This thesis was developed in order to determine whether the selected species most commonly kept feeding insects affect fertility in captive bred assassin bugs \kur{Platymeris biguttatus}. Used feeding insects were \kur{Blaptica dubia} roaches, \kur{Acheta domestica} crickets and larvae of \kur{Tenebrio molitor} bugs. The reason of using assassin bugs \kur{Platymeris biguttatus} was their popularity among breeders, their easy care needs and their superior fertility. Assassin bugs were kept in an air conditioned room with a constant temperature conditions and light regime. It has been shown that the given diet has no effect on fertility in this kind of bugs, also that breeding in groups has negative impact on fertility of this assassin bugs species. The results of this study could demonstrate the importance of proper feeding in keeping these bugs and help breeders to have better results.

Experiments based on the method of mark-recapture can be used for estimation of the abundance of natural populations, for monitoring dispersion of groups or individual specimens within a population using group or individual marking. Semiaquatic bugs (Heteroptera: Gerromorpha) were marked and recaptured many times in the field during research, individual marking was much less used since marking of small insects is difficult. The aim of this work is to develop a method of individual marking of semiaquatic bugs so that it would meet conditions such as durability, legibility and non affecting health of the marked specimen. Semiaquatic bugs of Aquarius paludum, Gerris lacustris, Limnoporus rufoscutellatus (Gerridae) and Velia caprai (Veliidae) species were selected as experimental organisms. Partial aims of this thesis were to try using this method to describe the abundance of the monitored population and to monitor dispersion of the selected species, both at lotic (V. caprai) and lentic habitats (water striders, family Gerridae). A new method of individual marking of semiaquatic bugs was developed on the basis of modifications of the commonly used methods. After a series of tests and in-field research, this method proved to be suitable as it met the essential conditions for marking insects. The abundance of the monitored population was estimated and dispersion of the selected species (V. caprai) in running water was described by using this method. The partial aims of this thesis were met, too. It was confirmed that individuals of the V. caprai species move between the monitored areas along the water course. This inclination to move is greater than tendency to remain in the place of release. The gained data also show conclusively higher rate of movement of V. caprai specimens in the upstream direction, compared to the downstream. The tendency of V. caprai to travel larger distance upstream than downstream, is significant too. No statistically relevant difference in either direction of the water course (up or down) in the surpassed altitude difference was confirmed. The differences in the monitored phenomena between the sexes and generations were compared as well. The differences, however, were not significant. A movement of the adults of the water cricket Velia caprai thus can be characterized as an upstream migration, common in insects of lotic habtitats. A part of the study taking place in still waters showed, that G. lacustris specimens move on the surface of the pond, but not to a larger degree than they remain in place. On the other hand, A. paludum specimens were proved to move away from the place of release rather than remaining in that place. These also overcome greater distance than G. lacustris specimens.

The Human Chagas disease still affects a great number of people around the world, and the Northeast of Brazil has attracted the attention of public health authorities, due to the presence of native insects and dwellings of poor quality, prone to colonization of triatomines responsible for transmission of this disease. Aiming to check the infection rate of triatomines and research the human infection with Trypanosoma cruzi in a rural area of Tobias Barreto in the southern state of Sergipe, was developed a study with two model approaches. Initially retrospective data were collected at the Laboratório Central de Sergipe to identify the species and the infection rate of triatomines with Trypanosoma cruzi in this