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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Comparison of the Mitochondrial Genomes of the Common Bed Bug (Cimex lectularius), Eastern Bat Bug (Cimex adjunctus), and Swallow Bug (Oeciacus vicarius)

2015 July 1900 (has links)
Species within the family Cimicidae (bed bugs) are hematophagous ectoparasites of mammals and birds. Many cimicids are of socio-economic importance. Despite the global resurgence of these pests, there is currently a paucity of information regarding the mitochondrial (mt) DNA sequences of cimicids. Therefore, I used a PCR-based primer walking strategy to amplify and sequence the near complete mitogenome of the common bed bug (Cimex lectularius), and several mitochondrial gene regions of the Eastern bat bug (Cimex adjunctus) and swallow bug (Oeciacus vicarius). I compared the mitochondrial genetic variability between C. lectularius from two populations to look for molecular markers useful for population genetic studies. Furthermore, the mt DNA sequences of these species of medical and veterinary importance were compared to those of other heteropterans to infer the evolutionary relationships of species in the family Cimicidae.
2

An Evaluation of Bed Bug (Cimex lectularius L.) Host Location and Aggregation Behavior

Reis, Matthew Douglas 11 January 2011 (has links)
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
3

Evaluation of Alternative Control Methods for Eliminating Insecticide-Resistant Bed Bugs (Cimex lectularius L.)

