Ce travail s’articule sur trois axes ; le premier est une contribution à l'étude du répertoire des bactéries associées aux arthropodes vecteurs (tique et puces) en Afrique du nord (Algérie) et en Afrique Sub-saharienne (Bénin, Tanzanie et République Démocratique du Congo). Nous avons pu ainsi détecter par biologie moléculaire (qPCRs, PCR standard et séquençage) et pour la première fois au Bénin, Rickettsia typhi (l'agent du typhus murin), et Bartonella sp dans des puces collectées sur des rongeurs à Cotonou. Dans ce travail, nous avons également détecté Yersinia pestis, l'agent de la peste et R. felis (responsable de la fièvre boutonneuse) dans des puces de la RD du Congo. En Tanzanie, nous avons mis en évidence la présence de R. felis et R. typhi dans des puces de rongeurs. En Algérie, nous avons décrit pour la première fois la présence d'agent de borréliose de Lyme (Borrelia garinii) dans les tiques. Nous avons confirmé la présence de R. massiliae, R. monacensis R. aeschlimannii, R. slovaca et R. felis et nous avons également détecté pour la première fois en Algérie, Bartonella tamiae, une bactérie dont la pathogénicité est peu connue et Coxiella burnetii, l'agent de la fièvre Q.Dans la deuxième partie de notre travail, nous nous sommes intéressés à l’évaluation des compétences vectorielles des puces de chat (Ctenocephalides felis) et punaises de lit (Cimex lectularius) dans la transmission de l’agent de la fièvre des tranchées (Bartonella quintana) dont le vecteur connu est le pou de corps. Trois approches ont été utilisées : la qPCR, la culture et l’immunohistochimie. / This work focuses on three areas; the first is a contribution to the study of the repertoire of bacteria associated with arthropod vectors (tick and flea) in North Africa (Algeria) and in Sub-Saharan Africa (Benin, Tanzania and the Democratic Republic of Congo). We could thus detected by molecular tools (qPCRs, standard PCR and sequencing) and for the first time in Benin, Rickettsia typhi (the agent of murine typhus) and Bartonella sp in fleas collected from rodents in Cotonou. In this work, we have also associated the agent of plague (Yersinia pestis), and for the first time in fleas of DR of Congo, and we detected also R. felis (the causative agent of spotted fever). In Tanzania, we have highlighted the presence of R. typhi and R. felis fleas on rodents. In Algeria, we described for the first time the presence of Lyme disease agent (Borrelia garinii) in hard ticks. We confirmed the presence of R. massiliae, R. monacensis, R. aeschlimannii, R. slovaca and R. felis, we also detected for the first time Bartonella tamiae and Coxiella burnetii associated with bat ticks in Algeria.Regarding the second part we was interested in the evaluation of vector competence of cat fleas (Ctenocephalides felis) and bed bugs (Cimex lectularius) in the transmission of trench fever agent (Bartonella quintana) that is known to be transmitted by lice. Three approaches have been tested; qPCR, culture and immunohistochemistry.

The focus of this dissertation is on bed bug thermal biology. How bed bugs react to heat exposure at the population, behavioral, and physiological levels was explored. The thermal tolerance of different bed bug populations and sublethal effects heat exposure were investigated. The temperatures that cause bed bugs to flee from their harborages was determined using a custom made arena. How bed bug physiology changes after heat exposure was determined using RT-qPCR. Finally, how conspecifics react to bed bugs that have been lethally exposed to heat was determined using still air bioassays.<br>

The present thesis deals with the phenomenon of additional sex chromosomes in Cimex lectularius (Hemiptera: Heteroptera: Cimicidae) using genome size analysis combined with the classical cytogenetic approach. Also, five other cimicid species and 12 species from the family Nabidae were analysed identically for comparative purposes. The thesis also pursues a description of methodical approaches of cytogenetics and flow cytometry in the study of C. lectularius. Recently analysed European specimens of C. lectularius from human host exhibited 12 distinct cytotypes, with a variable number of chromosomes X from two to 20 (2n♂ = 26+X1X2Y to 26+X1-20+Y). The fragmentation hypothesis of C. lectularius additional chromosomes X origin was established in the second half of the 20th century. However, the present genome size measurements suggest that various chromosomal rearrangements as duplication or deletion besides the fragmentation could occur. Males with basic cytotype 2n = 26+X1X2Y had average genome size of 2C = 1.94 pg, in contrast male with 2n = 26+X1-7+Y yielded 2C = 2.26 pg and also specimens with genome size decrease 2C = 1.69 pg appeared. The most informative turned up to be the relative genome size of sperm cells n = 13+X1X2 and n = 13+Y, where specimens with higher chromosome number showed...

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.

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.

