Made available in DSpace on 2014-10-09T12:40:59Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:32Z (GMT). No. of bitstreams: 1 04015.pdf: 1118706 bytes, checksum: cfb96bf2d7bcbe122082fa953b52e435 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Os estudos de diversidade de espécies são importantes para compreender os aspectos ecológicos das comunidades de moscas-das-frutas. Todavia, nos estudos de diversidade de moscas-das-frutas, têm sido discutidos principalmente os espécimes coletados em armadilhas tipo McPhail. Entretanto, no presente estudo, além dos dados de armadilhas, a diversidade foi também baseada nas moscas-das-frutas obtidas diretamente dos hospedeiros. Destsa forma, foi realizada, pela primeira vez, uma análise comparativa de espécies de Anastrepha coletadas em uma mesma área em armadilhas e nos hospedeiros. A diversidade de espécies de Anastrepha foi discutida, pela primeira vez, por meio da modelagem espacial. O levantamento de moscas-das-frutas foi realizado em 48 pontos de coleta distribuídos pelo campus \"Luiz de Queiroz\", Piracicaba, SP. Uma armadilha, contendo proteína hidrolisada de milho, foi instalada em cada ponto de coleta e os hospedeiros foram amostrados nas proximidades. As coletas com armadilhas foram realizadas semanalmente de julho de 1998 a junho de 1999. Os hospedeiros (26 espécies) foram amostrados de janeiro a dezembro de 1999. As espécies de Anastrepha coletadas nos dois métodos foram comparadas por meio de parâmetros faunísticos, índices de diversidade e flutuação populacional. As moscas-das-frutas obtidas nos hospedeiros foram comparadas por meio da análise de agrupamento (Sorensen e Bray-Curtis). A interação das espécies, nos dois métodos de coleta, foi baseada no heat map graph. O padrão de distribuição da diversidade foi analisado por meio de modelagem espacial (Krigagem). Foram coletadas 19.660 fêmeas de espécies de Anastrepha em armadilhas e 10.453 nos hospedeiros. Foram capturadas mais espécies de Anastrepha nas armadilhas (18) do que nos hospedeiros (7). Nas armadilhas, A. fraterculus, A. obliqua, A. bistrigata, A. pseudoparallela, A. barbiellinii e A. sororcula foram predominantes, mas somente A. fraterculus foi a mais abundante. Nos frutos, A. obliqua, A. fraterculus e A. bisgrigata foram predominantes, mas somente A. obliqua foi a mais abundante. A maior abundância de espécimes foi obtida em seriguela e a maior riqueza de espécies foi obtida em goiaba e em citros. Sete grupos foram formados pela presença e ausência de espécies de Anastrepha pelo coeficiente de similaridade de Sorensen e cinco grupos foram formados pela abundância de espécimes pelo coeficiente de Bray-Curtis. As características da comunidade (diversidade, riqueza, equitabilidade e dominância) diferiram nos dois métodos de coleta. Das seis espécies compartilhadas nas armadilhas e nos hospedeiros, apenas A. fraterculus e A. obliqua tiveram interação mais forte com os dois métodos de coleta. O pico populacional de espécies de Anastrepha ocorreu em setembro (armadilhas) e em fevereiro (hospedeiros). A disponibilidade de hospedeiros foi o fator que mais interferiu na dinâmica populacional. A diversidade de espécies de Anastrepha se concentrou nas áreas próximas aos fragmentos de mata. A maior diversidade ocorreu nas proximidades dos fragmentos acima de 100.000 m2. / Studies on diversity of fruit fly species are crucial for understanding ecological aspects of their communities of fruit flies. These studies have been carried out mostly on fruit flies collected in McPhail-type traps. Consequently, diversity of fruit flies has been discussed mostly on trapped specimens. Nonetheless, in this study, besides trapped specimens, diversity was also based on specimens obtained directly from hosts. Thus, it was performed, for the first time, a comparative analysis of Anastrepha species from same area collected in traps and from hosts. Additionally, diversity of Anastrepha species was discussed, for the first time, based on spatial modeling. Fruit fly survey was performed in 48 collecting points distributed throughout \"Luiz de Queiroz\" campus, in Piracicaba, state of São Paulo, Brazil. A trap, baited with hydrolyzed corn protein, was installed at each collecting point, and fruits nearby were sampled. Collections with traps were carried out weekly from July 1998 to June 1999. Hosts (26 species) were sampled from January to December 1999. Anastrepha species collected in both methods were compared by mean of faunistic parameters, diversity indices and population fluctuation. Fruit flies obtained from hosts were compared by