municipality. The species found were: Triatoma pseudomaculata, Triatoma tibiamaculata, Triatoma melanocephala, Panstrongylus megistus, Panstrongylus lutzi and Panstrongylus geniculates. It was observed a wide variation in the rate of infection in different species - 31.2 to 100.0% (from 2006 to 2011). Proceeded with a cross-sectional study involving 235 individuals, aged 1-30 years old, in the villages of Alagoinhas and Poço da Clara. We collected blood samples from 235 individuals of this population. These samples were submitted to serological tests for Chagas Disease (ELISA and indirect immunofluorescence), but did not identify the disease in the population studied. It is possible that this seronegativity is result of factors such as young age (under 30 years), vector-parasite interaction (with lower rates of metacyclogenesis) or the influence of host genetics in susceptibility to infection. It wasn´t detected human infection in the population aged 1-30 years old, despite high infection rate of triatomines with Trypanosoma cruzi in the region, suggesting no recent transmission of the Chagas Disease. / A Doença de Chagas Humana ainda atinge um grande número de pessoas em todo o mundo, sendo que a região Nordeste do Brasil tem despertado atenção das autoridades em saúde pública, devido à presença de triatomíneos autóctones e moradias de baixa qualidade, propícias à colonização de triatomíneos transmissores desta doença. Com o objetivo de verificar a taxa de infecção triatomínica e a pesquisa de infecção humana por Trypanosoma cruzi em uma área rural de Tobias Barreto, sul do Estado de Sergipe, foi realizado um estudo com dois modelos de abordagem. Inicialmente foram coletados dados retrospectivos no Laboratório Central de Sergipe para identificar as espécies e a taxa de infecção dos triatomíneos por Trypanosoma cruzi neste município. As espécies encontradas foram: Triatoma pseudomaculata, Triatoma tibiamaculata, Triatoma melanocephala, Panstrongylus megistus, Panstrongylus lutzi e Panstrongylus geniculates. Foi encontrada grande variação na taxa de infecção nas diferentes espécies - 31,2 a 100,0% (no período de 2006 a 2011). Prosseguiu-se com a realização de estudo transversal, envolvendo 235 indivíduos, com idades entre 1 a 30 anos, nos povoados Alagoinhas e Poço da Clara. Foram coletadas amostras de sangue dos 235 indivíduos desta população. Estas amostras foram submetidas aos testes sorológicos para Doença de Chagas (ELISA e Imunofluorescência Indireta), contudo, não se identificou a infecção na população estudada. É possível que essa soronegatividade seja resultado de fatores como: faixa etária jovem (menor de 30 anos), interação parasito-vetor (menores taxas de metaciclogênese) ou a influência das características genéticas do hospedeiro na susceptibilidade à infecção. Não foi detectada a infecção humana na população entre 1 a 30 anos de idade, apesar da elevada taxa de infecção dos triatomíneos pelo Trypanosoma cruzi na região, sugerindo não haver transmissão recente da doença.

Une des 17 maladies tropicales négligées déclarées par l’OMS, l’ulcère de Buruli constitue aujourd’hui un réel problème de santé publique en Afrique centrale et de l’Ouest où il sévit dans près de 30 pays. Cette maladie touchant principalement les populations des zones enclavées reste un mythe car l’on ne connaît pas aujourd’hui le mode de transmission exacte de la bactérie responsable, Mycobacterium ulcerans, à l’humain. Une meilleure connaissance de l’écologie de ce bacille constitue pourtant un levier important tant pour apporter des informations concernant sa transmission que pour lutter contre ce fléau. Fortement soupçonnés de jouer un rôle d’hôtes ou de vecteur de M. ulcerans, certains taxons de punaises aquatiques semblent être prédisposés de par leur écologie ou leur comportement à héberger le bacille voire à le transmettre. Les travaux que nous présentons ici visent dans un premier temps à identifier sur des bases anatomiques complétées par des approches moléculaires les différents taxons de punaises aquatiques présents au Cameroun. Au-delà de proposer une clé d’identification d’espèces et une classification des punaises aquatiques du Cameroun reposant sur des séquences nucléotidiques, nous discutons du rôle important joué par l’écologie de certaines espèces de punaises dans la transmission de M. ulcerans. Les