Todd, Dakotah Brooks 07 February 2023 (has links)
The common bed bug, Cimex lectularius L, has been a persistent pest of humans. Conventional pyrethroid-formulation insecticides are known to be ineffective for controlling modern bed bug populations. This study evaluates alternative treatment methods such as whole-home heat, a biological control agent (Beauveria bassiana), and the fumigant sulfuryl fluoride for control of insecticide-resistant bed bugs. Three heat systems with different energy sources (propane, electric, and glycol) were evaluated to determine attributes contributing to heat treatment efficacy. The glycol system produced the most mortality of the three systems, killing all nymphs, eggs, and most adults. Heat treatment duration and achieving lethal temperatures in complex environments were found to be the most important factors for treatment efficacy. These factors were directly correlated with technician diligence, specifically regarding monitoring surface temperatures and repositioning equipment. A formulation of B. bassiana was evaluated in the laboratory to determine its ability to infect bed bugs under varying conditions of temperature (15°C, 21°C, and 32°C) and humidity (30%, 50%, and 70%). It was found that humidity conditions (30%-50%) at ≈21°C produced the greatest bed bug mortality and the shortest bed bug median survival time. The fumigant sulfuryl fluoride was evaluated for its ability to eliminate bed bugs from motor vehicles and cargo trailers filled to 85% capacity. This study was the first to document that sulfuryl fluoride fumigation at the 1.9X dosage factor can kill all pyrethroid-resistant bed bug life stages (including eggs) in motor vehicles as well as in chambers filled with personal items. / Master of Science in Life Sciences / Since the world-wide bed bug (Cimex lectularius L.) resurgence began in the late 1990s, populations of the common bed bug have been evaluated, but most have been found to be highly resistant to pyrethroid insecticides. This resistance has been particularly troublesome due to the fact that the 1996 US Food Quality Protection Act has eliminated the use of many existing chemistries from indoor use and has inadvertently limited the development of new active ingredients for indoor use due to the cost of the required animal testing to document the No Observable Effects Level (NOEL). Due to the lack of novel chemistry for addressing modern bed bug infestations, pest management professionals have had to identify new methods for applying existing products (chemical and non-chemical) for bed bug control. This study evaluated gaseous, mechanical, and biological control methods for bed bug elimination to determine which factors contribute the most to their efficacy, as well as how these methods might be applied in novel ways for control of bed bugs in homes, personal belongings, and even vehicles. At the turn of the 20th century heat treatments were used for controlling bed bug infestations in homes and other structures. Today, mechanical heating systems are again being used to control bed bug infestations in homes and apartments. This study investigated the utility of three commercial heating systems for their ability to control existing infestations in apartment units. The three heat systems utilized different energy sources, different types of delivery equipment, and required different set up and take down procedures in apartments of different cubic footage and clutter levels. Overall, the Assault glycol heating system was found to be the most effective in its ability to get (almost) all of our hidden (in hard to heat locations) temperature sensors up to bed bug lethal temperature. Interestingly, our statistical analysis determined that getting the hard to heat locations up to lethal temperature was directly correlated with heat technician activity. The more times that the technician entered the home to monitor the treatment and adjust the equipment positions, the greater the chance of getting the hidden sensors up to bed bug lethal temperature (and killing the bed bugs). However, it was also found that none of the heat systems tested killed all of the sentinel bed bugs in every replicate. Therefore, we learned heat treatments cannot be expected to eliminate each and every bed bug in a home, and that supplemental control products such as desiccants dusts should be applied after every heat treatment. When attempting to determine which heat system was the most effective for killing bed bugs, it was determined that regardless of which heat systems was being used, the attention and activity (monitoring temperatures and adjusting equipment) of the heat treatment technician was the most important factor contributing to bed bug mortality as well as the achievement of bed bug lethal temperatures in cracks and crevices for all three systems. Our second study examined the environmental factors that influenced fungal growth after bed bug exposure to the insecticidal product Aprehend® (active ingredient Beauveria bassiana). Over the last several decades, this fungus has been widely used to control multiple insect pests. Recently, it has been labelled for bed bug control in indoor environments. This second study was intended to determine the atmospheric conditions (temperature and humidity) under which Aprehend sporulation was most effective for killing bed bugs. It was found that humidity conditions of 30-50% combined with temperatures of ~21°C produced the highest frequency of fungal infection and the shortest median bed bug survival time. This result was surprising because it was originally hypothesized that the 70% humidity condition would be equally effective for promoting fungal growth. However, at all of the temperatures tested, bed bug fungal infection rates at 70% humidity were not as high as those observed when the humidity was within the 30-50% range. Therefore, this study was able to document that the temperatures and humidity combinations that would typically be found within human homes (21oC at 30-50% humidity) were the most effective for producing fungal infections when bed bugs were exposed to the Aprehend product. The final study addressing novel methods for controlling insecticide resistant bed bugs investigated the efficacy of using Vikane gas fumigant (sulfuryl fluoride) at the 1.9× dosage rate for eliminating bed bugs in two challenging infestation situations: personal vehicles, and confined spaces densely packed with personal belongings. The vehicles used in this study were large minivans with seating that folded into the floor. The confined spaces were cargo trailers filled to 85% capacity with books, furniture, and other household items. Each van and trailer was equipped with ~90 sentinel bed bugs consisting of three groups of 9-11 bed bug eggs, 10 nymphs, and 10 adults. The Vikane Fumiguide calculator was used to determine the target dosage (g-h/m3) to apply in each replicate (e.g., one van or trailer). Sulfuryl fluoride concentrations were measured throughout the fumigation process using a Spectros SF-ReportIR. Concentration readings were input into the Fumiguide to determine when the accumulated dosage (g-h/m3) was achieved, and when aeration should be initiated. After aeration was complete, the sentinel bed bugs were removed from the replicates and bed bug nymph and adult mortality was recorded. Bed bug eggs were monitored for 23 d to determine latent mortality. Fumigated bed bug mortality for each replication was 100% regardless of life stage. Latent mortality was observed in a single bed bug egg, where the nymph never fully hatched. This study determined that fumigation with sulfuryl fluoride at the 1.9× dosage factor is an effective method for eliminating insecticide resistant bed bugs from vehicles and personal belongings in densely packed situations. Overall, it was found that the Beauveria bassiana product was most effective when applied under atmospheric conditions that are typically found in indoor home environments. This discovery was very reassuring, because the Aprehend product is one of very few that actually have residual activity with regard to bed bug control. This study also found that whole home heat treatments require rigorous pest technician attention and monitoring to achieve the best results. It was also determined that heat treatments cannot be assumed to be 100% effective on their own, and that they should be supplemented with additional (residual) treatment applications. Not surprisingly, fumigation with sulfuryl fluoride was determined to be 100% effective for eliminating bed bugs in personal belongings that had been packed into treatment chambers. The fumigation process also proved to be 100% effective for eliminating bed bug infestations in transport vehicles which cannot not be adequately treated and are at risk for having electronic components damaged if treated with heat.
4

Morphological and Physiological Characteristics that Contribute to Insecticide Resistance in Bed Bug (Cimex lectularius L.) Eggs

Delong, Brittany E. 08 July 2014 (has links)
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
5

« Good night, sleep tight, don’t let the bed bugs bite» : exploring the mental health fallout of urban bed bug infestation in Montréal, Québec

