This study quantifies the rate of bed bug nymphal development, mortality, fecundity and survivorship during starvation for wild caught resistant populations. I then compare some of these characteristics with two susceptible strains. I found that resistant populations develop faster and exhibit less mortality per life stage than susceptible populations. However, there were no significant differences in the total number of eggs produced by the resistant females from the field strains during the 13 feedings/oviposistion cycles (P = 0.106). On average, resistant females from the field strains produced 0.74 eggs per day. Susceptible strains survived a significantly longer time without feeding (89.2 d and 81.4 d) than the resistant strains (RR, ER). The mean duration of adult life (from the day the female becomes an adult until the day she dies) for (RR) strains was 118.7 d ° 11.8 SE. The intrinsic rate of increase r or average daily output of daughter eggs by female was 0.42. The net reproductive rate Rₒ, indicated that one live female egg would, on the average, be replaced by approximately 35 females. Resistant and susceptible populations were found to be different in terms of development, survivorship, and fecundity. The differences between susceptible and resistant strains could be explained by a trade-off between the alleles that confer resistance and the fitness in the population. When compare the stable age distribution of a pyrethroid susceptible strain (HS) and a resistant strain (RR) there were not significant differences (?°= 9.0066, df = 6, P = 0.1732) in the stable age distribution, basically both strains were dominated by the egg stage. No significant difference was found in the expected reproductive contribution of the various life stages to future population size between the two strains (?°= 1.5458, df = 6, P = 0.9564). Despite this, the reproductive contributions of life stages other than eggs were generally higher for the HS strain than for the RR strain. For both strains changes in P? for the adult stage are expected to have the greatest impact on?? compared with changes in P? for the other life stages. The key to the reduction of the populations of bed bugs lies with the reduction of survival of the adults. / Master of Science in Life Sciences

This study attempts to elucidate bed bug behavior in response to host cues and aggregation cues from conspecifics. Both fed and unfed bed bugs were evaluated to determine differences in behavior with regard to their circadian activities. Arena bioassays were conducted to determine the bed bug's ability to locate a host from different distances and if the antennae were essential for host location. Starved bed bugs were able to locate a host from 100 cm away. The bed bugs search path became more directed towards the host as the bed bug was placed at closer distances. The bed bugs' mean searching speed was found to be 1.7 cm/s. The bed bugs were able to locate a host even when their antennae were completely removed. Fed and unfed bed bugs were tested both individually and in groups to determine their attraction towards aggregation cues. Both fed and unfed bed bugs, regardless of sex, were significantly attracted to feces of conspecifics and exuvia of fifth instars. Finally, bed bugs were observed throughout the night to document their circadian activities after successfully taking a blood meal or failing to take a blood meal. Unfed bed bugs continued to search for a host throughout the night until aggregating together 2 hours prior to photophase. Alternatively, fed bed bugs immediately aggregated together within 30 minutes of a bloodmeal. / Master of Science in Life Sciences

Pest insects cause great financial losses in the forest and food industry every year. To fight these pests industries have used insecticides, which are sometimes harmful to nature and humans. One potential way of avoiding insecticides is the use of integrated pest management based on insect communication, which would offer species-specific methods for protecting forest and food resources. Insects use chemicals known as semiochemicals for both intra- and interspecies communication. By learning how insects use these semio-chemicals to talk to each other we can eavesdrop and mimic their communication for our benefit. One research area dealing with these questions is chemical ecology, which is an interdisciplinary area as knowledge in chemistry and biology is required. Collaborations between groups within and outside of Sweden are essential in order to make progress in this field of research. This thesis presents the identification and synthesis of semiochemicals from several insect species, most of which are considered to be pests. Synthesised compounds have been sent to collaboration partners around Sweden and Europe for biological evaluations. Studies of the African butterfly, Bicyclus anynana, have unravelled particular biological phenomena that may aid in the understanding of the Bicyclus genus, though recognizing individual species variation is crucial. In 2008 the putative male sex pheromone of B. anynana was determined to consist of three compounds: hexadecanal, (Z)-9-tetradecenol and 6,10,14-trimethylpentadecan-2-ol, and the specific stereoisomer for 6,10,14-trimethylpentadecan-2-ol has been determined in this thesis. The ratio of 6,10,14-trimethylpentadecan-2-ol and the corresponding ketone were investigated for seventeen Bicyclus species (including B. anynana) that live in overlapping regions in Africa. The stereochemistry was determined for most of the species and may provide a way to chemically distinguish them. The orchid bees, Euglossa spp, are important pollinators of many orchids in Central America. Insight about pollination and conservation of endangered orchid species may be possible by gathering more information about the Euglossa genus. Males of the Euglossa genus have pouch-like structures on their hind legs where they store compounds collected from their surroundings. 6,10,14-Trimethyl-pentadecan-2-one is a common component of leg extracts from Euglossa imperialis, E. crassipunctata and E. allosticta, the specific stereochemistry of which has been determined in this thesis. Another, different compound was found in high amounts in E. viridissima and its structure has been elucidated; several synthetic pathways are under investigation to obtain the target compound. Bed bugs (Cimex lectularius and C. hemipterus) are an ectoparasite that feed on human blood, and the number of reported infestations of these parasites has increased considerably during the last decade. Two 5th instar nymph-specific compounds, 4-oxo-hexenal and 4-oxo-octenal, were identified and synthesised. Utilizing domestic dogs (Canis lupus familiaris) in the identification of bed bug infestations has become popular during recent years. Their training is usually conducted using live bed bugs, however this thesis describes an alternative method of teaching dogs to find infestations. This alternative method is based on synthetic compounds and dogs trained in this manner have achieved a high positive indication rate. Two species of the tiny, Acacia leaf-eating insect pests in Australia known as thrips, Kladothrips nicolsoni and K. rugosus, have been investigated by means of larval extracts and have been shown to contain large amount of (Z)-3-dodecenoic acid which was synthesised and tested in bioassays. Fruit flies are common pests on fruit in almost every private household. Even though fruit flies has been investigated extensively, their chemical communication has not been completely elucidated. (Z)-4-undecenal was identified as a compound emitted by females, it was synthesised in high stereoisomeric purity and evaluated in biological assays. / FORE