différentes approches comparatives et biostatistiques développées dans ce travail de thèse étayent l’hypothèse que certains taxons de punaises aquatiques, et notamment issus des familles Belostomatidae et Naucoridae, acquièrent la mycobactérie à partir de l’environnement en partageant des habitats (fréquentation de la végétation aquatique émergée) où le bacille prolifère, et en se nourrissant de proies, comme des mollusques ou de petits poissons, eux-mêmes contaminés par la bactérie. La capacité de vol chez les punaises aquatiques n’apparaît pas faciliter l’acquisition de M. ulcerans mais semble impliquée dans la dissémination de ce dernier en contaminant de nouveaux environnements. Au terme de cette thèse, nous discutons de l’écologie des communautés de punaises aquatiques et de leur macroécologie au Cameroun, et examinons l’importance de l’échantillonnage comme élément important de tout travail de recherche en écologie et évolution des maladies infectieuses. / One of 17 neglected tropical diseases declared by WHO, Buruli ulcer is now a real public health problem in Central and West Africa, where it occurs in nearly 30 countries. This disease mainly affecting people in remote areas remains a myth because we don't know today the exact mode of Mycobacterium ulcerans transmission, the causal agent to humans. A better understanding of the ecology of this bacillus is an important lever to make the information about its transmission as the fight against this scourge. Strongly suspected to playing a role of host or vector of M. ulcerans, some aquatic bugs’ taxa seem to be predisposed by their ecology or behavior to harbor the bacillus or to convey it. The works presented here are intended firstly to identify on anatomical bases complemented by molecular approaches different taxa of aquatic bugs present in Cameroon. Beyond proposing an identification key of taxa and classification of aquatic bugs in Cameroon based on the nucleotide sequences, we discuss the important role of the ecology of some taxa of aquatic bugs in the transmission of M. ulcerans. Different comparative and biostatistics approaches developed in this thesis support the hypothesis that some taxa of water bugs, especially from the Belostomatidae and Naucoridae families acquire the mycobacteria from the environment by sharing habitats (attendance of emerged aquatic vegetation) where the bacilli proliferate, and feeding on prey such as molluscs and small fish themselves contaminated with the bacteria. The flight capacity of aquatic bugs do not appear to facilitate the acquisition of M. ulcerans but seems to be involved in their dissemination by contaminating new the environments. At the end of this thesis, we discuss the ecology of aquatic bugs’ communities and their macroecology in Cameroon, and examine the importance of sampling as an important component of any research work in ecology and evolution of infectious diseases.

According to chapter 5, section 3 of the Swedish School Law (2010: 800), it is written that "The education should be designed in such a way that all pupils are assured of a school environment characterized by safety and education". Today's school students are our future and it is therefore important to analyze puplis’ safety at school. This study investigates whether there is variation between schools, between municipalities and between schools within municipalities in Östergötland regarding pupils' safety at school. This study also investigates which variables that can affect school safety. The reason for this study is to provide a basis for further work to improve puplis’ school safety. The study is based on survey responses from the survey Om mig, which was sent to secondary grade in elementary school and grade 2 in upper secondary school. Data is divided into three parts, where respondents from primary school are in one, respondents from upper secondary school in one and finally one data for the whole of Östergötland, which contains both respondents for elementary school and upper secondary school. The response variable is the question How often do you feel safe at school?, Where students could answer, Always, Often, Sometimes, Rarely or Never. The explanatory variables are variables related to the school and to the student's health, such as trustworthy friend, bullying, stress, support and help developing. In Bilaga1, all