Susser, Stephanie Rebecca 08 1900 (has links)
Problématique : La littérature scientifique ne contient actuellement aucune étude épidémiologique portant sur la relation entre l’exposition à une infestation de punaises de lit (Cimex lectularis) et la santé mentale. L’objectif de cette étude est d’explorer la relation entre le statut d’exposition aux punaises de lit et des mesures de dépression, anxiété et perturbation du sommeil. Méthodes : Cette recherche est une étude transversale basée sur une analyse secondaire des données provenant de N=91 adultes locataires de logements insalubres qui ont répondu à un questionnaire de santé au moment d’interventions médico-environnementales menées par la direction de santé publique de Montréal entre janvier et juin 2010. Le questionnaire de santé inclut le « Questionnaire de santé du patient (QSP-9) », qui est un outil mesurant les symptômes associés à la dépression, l’outil de dépistage d’anxiété généralisée (GAD-7) et les items 1-18 de l’indice de la qualité du sommeil de Pittsburgh (PSQI). L’association entre une exposition autorapportée à une infestation de punaises de lit et le niveau de perturbation du sommeil selon la sous-échelle correspondante du PSQI, les symptômes dépressifs selon le QSP-9 et les symptômes anxieux selon le GAD-7, a été évaluée en utilisant une analyse de régression linéaire multivariée. Des données descriptives relatives aux troubles de sommeil autodéclarés et à des comportements reliés à un isolement social, dus à une exposition aux punaises de lit, sont aussi présentées. Résultats : L’échantillon comprenait 38 hommes et 53 femmes. Parmi les 91 participants, 49 adultes ont signalé une exposition aux punaises de lit et de ce nombre, 53,06% (26/49) ont déclaré des troubles de sommeil et 46,94% (23/49) des comportements d’isolement social, en raison de l’exposition. Les adultes exposés à des punaises de lit ont obtenu des résultats significativement plus élevés sur le QSP-9 (p=0,025), le GAD-7 (p=0,026) et sur la sous-échelle mesurant la perturbation du sommeil (p=0,003) comparativement à ceux qui n’étaient pas exposés. Conclusions : Cette première étude exploratoire met en évidence une association significative entre l’état d’exposition aux punaises de lit et des troubles de sommeil, ainsi que des symptômes anxieux et dépressifs, indiquant que ceux qui sont exposés aux punaises de lit représentent un groupe possiblement à risque de développer des problèmes de santé mentale. Ces résultats viennent en appui aux initiatives des décideurs pour organiser des efforts coordonnés d’éradication au niveau des villes et des provinces. / Background : The peer-reviewed literature currently contains no epidemiologic study examining the relationship between exposure to bed bug (Cimex lectularius) infestation and mental health. The objective of this research study is to explore the relationship between bed bug exposure status and measures of depression, anxiety and sleep disturbance. Methods : This is a cross-sectional study based on a secondary analysis of data from N=91 adult tenants of unfit dwellings who responded to a health questionnaire at the time of medico-environmental interventions led by the Montreal Public Health department between January and June 2010. The health questionnaire included the Brief Patient Health Questionnaire Mood Scale (PHQ-9), the Generalized Anxiety Disorder Screener (GAD-7) and items 1-18 of the Pittsburgh Sleep Quality Index (PSQI). The relationship between self reported bed bug exposure and level of sleep disturbance as per the PSQI’s 5th subscale, depressive and anxious symptoms according to the PHQ-9 and the GAD-7 respectively, was evaluated using multivariate linear regression analysis. Descriptive data pertaining to self-reported sleep difficulties and social isolation behaviours due to bed bugs in the exposed subset are also presented. Results : The study sample included 38 men and 53 women. Out of the 91 participants, 49 adults reported bed bug exposure and of these, 53.06% (26/49) reported sleep difficulties and 46.94% (23/49) social isolation behaviours, due to exposure. Adults exposed to bed bugs scored significantly higher on the PHQ-9 (p=0.025), the GAD-7(p=0.026) and on the sleep disturbance subscale, PSQI(5) (p=0.003) compared to those unexposed. Conclusions : This first exploratory study highlights a significant association between bed bug exposure status and sleep disturbance as well as anxious and depressive symptoms, delineating individuals exposed as a possible group at risk for mental health problems. These findings support policy-makers’ initiatives to organize coordinated eradication efforts at the city and state levels.
6

« Good night, sleep tight, don’t let the bed bugs bite» : exploring the mental health fallout of urban bed bug infestation in Montréal, Québec