mean cluster analysis (Sorensen e Bray-Curtis). The species interaction, in both collecting methods, was based on heat map graph. The diversity distribution pattern was analysed by mean of the spatial modelling (Kriging). A total of 19,660 females of Anastrepha species were collected in the traps, and 10,453 were obtained from hosts. It was captured more Anastrepha species (18) in the traps than in the hosts (7). In the traps, A. fraterculus, A. obliqua, A. bistrigata, A. pseudoparallela, A. barbiellinii and A. sororcula were more abundant, but only A. fraterculus was predominant. In the hosts, A. obliqua, A. fraterculus and A. bistrigata were predominant, but only A. obliqua was more abundant. The greatest abundance of specimens was obtained in red mombin and the greatest species richness in guava and citrus. Seven groups were formed by presence and absence of Anastrepha species for the Sorensen similarity coefficient, and five groups for the abundance of specimens for the Bray-Curtis coefficient. The community characteristics (diversity, richness, equitability, and dominance) differ in both collecting methods. Six species were collected in both traps and hosts, but only A. fraterculus and A. obliqua had stronger interaction with these collecting methods. The population peak of Anastrepha species occurred in September (traps) and in February (hosts). The host availability was the main factor that interfered with population dynamic. The Anastrepha species diversity concentrated in areas nearby of forest fragments. The highest diversity was adjacent to forest fragments above 100,000 m2.

A rich diversity of social behaviours exists in the animal kingdom, and these behaviours have evolved to perform a variety of adaptive functions. Social behaviours show variation both among and within species, however the mechanisms that give rise to this variation are not well understood. Using fruit flies (Drosophila melanogaster), my goal was to uncover the genetic and behavioural mechanisms that underpin natural variation in two different social behaviours: sociability and sexual aggression. First, I showed that sociability, which is the tendency of animals to engage in friendly activities together, is influenced by indirect genetic effects (IGEs), and that encounters among individuals drive these effects (Chapter 2). I then showed that sociability and social plasticity have low-moderate heritability (Chapter 3), and sociability is not correlated between the sexes or with activity. I then generated lineages of flies with high and low sociability using artificial selection (Chapter 4). The evolved lineages had significantly diverged sociability which was not associated with fitness measures or nearest-neighbor distances, but was negatively correlated with intrasexual aggression (Chapter 4). Finally, in sexual aggression, which I quantified as male forced copulation rate, I showed that evolved differences and differences due to social plasticity were both associated with the differential expression of many genes, but only a few of these genes were significant in both (Chapter 5). I also showed that these sets of genes are enriched in neuropeptide hormone and serotonin gene ontology categories, and that 4 of 7 chosen genes were validated for their effects on sexual aggression. Overall, this thesis sheds light on the complex mechanisms that underlie variation in these social behaviours, and it paves the way for future research to further elucidate some of these mechanisms, especially on the genetic basis of sociability using the evolved lineages I generated. / Thesis / Doctor of Philosophy (PhD) / Individual animals tend to vary in many traits including social behaviours. Using fruit flies, my goal was to understand what causes individuals to vary in two social behaviours: sociability and sexual aggression. I found that highly sociable flies tended to influence other flies to become more sociable due to a change in how much these flies interacted. I also found that individual differences in sociability are moderately heritable, and the genetic variation contributing to this is different between the sexes. Also, less sociable flies tended to be more aggressive than highly sociable flies. Finally, for sexual aggression, I showed that variation in a male’s success in forcibly mating with a female was associated with changes in the expression of hundreds of genes, but these changes were mostly unique for evolved versus environmentally induced variation. Future work will similarly look to identify genes involved with individual differences in sociability.