of the variables examined are described. This study uses a multilevel logistic regression. Parameters are estimated using Bayesian inferences with noninformative prior distributions. The response variable is converted to a binary variable, where Always and Often was merged, and Sometimes, Rarely and Never was merged. The result showed that there is a small variation in puplis’ safety at school between schools, between municipalities and between schools within municipalities for primary school, upper secondary school and the whole of Östergötland. It was also investigated which variables affect school safety, it proved to be very similar between elementary school and upper secondary school, including bullying, how often students experience good mood at school, and if the students feel that they are treated equally by the teachers have an effect on the puplis’ safety at school. / Enligt 5 kapitlet 3 § i skollagen (2010:800) står det skrivet att ”Utbildningen ska utformas på ett sådant sätt att alla elever tillförsäkras en skolmiljö som präglas av trygghet och studiero”. Dagens skolelever är vår framtid och det är därför viktigt att analysera elevers trygghet i skolan. Denna studie undersöker om det finns variation mellan skolor, mellan kommuner samt mellan skolor inom kommuner i Östergötland vad gäller elevers trygghet i skolan. Studien undersöker även vilka variabler som kan ha effekt på tryggheten i skolan. Anledning till att denna studie genomförs är för att ha ett underlag i fortsatt arbete för att förbättra tryggheten i skolan. Studien bygger på enkätsvar från enkäten Om mig, som skickas ut till årskurs 8 i grundskolan samt årskurs 2 på gymnasiet. Datamaterialet är uppdelat i tre delar, där respondenter från grundskolan finns i ett, respondenter från gymnasiet i ett och till sist ett datamaterial för hela Östergötland som innehåller båderespondenter från grundskolan och gymnasieskolan. Responsvariabeln är frågan Hur ofta känner du dig trygg i skolan?, där eleverna kunde svara, Alltid, Ofta, Ibland, Sällan eller Aldrig. Förklaringsvariablerna är variabler som är relaterade till skolan och till elevens hälsa, till exempelpålitlig vän, mobbning, stress, stöd och hjälp att utvecklas. I bilaga 1 finns samtliga undersökta variabler beskrivna. Studien använder sig av en logistisk regression med flera nivåer. Parametrarna skattas med hjälp av Bayesiansk inferens med icke-informativa priorfördelningar. Responsvariabeln kodas om till en binärvariabel, där Alltid och Ofta slås ihop samt Ibland, Sällan och Aldrig slås ihop. Resultatet visade att det finns en liten variation i trygghet mellan skolor, mellan kommuner och mellan skolor inom kommuner, för grundskolan, gymnasiet och för hela Östergötland. Det undersökts även vilka variabler som har effekt på tryggheten i skolan, det visade sig vara väldigt lika mellan grundskolan och gymnasiet där bland annat mobbning, hur ofta eleverna upplever bra stämning i skolan samt om eleverna upplever att de blir rättvist behandlade av lärarna har en effekt på tryggheten i skolan.

The introductory part of this thesis sums up the state of knowledge on aposematism and mimicry, the effect of aposematic and mimetic signals on spider predators, and cases when spiders do not receive but send such signals. Attachments of the thesis include four original manuscripts. In the first study, we presented jumping spiders (Evarcha arcuata, Salticidae) with different colour forms (red-and-black, yellow-and-black, white-and-black) of the firebug (Pyrrhocoris apterus, Pyrrhocoridae). Our goal was to compare reactions of the spiders to various intensity of aposematic signalization, expecting red-and-black coloration to have the strongest effect. Aversive learning of all colour forms was equally effective, but generalization of the learned avoidance to other colour forms was more effective after switch from less (white-and-black, yellow-and-black) to more (red-and-black) conspicuously coloured prey. When tested the next day, avoidance of the white-and-black prey got mostly forgotten. In the second study, we assessed little studied sensitivity of spiders to smells of unpalatable prey. After jumping spiders learned to avoid firebugs, most of them avoided the firebug smell, showing their sensitivity not only to optical, but also to chemical part of signalization of the unpalatable prey. In the...