Bed bugs (Hemiptera:Cimicidae) are a common, hematophagous ectoparasite of humans and other animals, and are experiencing an international resurgence. Cimicids have been implicated in the transmission many disease agents, including various Bartonella species, however disease transmission has not yet been confirmed. Bartonella spp. are transmitted by a variety of arthropods, including fleas, lice and sand flies, and it is speculated that bed bugs may also serve as a potential vector. In this study, we used an artificial membrane to feed two groups of adult Cimex lectularius rabbit blood, either infected or uninfected with Bartonella henselae. After two weeks, the presence of Bartonella henselae was assessed via PCR, and salivary glands from infected and uninfected bed bugs were dissected and processed for transmission electron microscopy. We were unable to visually identify Bartonella henselae in the images, and therefore unable to confirm the role of bed bugs in B. henselae transmission.

<p>Bed bugs (<i>Cimex lectularius</i> L.) are globally important human ectoparasites. Their management necessitates the use of multiple control techniques. Plant-derived essential oils are extracts from aromatic plants that represent one of the alternative control measures for bed bug control, in addition to mechanical options and synthetic pesticides. However, there is limited information available on the efficacy and toxicology of plant essential oils against bed bugs. This project was designed with the aim to provide in-depth information on efficacy, toxicology and mode-of-action of essential oils and their insecticidal constituents in bed bugs. Initially, I evaluated topical and fumigant toxicity of fifteen essential oil components against adult male bed bugs of the Harlan strain (an insecticide susceptible strain). Neurological effects of the six most toxicologically active compounds were also determined. In both topical and fumigant bioassays, carvacrol and thymol were the most active compounds. Spontaneous electrical activity measurements of the bed bug nervous system demonstrated neuroinhibitory effects of carvacrol, thymol and eugenol, whereas linalool and bifenthrin (a pyrethroid class insecticide) produced excitatory effects. Further, I evaluated the efficacy and neurological impacts of a mixture of three neuroinhibitory compounds; carvacrol, eugenol and thymol in 1:1:1 ratio against adult male bed bugs of the Harlan strain. This mixture of monoterpenoids as well as the mixture of synthetic insecticides exhibited a synergistic affect in topical bioassays. In electrophysiology experiments, the monoterpenoid mixture led to higher neuroinhibitory effects, whereas a mixture of synthetic insecticides caused higher neuroexcitatory effects in comparison to single compounds. </p> <p>In the next objective of my dissertation, I compared the efficacy of five plant essential oils (thyme, oregano, clove, geranium and coriander), their major components (thymol, carvacrol, eugenol, geraniol and linalool) and EcoRaider^® (commercial product) between pyrethroid susceptible (Harlan) and field collected (Knoxville) bed bug populations. Initially, I found that the Knoxville strain was 72,893 and 291,626 fold resistant to topically applied deltamethrin (a pyrethroid class insecticide) compared to the susceptible Harlan strain at the LD₂₅ and LD₅₀ lethal dose levels, respectively. Synergist bioassays and detoxification enzyme assays showed that the Knoxville strain possesses significantly higher activity of cytochrome P450 and esterase enzymes. Further, Sanger sequencing revealed the presence of the L925I mutation in the voltage gated sodium channel gene. The Knoxville strain, however, did not show any resistance to plant essential oils, their major components or EcoRaider^® in topical bioassays (resistance ratios of ~ 1). In the final objective, I evaluated the efficacy of binary mixtures of above-mentioned essential oils or their major components or EcoRaider^® with deltamethrin in susceptible and resistant bed bugs. In topical application bioassays, binary mixtures of essential oils or their major components or EcoRaider^® and deltamethrin at the LD₂₅ dose caused a synergistic increase in toxicity in resistant bed bugs. Further, I studied the inhibitory effects of major essential oil components on detoxification enzyme activities (cytochrome P450s, esterases and glutathione transferases). Detoxification enzyme assays conducted using protein extracts from bed bugs pre-treated with essential oil constituents showed that these compounds significantly inhibited cytochrome P450 activity in the resistant strain, but esterase and glutathione transferase activity were unaffected. No inhibition of detoxification enzyme activities was observed in the Harlan strain bed bugs pre-treated with essential oil constituents.</p> <p>In conclusion, my dissertation research has created the foundation for utilization of natural products for bed bug management by (i) describing the efficacy of plant essential oils and their components against bed bugs, (ii) discovering synergistic interactions between essential oil components at the nervous system level, (iii) determining susceptibility of deltamethrin-resistant bed bugs to plant essential oils and their constituents and (iv) identifying synergistic effects of essential oils or their components on toxicity of pyrethroid insecticides and underlying mechanisms of this synergistic interaction. </p> <br>