Susser, Stephanie Rebecca 08 1900 (has links)
Problématique : La littérature scientifique ne contient actuellement aucune étude épidémiologique portant sur la relation entre l’exposition à une infestation de punaises de lit (Cimex lectularis) et la santé mentale. L’objectif de cette étude est d’explorer la relation entre le statut d’exposition aux punaises de lit et des mesures de dépression, anxiété et perturbation du sommeil. Méthodes : Cette recherche est une étude transversale basée sur une analyse secondaire des données provenant de N=91 adultes locataires de logements insalubres qui ont répondu à un questionnaire de santé au moment d’interventions médico-environnementales menées par la direction de santé publique de Montréal entre janvier et juin 2010. Le questionnaire de santé inclut le « Questionnaire de santé du patient (QSP-9) », qui est un outil mesurant les symptômes associés à la dépression, l’outil de dépistage d’anxiété généralisée (GAD-7) et les items 1-18 de l’indice de la qualité du sommeil de Pittsburgh (PSQI). L’association entre une exposition autorapportée à une infestation de punaises de lit et le niveau de perturbation du sommeil selon la sous-échelle correspondante du PSQI, les symptômes dépressifs selon le QSP-9 et les symptômes anxieux selon le GAD-7, a été évaluée en utilisant une analyse de régression linéaire multivariée. Des données descriptives relatives aux troubles de sommeil autodéclarés et à des comportements reliés à un isolement social, dus à une exposition aux punaises de lit, sont aussi présentées. Résultats : L’échantillon comprenait 38 hommes et 53 femmes. Parmi les 91 participants, 49 adultes ont signalé une exposition aux punaises de lit et de ce nombre, 53,06% (26/49) ont déclaré des troubles de sommeil et 46,94% (23/49) des comportements d’isolement social, en raison de l’exposition. Les adultes exposés à des punaises de lit ont obtenu des résultats significativement plus élevés sur le QSP-9 (p=0,025), le GAD-7 (p=0,026) et sur la sous-échelle mesurant la perturbation du sommeil (p=0,003) comparativement à ceux qui n’étaient pas exposés. Conclusions : Cette première étude exploratoire met en évidence une association significative entre l’état d’exposition aux punaises de lit et des troubles de sommeil, ainsi que des symptômes anxieux et dépressifs, indiquant que ceux qui sont exposés aux punaises de lit représentent un groupe possiblement à risque de développer des problèmes de santé mentale. Ces résultats viennent en appui aux initiatives des décideurs pour organiser des efforts coordonnés d’éradication au niveau des villes et des provinces. / Background : The peer-reviewed literature currently contains no epidemiologic study examining the relationship between exposure to bed bug (Cimex lectularius) infestation and mental health. The objective of this research study is to explore the relationship between bed bug exposure status and measures of depression, anxiety and sleep disturbance. Methods : This is a cross-sectional study based on a secondary analysis of data from N=91 adult tenants of unfit dwellings who responded to a health questionnaire at the time of medico-environmental interventions led by the Montreal Public Health department between January and June 2010. The health questionnaire included the Brief Patient Health Questionnaire Mood Scale (PHQ-9), the Generalized Anxiety Disorder Screener (GAD-7) and items 1-18 of the Pittsburgh Sleep Quality Index (PSQI). The relationship between self reported bed bug exposure and level of sleep disturbance as per the PSQI’s 5th subscale, depressive and anxious symptoms according to the PHQ-9 and the GAD-7 respectively, was evaluated using multivariate linear regression analysis. Descriptive data pertaining to self-reported sleep difficulties and social isolation behaviours due to bed bugs in the exposed subset are also presented. Results : The study sample included 38 men and 53 women. Out of the 91 participants, 49 adults reported bed bug exposure and of these, 53.06% (26/49) reported sleep difficulties and 46.94% (23/49) social isolation behaviours, due to exposure. Adults exposed to bed bugs scored significantly higher on the PHQ-9 (p=0.025), the GAD-7(p=0.026) and on the sleep disturbance subscale, PSQI(5) (p=0.003) compared to those unexposed. Conclusions : This first exploratory study highlights a significant association between bed bug exposure status and sleep disturbance as well as anxious and depressive symptoms, delineating individuals exposed as a possible group at risk for mental health problems. These findings support policy-makers’ initiatives to organize coordinated eradication efforts at the city and state levels.

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