Sexual conflict occurs when the reproductive optima of males and females are at odds with one another. Conflict between the sexes is ubiquitous across the animal kingdom and is expected to influence the social dynamics of group-living animals. Yet, most social behaviour studies do not address the potential ramifications that sexual conflict can have on social interactions. For my thesis, I used bed bugs (Cimex lectularius) to bridge the gap between sexual conflict and social behaviour. In Chapter 1, I developed a novel semi-naturalistic arena for tracking bed bugs to uncover how sexual conflict shapes animal social networks. My results show that male and females can be in conflict over the social environment. In Chapter 2, I examined how female sexual history shapes mating interactions using bed bugs. First, I showed that realistically high rates of traumatic insemination relative to lower rates dramatically reduce female fitness. Next, I manipulated female insemination status in a realistic group setting and found that males can exhibit strong mate choice even in a mating system with seemingly little male reproductive investment. Lastly, I tracked avoidance behaviour exhibited by female bed bugs as they received successive inseminations and demonstrated that female bed bugs possess plastic avoidance strategies based on their mating history. In Chapter 3, I examined how social experience shapes sexual interactions in a complex, competitive environment and found that social experience did not improve male or female bed bugs’ sexual competence. Finally, in Chapter 4, I extended my work on polyandry to fruit flies (Drosophila melanogaster) and showed that realistically high rates of female multiple mating can increase female fitness. In each chapter, I discuss the significance of my findings as they relate to sexual selection and the evolution of social and sexual strategies and behaviours in both sexes. / Dissertation / Doctor of Philosophy (PhD) / Sexual conflict occurs when the reproductive interests of males and females are not in alignment with one another. A common form of sexual conflict occurs when males want to mate more often than females, resulting in harassment of females. Such conflict between the sexes over mating is common across the animal kingdom. While there are many evolutionary consequences of sexual conflict, little is known about how sexual conflict influences the social behaviours of animals. For my thesis, I used bed bugs (Cimex lectularius) to bridge the gap between sexual conflict and social behaviour. I showed that bed bugs are under intense sexual conflict over mating rates which influences both females’ social preferences and their behavioural responses to males. I also found that bed bug females often mate with multiple males, which plays a large role in male mating behaviours and strategies. Finally, using fruit flies (Drosophila melanogaster), I show that mating with multiple males can sometimes be highly beneficial to females. The results of my studies have important implications for understanding the evolution of social and sexual behaviours in both sexes.

Na cultura da soja ocorre um grupo de percevejos sugadores de sementes, Euschistus heros (E.), Piezodorus guildinii (West.) e Nezara viridula (L.), que causam diversos distúrbios fisiológicos durante o cultivo, como o atraso da maturidade fisiológica, a retenção foliar, as perdas na produtividade e a redução do potencial fisiológico das sementes. A reação dos genótipos de soja ao estresse por percevejos é uma abordagem importante durante a etapa de melhoramento, produção de sementes e desenvolvimento de novas linhagens de soja resistente. O objetivo deste estudo foi comparar os parâmetros de produção e qualidade das sementes, e a resposta de defesa da planta dos diferentes genótipos de soja em condições de ataque de percevejos. Os ensaios foram conduzidos na Estação Experimental de Anhumas (Departamento da Genética, USP, ESALQ), com as populações de plantas de soja submetidas à condição de infestação natural dos percevejos nos anos agrícolas 2012/13 e 2013/2014, com plantas cultivadas sem o controle químico de percevejos e com o controle, em blocos casualizados com cinco repetições em cada sistema de controle. Análises dos dados foram feitas com ANOVA e MANOVA. No primeiro ano, vinte quatro genótipos de soja foram avaliados para os parâmetros agronômicos e de resistência da planta (período de formação de sementes (PFS), ciclo das plantas (Ciclo), altura da planta (AP), índice de acamamento (IA), valor