Os levantamentos das espécies de Anastrepha foram realizados com armadilhas do tipo McPhail contendo torula (atraente alimentar) em: (1) Monte Alegre do Sul (janeiro de 2002 a dezembro de 2003) e (2) Monte Alto (janeiro a dezembro de 2004). Foram capturados 30.516 espécimes (15.770 fêmeas e 14.746 machos) em Monte Alegre do Sul, 22.825 exemplares (11.739 machos e 11.086 fêmeas) em Monte Alto. As identificações foram baseadas nas fêmeas. Foram identificadas 13 espécies em Monte Alegre do Sul, das quais, A. fraterculus e A. bistrigata foram predominantes. Em 2003, houve maior diversidade de espécies (11 das 13 espécies). Em Monte Alto, foram identificadas oito espécies, sendo A. fraterculus e A. sororcula predominantes. Os picos populacionais variaram entre as três principais espécies em Monte Alegre do Sul. Para A. fraterculus (Wied.), os picos ocorreram em março/abril e setembro/outubro; para A. bistrigata e A. obliqua, de março a maio. Em Monte Alto, os picos populacionais de A. fraterculus ocorreram em janeiro e outubro de 2004, sendo o acme populacional em outubro. Anastrepha sororcula apresentou um único pico em janeiro, mantendo-se com baixa população no restante do ano. A disponibilidade de goiaba foi o fator principal que influenciou o nível populacional das principais espécies de Anastrepha. Não ficou evidente a influência direta dos fatores climáticos sobre as populações das moscasdas- frutas em Monte Alegre do Sul. Em Monte Alto, os picos populacionais das principais espécies foram um pouco diferentes, ou seja, A. fraterculus teve dois picos (janeiro e outubro), um deles sem a presença de frutos no pomar (janeiro), e A. sororcula ocorreu somente em janeiro (sem frutos no pomar). Houve correlação positiva entre o alto índice de captura de A. sororcula com a precipitação pluvial do município. / Surveys of the Anastrepha species using torula-baited McPhail traps (food attractant) were carried out in Monte Alegre do Sul (January 2002 to December 2003) and Monte Alto (January to December 2004). A total of 30,516 specimens (15,770 females and 14,746 males) were captured in Monte Alegre do Sul, and 22,825 specimens (11,739 males and 11,086 females) in Monte Alto. Species identification was exclusively based on females. Thirteen species were recorded in Monte Alegre do Sul, from which A. fraterculus and A. bistrigata were predominant. The diversity of species was greater in 2003 than in 2004 (11 out of 13 species). Eight species were identified in Monte Alto, from which A. fraterculus and A. sororcula were predominant. The population peaks varied among the three major species in Monte Alegre do Sul. Anastrepha fraterculus peaked in March/April and September/October, and A. bistrigata and A. obliqua from March to May. In Monte Alto, population peaks of A. fraterculus occurred in January and October 2004, with a higher peak in October. Anastrepha sororcula showed a single peak in January, maintaining a low population level during the year. The availability of guava was the main factor that influenced the population level of the major Anastrepha species. No clear indication of the effect of climatic factors on the population density of fruit flies in Monte Alegre do Sul was obtained. The population peaks of the major species were slightly different in Monte Alto as compared to Monte Alegre do Sul, as A. fraterculus peaked twice (January and October), once in January when fruits were unavailable. The peak occurrence of Anastrepha sororcula (January) also coincided with the unavailability of fruits in the orchard. A positive correlation between the high rate of capture of A. sororcula with rainfall in the orchard in Monte Alegre was verified.

Made available in DSpace on 2016-08-12T19:18:29Z (GMT). No. of bitstreams: 1 RaimundoIRS_TESE.pdf: 1193128 bytes, checksum: 507928ca7e543ba3ae01570b0c9bc9ee (MD5) Previous issue date: 2014-09-01 / Brazil, producing more than 40 million ton of fruits in 2013, is one of the three greatest fruit producer in the world. In spite of the potential, we see some difficulties on the management of the cultures, specially phytosanitary problems. Fruit flies (Diptera: Tephritidae) represent one of the great phytosanitary for fruit growing due to damage on the fruits and quarantine restrictions, whose loss is equivalent one billion dollars per year. Thus, this work aimed to know the species of fruit flies through some traps, as well as accomplishing a prospection of host vegetable species on the region Baixo Jaguaribe, Ceará. The study was accomplished from 2010 to 2013, being divided in two stages: capture of flies, accomplished through McPhail traps Hydrolysed Maize Protein at 5% and periodical collections of fruits form cultivated or wild species. Identification of fruit flies species was accomplished in Applied Entomology Laboratory of UFERSA, considering female morphological characters. The number of fruit flies captured with traps was 6.350 and 9.626 were captured using fruit collection, being collected 64 vegetable species, from which 17 were infected by Ceratitis capitata and/or Anastrepha spp. C. capitata species represent approximately 75% of collected species; six species Anastrepha: Anastrepha sororcula, A. zenildae, A. obliqua, A. dissimilis, A. pickeli and A. alveata, being the last one registered for the first time in the state of Ceará. A. sororcula represents 72% of females and is associated specially to guava. A. zenildae is associated to guava, juazeiro, castanhola and murici and A. obliqua is associated to cajarana. The greatest infestation index for C. capitata were observed in castanhola, sapoti, seriguela, pitanga, acerola, guava and murici and for Anastrepha spp., murici, guava and juazeiro / O Brasil, com uma produção superior a 40 milhões de toneladas de frutas produzidas