bacteria in larvae and adult South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) , were determined by methods based on the cultivation or not . The method based on the cultivation was used to study the microbial diversity of laboratory population maintained in papaya fruits, evaluating the diversity present in the gut of larvae and in two distinct regions of the intestine of adults, the crop and midgut + hindgut. The analysis of metagenomic libraries for evaluation of 16S rDNA was applied to the study of the diversity of the microbiota associated with fruit flies from different hosts (guabiroba , medlar , apple, papaya and pitanga). The analysis by cultivation allowed the identification of 25 phylotypes associated with the gut of larvae and adults, larvae diversity being quite different from that of adults. The phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria were represented by 10 families, Enterobacteriaceae being the most abundant. Filotipo near Enterobacteriacea Cedecea davisae strains was the only one to occur in the gut of larvae and adult chat and intestine. The metagenomic analysis of insects obtained in different fruit hosts extended to the diversity previously identified phyla Cyanobacteria, Deinococcus, Elusimicrobia, Planctomycetes and Verrucomicrobia. Again, Proteobacteria stood out as the most diverse. This study showed that the microbial community associated with the intestine of A. fraterculus is entirely influenced by host fruit used are rare phylotypes shared by insects in different fruits. The composition of the gut microbiota in adults is far less diverse than the larvae, irrespective of the fruit used. But several phylotypes, such as those near Acinetobacter bereziniae, Cedecea davisae strains, Comamonas koreensis, Enterobacter asburiae, Empedobacter brevis and Hydrogenophilus hirschii, besides the intracellular parasite Wolbachia pipientis, remained attached to the gut of larvae and adults of A. fraterculus, even after metamorphosis. The analysis of bacterial communities of A. fraterculus suggests that variations in their structures are related to the food substrate used by the insect.

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.