agronômico (VA), número de vagem (NV), peso de mil sementes (PMS), produtividade (PROD), retenção foliar (RF) e peso de sementes boas (PSB)). No segundo ano com oito genótipos de soja, as plantas foram avaliadas pelos mesmos parâmetros agronômicos e de resistência do primeiro ano, exceto o NV e com o acréscimo da avaliação do índice percentual de danos nas vagens (IPDV) e as sementes quanto a qualidade fisiológica (germinação, envelhecimento acelerado, emergência, condutividade elétrica e tetrazólio). Além disso, as sementes e vagens de dois genótipos LQ1050 e CD215, coletadas entre os estágios R5 e R6, foram avaliadas quanto ao teor de isoflavonas em condições de estresse por percevejo no campo. Com o monitoramento da população de percevejos foi possível verificar um aumento de percevejos no PFS, sendo que a densidade populacional no ano agrícola 2012/13 foi mais alta. Para a seleção efetuada no primeiro ano agrícola 2012/13, considerou-se como principal critério o PSB mínimo e máximo para genótipos resistentes e suscetível ao percevejo para a avaliação da qualidade das sementes no segundo ano de cultivo 2013/14. Genótipos de soja com alta produtividade não garantem que os mesmos tenham resistência ao complexo de percevejos e produzam sementes com alta qualidade fisiológica. Foi verificada, nos oitos genótipos de soja do segundo ano de cultivo, variabilidade genética entre cultivares e linhagens de soja para características de qualidade fisiológica avaliada por meio dos testes de germinação e de vigor. Parâmetros utilizados para avaliação da qualidade fisiológica podem ser correlacionados com a resistência da planta ao complexo de percevejos. Coumestrol e gliocelina, compostos fitoalexinas, foram determinados nas vagens de genótipos contrastantes, mas não nas sementes. / A group of stink bugs composed by Euschistus heros (E.), Piezodorus guildinii (West.), and Nezara viridula (L.) causes several physiological disturbs in soybean during the field production, such as: delayed physiological maturity, leaf retention, yield loss, and decreased seed quality and germination potential. The reaction of soybean genotypes to stink bugs complex is an important approach for the crop breeding, seed production, and development of new resistant lines. This work aimed to compare the production and seed quality parameters, besides the plant defense under conditions of stink bugs attack. Assays were carried out at the Experimental Station of Anhumas (Department of Genetics, USP, ESALQ) with the soybean plants submitted to natural infestation by stink bugs, at 2012/13 and 2013/14 crop seasons, with absence and presence of chemical control of the insects, in a randomized block design with five replicates. The data were submitted to both ANOVA and MANOVA analysis. At the first season, 24 genotypes were evaluated as for the agronomic and plant resistance traits: seed formation period, plant life cycle, plant height, lodging index, agronomic value, number of pods per plant, mass of 1000 seeds, yield, foliar retention, and mass of healthy seeds. At the second season, eight genotypes were evaluated by the same agronomic and plant resistance traits of the first season, except the number of pods per plant. The pods damage index and seed physiological quality (germination, accelerated aging, emergence, electrical conductivity, and tetrazolium test) traits were evaluated only in the second season. The pods and seeds of LQ1050 and CD215 genotypes were collected between the R5 and R6 stages and had the isoflavones levels evaluated in conditions of stress by stink bugs attack. Through the monitoring of stink bugs population, it was possible to notice the increase of the insects in the seed formation period, with higher population density in the 2012/13 season. In the first season, the minimum and maximum masses of healthy seeds were taken as the main criterion to select susceptible and resistant genotypes, respectively, to the stink bugs attack, for the seed quality evaluation in the second season 2013/14. High yield genotypes do not ensure resistance to the stink bugs complex and, therefore, seeds with high physiological quality. We have noticed the genetic variability among the genotypes as for the physiological quality evaluated through the germination and vigor tests, at the second season. Traits used for the physiological quality can be correlated with the plant resistance to the stink bugs complex. Coumestrol and glyceollin, phytoalexin compounds, were identified in pods of the contrasting genotypes, but not in the seeds.

