• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • 1
  • Tagged with
  • 14
  • 14
  • 7
  • 5
  • 5
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 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

Modulation of effector gene expression in the blood-feeding arthropods Cimex lectularius Linnaeus, (Hemiptera: Cimicidae) and Aedes albopictus Skuse, (Diptera: Culicidae)

van Warmerdam, Travis C 10 December 2021 (has links) (PDF)
Hematophagy, or blood-feeding behavior, has independently evolved multiple times in the class Insecta and results in the transmission of vector-borne parasites, bacteria and viruses causing 17% of all infectious diseases and over 700,000 human deaths annually. One of the major challenges in studying the discrete mechanisms involved in host-response to hematophagy or the host seeking behavior of hematophagous insects, is the vast amount of signaling processes and genes that are inextricably tied to these interactions. These experiments used the clustered regularly interspersed short palindromic repeat (CRISPR)/CRISPR-associated (Cas) and dsRNA knock-down technologies to examine mechanisms of immunological reactivity and host-seeking behavior. Using Illumina next-generation sequencing, 19,269 unique genes were found to be expressed in the salivary glands of C. lectularius. Of those genes, a total of 10,587 were differentially expressed. There were 6 genes definitively characterized as nitrophorin or nitrophorin-like, which were targeted for RNAi experiments. Silencing two nitrophorin genes, LOC106662976 and LOC106662977, which were the most highly expressed, did not result in any significant changes in feeding behavior or dermal reaction in the host. While RNAi-based knock-down experiments can gauge a proteins function, CRISPR/Cas-based knock-out experiments more definitively assess functionality. The second part of the study is thus focused on performing the first homology directed repair knock-in in Ae. albopictus using a plasmid, Cas9 protein and sgRNA targeting the key olfactory receptor gene, AealbOR4. An injection plasmid was constructed targeting AealbOR4 using standard molecular methods. Preliminary injections of the plasmid yielded no viable embryos. To determine if it is the plasmid or injection components that are lethal to developing Ae. albopictus embryos, further studies are required. Despite this, the development of this technique is a first step to be able to effectively interrogate gene function of an olfactory receptor and its role in host-seeking behavior. Taken together, these studies indicate that both RNAi and CRISPR/Cas-based gene editing technologies can effectively be utilized to answer some of the intricate questions related to insect-host interactions in the future.
2

Descrição das Infestações e estudo morfométrico de percevejos de cama (Hemiptera: Cimicidae) do Estado de São Paulo / Description of infestations and morphometric study Bed Bug (Hemiptera: Cimicidae) in the State of Sao Paulo.

Lage, Marcio Rodrigues 29 April 2014 (has links)
Os cimicídeos, conhecidos popularmente como percevejos-de-cama, são insetos hematófagos durante os estágios de ninfas e adulto. Algumas espécies apresentam marcante antropofilia e apesar de não transmitirem patógenos, podem causar algumas complicações a saúde humana, como alergias graves e anemia. O número de infestações nos últimos anos em muitos países tem aumentado significativamente e a relação com lugares de baixo IDH não é mais observada, inclusive na cidade de São Paulo. A precariedade nos estudos dificulta o conhecimento sobre as infestações. No presente estudo, teve-se o objetivo descrever infestações no estado de São Paulo e seus aspectos, e estudar a morfologia dos percevejos de cama encontrados, através de análise morfométrica. Foram coletadas e descritas cinco infestações, quatro na cidade de São Paulo e uma na cidade de Mirandópolis. Os resultados sugerem haver falta de conhecimento da população sobre esta praga urbana e comfirmam Cimex lectularius como principal espécie presente no estado de São Paulo, assim como sugere uma proximidade populacional das infestações dentro da cidade de São Paulo em relação a infestações de outras localidades. Porém os estudos devem ser estimulados no intuito de enriquecer o conhecimento sobre estes insetos, haja vista o grande fluxo de pessoas e a possibilidade de agravamento das infestações, uma vez que grandes eventos internacionais ocorrerão em capitais brasileiras. / The Cimicidae, commonly known as bedbugs are bloodsucking insects throughout all their life cycle. Some species show striking anthropophily and despite they dont transmit diseases they can cause some complications for human health, such as severe allergies and anemia. The number of infestations over the last few years in many countries has increased significantly compared to places with low HDI that is no longer observed, including São Paulo city. The lack of studies hinders knowledge about infestations. The present study aims to describe infestations in the state of São Paulo and its aspects, and to study the morphology of bedbugs found, through morphometric analysis. Five infestations in the city of São Paulo and one in the city of Mirandópolis were collected and described. The results suggest lack of knowledge of the population about this urban blight and confirm Cimex lectularius as the main species present in the state of São Paulo. Also suggests proximity of infestations within the city of São Paulo in relation to infestations of other localities. However, the studies should be encouraged in order to enrich the knowledge about these insects, considering the large flow of people and the possibility of aggravating the infestation, since large international events will occur in the largest Brazilian cities.
3

Identificação de métodos e produtos utilizados, bem como o perfil das empresas especializadas no controle de vetores e pragas urbanas, com ênfase em percevejos de cama (hemiptera:cimicidae) / Identification of Methods and Products Used, as well as the Profile of the Pest Control Companies, with Emphasis on Bed Bugs (Hemiptera: Cimicidae)