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.

<b>Structure of the thesis</b><p><p>The present work has been organized in two main parts: in the first one, the focus will be on the scientific and theoretical aspects of the evaporation process in presence of an inert gas flow while in the second all the technical aspects and more practical tests related to the real implementation of the micro-gravity experiment CIMEX-1 will be detailed. In any cases, the discussion will always start from the phenomenology observed considering that ” Nature is far more reach of any speculations.”<p><p><b>Part I: Evaporation in presence of inert gas</b> <p><p>In chapter 1, a detailed presentation of the experimental setups for the on-ground tests is given together with the presentation of the qualitative and quantitative results obtained. Actually, the main parameters that regulate such kind of experiments are the mass flow rate of inert gas, the total pressure of the cell and the geometrical shape and dimensions of the evaporating regions.<p>Consequently, the experiments aimed at covering the maximal possible combination of these three parameters with special attention to the variation of the inert gas flow and of the thickness of the evaporating liquid layer. More precisely, the liquid layer thickness was in the range 1.2 to 3.8 mm while the inert gas flow was set in the range 50 to 2500 ml/min. The pressure has been partially neglected as control parameter because its control was discovered not to be very reliable.<p>The visualization system used in all the experiments consisted in a opportunely calibrated infrared camera. It allowed for having a quantitative analysis of the temperature distribution at the interface of the evaporating liquid.<p>The infrared images also helped to follow the thermal history of the interface. In many cases, it has been possible to clearly observe the evolution of instability patterns at the interface that represent an original contribution to the understanding of such a kind of phenomena.<p>The physical and mathematical modeling of the observed phenomenology will be the subject of the chapter 2. One of the peculiar issue of the problem under consideration is that the thermal gradient normal to the interface is not directly imposed like in the usual Marangoni-Bénard experience, but is a result of the cooling of the interface due to the evaporation.<p>Moreover,the interface is subject to the shear stress of the inert gas flow and to the one due to the thermo-capillarity. Finally, the gas phase is to be considered as a mixture; this oblige to solve a diffusion problem in the gas phase. A physical model that takes into account the different aspects mentioned above is presented together with the governing equations and the appropriate boundary conditions.<p>Numerical issues involved in solving the model are also analyzed. Numerical results obtained are finally discussed and compared when possible with experimental results.<p><p><b>Part II: Preparation of the CIMEX-1 experiment on-board the International Space Station.</b><p><p>In chapter 3, we will describe the main platforms used to perform low-gravity experiments. They will be classified according to the low-gravity level and to the low-gravity interval duration that could be ensured for experiments. According to these criteria, the list of the low-gravity platforms will be as follows: Drop Towers with ≈ 4 sec. of micro-gravity, Parabolic Flights that can assure not more than ≈ 25 sec. Sounding Rockets with a low-gravity time of the order of several minutes depending on the rockets, Foton Capsules that assure for many days of high quality - i.e. without perturbations - low-gravity level and ,last but not least, the International Space Station where the low-gravity duration could be even of several weeks which is a sufficient time duration for the most part of the experiments.<p>The chapter 4 will be entirely devoted to the ITEL experiment that is the precursor and the core of the CIMEX-1. After a brief overview of the experiment that has been performed twice on-board sounding rockets of the MASER class, the experimental setups used both on-ground and in micro-gravity will be detailed.<p>The focus will be on the experimental results obtained on-ground during the preparatory tests and during the two sounding rocket flights with special attention to the first one. The analysis will be supported by the presentation of many results obtained in numerical simulations.<p>The two parabolic flight campaigns performed to test one of the key sub-systems of the CIMEX-1 setup are the subject of the chapter 5. The separating-condensing unit is mandatory for performing the experiment on-board the International Space Station because the limitations on the crew intervention oblige to have a closed loop experiment.<p>The goal of the two parabolic flights will be detailed together with the setup and the experimental scenario. The main results will be also shown and some considerations on the efficiency of the system will be presented.<p>It is worthy to stress that the results obtained during these parabolic flights have been determinant at the European Space Agency level to fly the CIMEX-1 experiment on-board the International Space Station.<p>Finally, in the section conclusions and perspectives the main results obtained will be summarized together with the new scenarios opened by the present work and some guidelines for further development in the experimental, theoretical and technical analysis. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