Percevejos de cama são insetos de importância em saúde pública pela sua hematofagia obrigatória em todos os estágios de vida em que se alimenta. Cimex lectularius é a espécie mais comum, cosmopolita e antropofílica. Apesar de não serem considerados vetores comprovados de patógenos, suas características biológicas podem torná-los potenciais vetores. Esses insetos residem próximo ao hospedeiro e geram grandes infestações. Desde a década de 1990, observa-se aumento nos relatos de infestações em diversas regiões do mundo. No Brasil a literatura sobre esta praga é muito escassa e a ocorrência de infestações não tem sido sistematicamente registradas. Objetivou-se neste estudo atualizar os conhecimentos sobre percevejos de cama, com enfoque na espécie Cimex lectularius e propor um Guia de Vigilância e Controle. Recorrendo-se a uma busca bibliográfica sobre percevejos de cama nas publicações de 1990 a 2017, atualizaram-se dados de sistemática, distribuição, morfologia, bioecologia, infestação e importância médica. Baseando-se em guias e manuais de vigilância de percevejos de cama de programas de vigilância operantes em outras cidades do mundo e em relatos de casos de infestações, foi elaborado o conteúdo para um Guia de Vigilância e Controle de percevejos de cama, a fim de nortear as ações dos órgãos de vigilância em saúde e subsidiar a instalação de um programa de vigilância entomológica desses insetos. / Bedbugs are insects of importance in public health due to their obligatory hematophagy in all stages of life in which they are fed. Cimex lectularius is the most common, cosmopolitan and anthropophilic species. Although they are not considered proven vectors of pathogens, their biological characteristics may make them potential vectors. These insects live near the host and generate large infestations. Since the 1990s, there has been an increase in reports of infestations in several regions of the world. In Brazil the literature on this pest is very scarce and the occurrence of infestations has not been systematically recorded. The objective of this study was to update the knowledge about bedbugs, focusing on the species Cimex lectularius and to propose a Guide for Surveillance and Control. Using a bibliographical search about bed bugs in the publications from 1990 to 2017, systematics, distribution, morphology, bioecology, infestation and medical importance data were updated. Based on guides and manuals for bedbug surveillance of surveillance programs operating in other cities around the world and in reports of cases of infestations, the contents of a Guide to Bedbug Surveillance and Control were developed in order to guide the actions of health surveillance agencies and subsidize the installation of an entomological surveillance program for these insects.

Entre os problemas envolvidos na produção de sementes de soja de alta qualidade destacam-se os causados por percevejos, os danos mecânicos e a deterioração por umidade, que resultam em perdas de germinação e de vigor. A técnica de análise de imagens (raios X) é um método de precisão que possibilita examinar, com detalhes, a região danificada ou alterada, sua localização e extensão. Por ser um método não destrutivo, as sementes em análise podem ser submetidas a testes fisiológicos e, desta forma, é possível estabelecer as relações de causa e efeito. Tendo em vista estes aspectos, o presente trabalho teve como objetivo utilizar a técnica de análise de imagens na identificação de danos em sementes de soja e avaliar sua eficiência comparando com os dados obtidos pelo teste de tetrazólio. Este trabalho foi conduzido nos Laboratórios de Análise de Imagens e de Análise de Sementes, do Departamento de Produção Vegetal, da Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, em Piracicaba, SP. Sementes de diferentes lotes de um mesmo cultivar (BRS 184) foram submetidas ao teste de raios X e, posteriormente, destinadas ao teste de primeira contagem de germinação, de forma a relacionar os danos com os possíveis prejuízos proporcionados às sementes. Paralelamente, foi realizado o teste de tetrazólio visando comparação com o teste de raios X. Para a análise interpretativa dos testes, foram consideradas a severidade e a localização dos danos. Com os resultados obtidos, pode-se afirmar que a análise de imagens mostrou-se eficiente na detecção dos danos mecânicos, por percevejos e por umidade, havendo correlação positiva com os resultados obtidos pelo teste de tetrazólio. / Image analysis is a very promising technique to determine damages in seeds, which can result in losses of germination and vigor. This precise method examines seeds individually by using enlarged images in which damaged areas, as well their exact location and extension, can be found and examined in details. This is a non-destructive method, so analyzed seeds can be submitted to physiological tests to establish the relationship between damage and quality loss. The goal of this research was to study the use of image analysis technique (X-ray) to identify chinch-bugs, mechanical and humidity damages in soybean seeds. The research was carried out at Image Analysis and Seed Analysis Laboratories from Crop Science Department, “Luiz de Queiroz” College of Agriculture, University of São Paulo, in Piracicaba, SP, Brazil. Seeds of different lots of soybean, cultivar BRS 184, were submitted to the X-ray test and, consecutively, used for the first count of the germination test, in order to determine the possible relationship between cause and effect. Simultaneously, X-ray test was compared with the tetrazolium test. For the interpretation of the X-ray test, the severity and location of chinch-bugs, mechanical and humidity damages were considered. The results showed that X-ray test is efficient to detect these damages in soybean seeds.