no ano de 2013, é um dos três maiores produtores de frutas do mundo. Apesar de todo este potencial, ainda nos deparamos com algumas dificuldades no manejo das culturas com ênfase aos problemas fitossanitários. As moscas-das-frutas (Diptera: Tephritidae) constituem um dos grandes problemas fitossanitários para a fruticultura em função dos danos diretos nos frutos e em virtude das restrições quarentenárias, cujos prejuízos chegam a 1 bilhão de dólares anuais. Portanto, este trabalho teve como objetivo conhecer as espécies de moscas-das-frutas por meio de armadilhas, como também realizar uma prospecção de espécies vegetais hospedeiras na região do Baixo Jaguaribe, Ceará. O estudo foi realizado durante o período de 2010 a 2013, sendo dividido em duas etapas: captura das moscas, realizadas através do uso de armadilhas McPhail com proteína hidrolisada de milho a 5% e coletas periódicas de frutos de espécies cultivadas e/ou silvestre. A identificação das espécies de moscas-das-frutas foi realizada no Laboratório de Entomologia Aplicada da UFERSA, com base em caracteres morfológicos das fêmeas. O número de moscas-das-frutas capturadas com uso das armadilhas foi de 6.350 e por meio de coletas de frutos 9.626 exemplares, sendo coletados frutos de 64 espécies vegetais, das quais 17 estavam infestadas por Ceratitis capitata e/ou Anastrepha spp. A espécie C. capitata representa cerca de 75% das espécies coletadas; foram identificadas seis espécies Anastrepha: Anastrepha sororcula, A. zenildae, A. obliqua, A. dissimilis, A. pickeli e A. alveata, sendo esta última registrada pela primeira vez no estado do Ceará. A. sororcula representa 72% do total de fêmeas e está associada principalmente a goiaba; A. zenildae a goiaba, juazeiro, castanhola e murici e A. obliqua a cajarana. Os maiores índices de infestação para C. capitata foram verificados em castanhola, sapoti, seriguela, pitanga, acerola, goiaba e murici e para Anastrepha spp. murici, goiaba e juazeiro

This thesis has two focuses. The first problem facing the olive industry in the Eastern Cape is the growers’ perceptions of both what the industry will provide them and what a pest management program might entail. The second focus is the biology of olive pests in the Eastern Cape in terms of understanding their populations and their natural enemies on private farms, with future hopes of understanding how Integrated Pest Management strategies can be developed for this crop. Eastern Cape private farmers, small-scale farmers and workers from agricultural training institutions were interviewed regarding the history and cultivation of the local olive crop. Only one commercially viable olive grove was identified; other groves were small, experimental pilot ventures. The introduction of olives to small-scale farmers and agricultural training schools was generally a top-down initiative that led to a lack of sense of ownership and the trees being neglected. Other problems included poor human capital; poor financial capital; lack of adequate support; lack of knowledge transfer and stability; lack of communication and evaluation procedures of the project; miscommunication; and finally, olive pests. Apart from hesitancy to plant at a commercial scale, the main problem facing private farmers (Varnam Farm, Hewlands Farm and Springvale Farm) was pests. Therefore an investigation of pests from private farms was conducted ranging from collection of cultivated and wild olive fruit and flea beetle larvae for parasitism, trapping systems both for fruit flies and olive flea beetle adults. A survey of olive fruits yielded larval fruit flies of the families Tephritidae (Bactrocera oleae (Rossi), B. biguttula (Bezzi) and Ceratitis capitata (Wiedemann)) and Drosophilidae (Drosophila melanogaster (Meigen)) from wild olives (O. europaea cuspidata (Wall. ex G. Don) Cif.) but none from cultivated olives (O. e. europaea L.). Braconid wasps (Opiinae and Braconinae) were reared only from fruits containing B. oleae and B. biguttula. This suggests that B. oleae is not of economic significance in the Eastern Cape, perhaps because it is controlled to a significant level by natural enemies, but B. biguttula may be a potential economic pest. A survey of adult fruit flies using ChamP traps baited with ammonium bicarbonate and spiroketal capsules and Sensus trap baited with methyl eugenol and Questlure confirmed the relative importance of B. biguttula over B. oleae. ChamP traps were over 50 times better than Sensus traps for mass trapping of B. biguttula but both were ineffective for trapping B. oleae and C. capitata. Six indigenous flea beetles of the genus Argopistes Motschulsky (Chrysomelidae: Alticinae) were found, three described by Bryant in 1922 and 1944 and three new species. Their morphology was investigated by scanning electron microscopy and mutivariate morphometric analysis. The leaf-mining larvae are pests of wild and cultivated olives in South Africa and threaten the local olive industry. At Springvale Farm, A. oleae Bryant and A. sexvittatus Bryant preferred the upper parts of trees, near new leaves. Pseudophanomeris inopinatus (Blkb.) (Braconidae) was reared from 23 Argopistes larvae. The beetle larvae might not be controlled to a significant level by natural enemies because the rate of parasitism was low. The olive flea beetles showed no attraction to traps containing various volatile compounds as baits. The lace bug, Plerochila australis Distant (Tingidae), was sometimes a pest. It showed a preference for the underside of leaves on the lower parts of the trees. A moth, Palpita unionalis Hübner (Crambidae), was reared in very low numbers and without parasitoids. A twig-boring beetle larva, chalcidoid parasitoids and seed wasps of the families Eurytomidae, Ormyridae and Eupelmidae were also recorded.