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>

Although bed bug eggs are a difficult life stage to control with our currently labeled insecticides, few studies have examined how bed bug egg morphology and physiology is potentially related to pesticide resistance in bed bug eggs. Bed bug egg morphological features were examined using scanning electron microscopy (SEM) and the chorion and respiration structures were identified. Scanning electron microscopy photographs and bed bug egg measurements indicated there were no morphological differences between different bed bug egg strains (susceptible and resistant). Bed bug egg respiration rates measured by the amount of oxygen consumed (standard metabolic rate; SMR) also indicated there was no difference in SMR between different bed bug egg strains. Water conservation during respiration is vital to terrestrial insects. Therefore, similar patterns would be expected between egg water loss and respiration rates. However, susceptible strain eggs lost more water than one resistant strain of bed bug eggs, which was dissimilar from the respiration results, indicating that bed bug egg water loss and respiration are not directly related. Dose- response bioassays using two insecticide formulations (Temprid; imidacloprid/β-cyfluthrin, and Transport; acetamiprid/bifenthrin) indicated that bed bug eggs collected from pyrethroid resistant adult bed bug strains are also highly resistant. RNA sequencing of bed bug eggs from two resistant strains indicated that egg resistance may be directly related to the overexpression of multiple genes associated with insecticide resistance. / Master of Science in Life Sciences

The Common bed bug, Cimex lectularius L., suddenly reappeared in developed countries in the past 15 years. The factor contributing to the sudden resurgence of the bed bugs is insecticide resistance. In this study, we investigated the mechanisms of reduced cuticular penetration type insecticide resistance in bed bugs. First, we determined and compared the lethal dosage (LD50) of a pyrethroid insecticide using topical and injection application. The resistant strain not only had significantly greater resistance ratios, but also demonstrated significantly greater penetration resistance ratios. This provided the evidence of the reduced cuticular penetration in bed bugs. Second, we determined the levels of gene transcription (CPR-type cuticle protein genes) using real-time quantitative polymerase chain reaction (qRT-PCR). We identified 62 putative bed bug cuticle protein-encoding contigs based on the presence of the Chitin-binding 4 (CB4) domain. Based on the qRT-PCR analysis of the mRNAs, we found many of the genes were up-regulated in the resistant strain suggesting thickening of the cuticle or increasing the cuticular proteins might be involved in the reduced cuticular penetration. Third, we identified and described the cuticular proteins using the matrix-assisted laser desorption/ionization (MALDI) time-of-flight/time-of-flight (TOF/TOF) high-resolution tandem mass spectrometry (MALDI-TOF/TOF). The total of 265 peptides were identified, among which 206 belonged to one of 50 confidently identified proteins. We identified the CPRL, CPF, CPFL, TWDL, and CPAP1 family proteins. The profile of the cuticular proteins between the resistant and the susceptible strains bed bugs were almost identical. Fourth, we determined and compared the cuticular thickness using Scanning Electron Microscopy (SEM). We found statistical differences of the cuticular thickness among different strains (populations), however, correlation between the levels of insecticide resistance and cuticular thickness were not found. Finally, we identified and described bed bug cuticular hydrocarbon profiles using Gas-Chromatography and Mass-Spectrometry (GC-MS). The total of 87 compounds in addition to n-alkanes were extracted and identified. There were no correlation found with the concentration and the levels of insecticide resistance. However, several additional compounds exhibited the correlation between the concentration of the compounds and the levels of insecticide resistance. Overall, we found three lines of evidence to support reduced cuticular penetration as a mechanism of insecticide resistance in some bed bug populations. This study provides additional evidence of the reduced cuticular penetration type resistance in bed bugs. / Ph. D.