Os levantamentos das espécies de Anastrepha foram realizados com armadilhas do tipo McPhail contendo torula (atraente alimentar) em: (1) Monte Alegre do Sul (janeiro de 2002 a dezembro de 2003) e (2) Monte Alto (janeiro a dezembro de 2004). Foram capturados 30.516 espécimes (15.770 fêmeas e 14.746 machos) em Monte Alegre do Sul, 22.825 exemplares (11.739 machos e 11.086 fêmeas) em Monte Alto. As identificações foram baseadas nas fêmeas. Foram identificadas 13 espécies em Monte Alegre do Sul, das quais, A. fraterculus e A. bistrigata foram predominantes. Em 2003, houve maior diversidade de espécies (11 das 13 espécies). Em Monte Alto, foram identificadas oito espécies, sendo A. fraterculus e A. sororcula predominantes. Os picos populacionais variaram entre as três principais espécies em Monte Alegre do Sul. Para A. fraterculus (Wied.), os picos ocorreram em março/abril e setembro/outubro; para A. bistrigata e A. obliqua, de março a maio. Em Monte Alto, os picos populacionais de A. fraterculus ocorreram em janeiro e outubro de 2004, sendo o acme populacional em outubro. Anastrepha sororcula apresentou um único pico em janeiro, mantendo-se com baixa população no restante do ano. A disponibilidade de goiaba foi o fator principal que influenciou o nível populacional das principais espécies de Anastrepha. Não ficou evidente a influência direta dos fatores climáticos sobre as populações das moscasdas- frutas em Monte Alegre do Sul. Em Monte Alto, os picos populacionais das principais espécies foram um pouco diferentes, ou seja, A. fraterculus teve dois picos (janeiro e outubro), um deles sem a presença de frutos no pomar (janeiro), e A. sororcula ocorreu somente em janeiro (sem frutos no pomar). Houve correlação positiva entre o alto índice de captura de A. sororcula com a precipitação pluvial do município. / Surveys of the Anastrepha species using torula-baited McPhail traps (food attractant) were carried out in Monte Alegre do Sul (January 2002 to December 2003) and Monte Alto (January to December 2004). A total of 30,516 specimens (15,770 females and 14,746 males) were captured in Monte Alegre do Sul, and 22,825 specimens (11,739 males and 11,086 females) in Monte Alto. Species identification was exclusively based on females. Thirteen species were recorded in Monte Alegre do Sul, from which A. fraterculus and A. bistrigata were predominant. The diversity of species was greater in 2003 than in 2004 (11 out of 13 species). Eight species were identified in Monte Alto, from which A. fraterculus and A. sororcula were predominant. The population peaks varied among the three major species in Monte Alegre do Sul. Anastrepha fraterculus peaked in March/April and September/October, and A. bistrigata and A. obliqua from March to May. In Monte Alto, population peaks of A. fraterculus occurred in January and October 2004, with a higher peak in October. Anastrepha sororcula showed a single peak in January, maintaining a low population level during the year. The availability of guava was the main factor that influenced the population level of the major Anastrepha species. No clear indication of the effect of climatic factors on the population density of fruit flies in Monte Alegre do Sul was obtained. The population peaks of the major species were slightly different in Monte Alto as compared to Monte Alegre do Sul, as A. fraterculus peaked twice (January and October), once in January when fruits were unavailable. The peak occurrence of Anastrepha sororcula (January) also coincided with the unavailability of fruits in the orchard. A positive correlation between the high rate of capture of A. sororcula with rainfall in the orchard in Monte Alegre was verified.

Ceratitis fasciventris, Ceratitis anonae and Ceratitis rosa are polyphagous agricultural pests originating from African continent. Their behaviour is heavily altered by pheromones. Insect chemical communication channels are species-specific, represents taxonomic and reproduction barriers. Taxonomy of this group (so-called Ceratitis FAR complex) is unclear. Therefore new chemical approaches along with genetic tests for identification of entities within the cryptic species FAR complex are being developed. To study multi-component mixtures of male volatiles originating from the three mentioned fruit fly species, comprehensive two-dimensional gas chromatography with time- of-flight mass spectrometer (GC×GC-TOFMS) was used. A number of compounds were identified, out of which 23 were found to be distributed and shared among the studied species, 11 out of these were present in all three species. Analyses of male pheromone volatiles, using gas chromatography combined with electroantennographic detector (GC-EAD) revealed 4 common compounds with antennal activity shared among three studied species: methyl (E)-hex-3-enoate, 6-methylhept-5-en-2- one, linalool, and methyl (2E,6E)-farnesoate. The species-specific EAD active compounds in C. fasciventris were esters of isomers of hexenoic acid, whereas isomers of...

This thesis is a contribution to feminist laboratory studies and a critical engagement with the natural sciences, or more precisely research on the biochemical workings and deadly relations of Alzheimer’s disease emanating from a year of field work in a Drosophila fly lab. The natural sciences have been a point of fascination within the field of gender studies for decades. Such sciences produce knowledge on what gets to count as nature and natural, healthy or sick, normal or not, and they have done it with great societal authority and impact throughout European modernity. However, feminist technoscience scholars argue that science and knowledge is socially produced, and political too. Concepts such as nature, animal, human, body, sex, and life itself are not simply given natural realities but phenomena processed through the naturecultures of the laboratory. Situated within such theoretical and methodological approaches, this thesis wonders how scientific facts about Alzheimer’s disease are made in the lab today. What kinds of realities, bodies and ethico-political concerns are enacted? Who gets to live and who gets to die in everyday laboratory practices? Theoretically, the thesis is grounded, particularly, within Karen Barad’s agential realism and posthumanist performativity, and as such it accounts for human and nonhuman entanglements through which AD is performed in the lab in relational ways. In other words, the thesis explores how AD is enacted in the bodies of transgenic fruit flies (Drosophila melanogaster), as these flies embody the disease, live and die with it. Last but not least, the thesis explores the materialities of death, dying, embodiment and biological waste in a biochemistry lab as constitutive parts of the produced knowledge about AD. / Denna avhandling utgör ett bidrag till feministiska laboratoriestudier och är en kritisk analys av naturvetenskaperna. Närmare bestämt är det en feministisk studie av forskning om Alzheimers sjukdom, dess biokemiska verkningar och dödliga relationer utifrån ett års fältarbete som labbtekniker i ett fluglabb. Naturvetenskaperna har under decennier fascinerat genusforskare. Dessa discipliner formar kunskapen om vad som räknas som natur och naturligt, hälsa och sjukdom, normalt eller inte, och de har gjort så med stor samhällelig auktoritet genom Europeisk modernitet. Forskare inom feministiska teknovetenskapliga studier har länge hävdat att vetenskap också är social praktik med politiska implikationer. Begrepp som natur, djur, mänskligt eller kropp, kön och livet självt kan inte tas för givna utan formas också i laboratoriets naturkultur. Med utgångspunkt i sådana feministiska teknovetenskaplig teoribildningar och metodologiska utgångspunkter bearbetar denna avhandling frågor om hur vetenskapliga fakta om Alzheimers sjukdom skapas i laboratoriet idag. Vilka kroppar, verkligheter och etisk-politiska förhållningssätt aktualiseras? Vem får leva och vem får dö i vardagliga laboratoriepraktiker? Teoretiskt bygger avhandlingen framför allt på Karen Barads agentiella realism när den diskuterar sammanvävningen mellan mänskligt och icke-mänskligt, samt det som kallas posthumanistisk performativitet, i relation till Alzheimers sjukdom som den förkroppsligas i transgena fruktflugor (Drosophila melanogaster) i laboratoriet. I särskilt fokus står relationerna som skapas inom den biokemiska forskningen kring död, biologiskt avfall och kroppslighet.