Bocalini, Sérgio dos Santos 13 October 2015 (has links)
Os percevejos de cama são insetos pertencentes a ordem Hemiptera e a família Cimicidae, com metamorfose hemimetábola, possuem comportamento antropofílico e exercem a hematofagia nas fases de ninfa e adulto, o que desperta interesse em saúde pública. O reaparecimento desta praga tem levado diversas pessoas a buscarem nas empresas especializadas uma forma de exercer o controle. O presente estudo teve como objetivo identificar, no período de maio de 2013 a maio de 2015, as formas de controle e produtos utilizados, bem como o perfil das empresas especializadas no controle de vetores e pragas urbanas instaladas no Brasil. O estudo foi realizado por meio de uma enquete enviada a 2136 empresas brasileiras e questionário eletrônico enviado para as empresas. Foram encaminhadas 2136 cartas convites para participação. Como resultado foi obtido 158 enquetes respondidas e estas empresas foram então convidadas a responder um questionário com perguntas direcionadas ao controle de percevejos de cama. Apenas 13 questionários foram recebidos de empresas localizadas na região Sul, Sudeste, Centro-Oeste e Nordeste. A maioria das empresas que realiza o controle de percevejos de cama está na área de controle de pragas urbanas a mais de 21 anos e utiliza preferencialmente pesticidas para o controle dos insetos. Quase 50 por cento dos responsáveis técnicos dessas empresas não fizeram qualquer treinamento sobre controle de cimicídeos nos últimos dois anos e informações sobre o inseto e seu manejo não são passadas ao cliente. O baixo retorno dos questionários preenchidos nesta pesquisa pode ser devido ao pouco conhecimento que as empresas têm sobre o controle de percevejos de cama, o que pode tê-las inibido em fornecer informações. Desta maneira, informações técnicas e treinamentos sobre o controle de percevejos de cama se faz necessário, uma vez que o controle ainda está pautado na utilização de produtos químicos e que esta estratégia pode incorrer em riscos de intoxicação quando feita de maneira inadequada principalmente pela falta de capacitação dos responsáveis técnicos. / Bed bugs belong to the order Hemiptera and family Cimicidae with hemimetabolous metamorphosis; they show anthropophilic behavior and are hematophagous at nymph and adult stages, which causes interest in public health. The reappearance of this pest has led many people to seek for pest control companies to control it. This study aimed to identify, from May 2013 to May 2015, which are the control strategies and used products as well as the profile of the pest control companies in Brazil. The study was made through an electronic survey sent to 2136 Brazilian companies, One hundred and fifty eight companies answered the survey and were invited to fill in a questionnaire on bed bug control. Only 13 questionnaires were received from companies located in the South, Southeast, Midwest and Northeast regions of Brazil. Most companies that make bed bug control are in the area for more than 21 years and they use mainly pesticides to control the insects. Almost 50 per cent of the technical managers of these companies did not attend to any training on bed bug control in the last two years, and information on their management is not given to their clients. The few questionnaires received are probably due to the little knowledge that pest control companies have on bed bugs, which may have inhibited them to provide information. In this way, technical information and training on the bed bug control is necessary, since the control is still founded on the use of chemicals and that this strategy may incur intoxication risk when done improperly mainly by lack of training of technical experts.
4

Identificação de métodos e produtos utilizados, bem como o perfil das empresas especializadas no controle de vetores e pragas urbanas, com ênfase em percevejos de cama (hemiptera:cimicidae) / Identification of Methods and Products Used, as well as the Profile of the Pest Control Companies, with Emphasis on Bed Bugs (Hemiptera: Cimicidae)

Sérgio dos Santos Bocalini 13 October 2015 (has links)
Os percevejos de cama são insetos pertencentes a ordem Hemiptera e a família Cimicidae, com metamorfose hemimetábola, possuem comportamento antropofílico e exercem a hematofagia nas fases de ninfa e adulto, o que desperta interesse em saúde pública. O reaparecimento desta praga tem levado diversas pessoas a buscarem nas empresas especializadas uma forma de exercer o controle. O presente estudo teve como objetivo identificar, no período de maio de 2013 a maio de 2015, as formas de controle e produtos utilizados, bem como o perfil das empresas especializadas no controle de vetores e pragas urbanas instaladas no Brasil. O estudo foi realizado por meio de uma enquete enviada a 2136 empresas brasileiras e questionário eletrônico enviado para as empresas. Foram encaminhadas 2136 cartas convites para participação. Como resultado foi obtido 158 enquetes respondidas e estas empresas foram então convidadas a responder um questionário com perguntas direcionadas ao controle de percevejos de cama. Apenas 13 questionários foram recebidos de empresas localizadas na região Sul, Sudeste, Centro-Oeste e Nordeste. A maioria das empresas que realiza o controle de percevejos de cama está na área de controle de pragas urbanas a mais de 21 anos e utiliza preferencialmente pesticidas para o controle dos insetos. Quase 50 por cento dos responsáveis técnicos dessas empresas não fizeram qualquer treinamento sobre controle de cimicídeos nos últimos dois anos e informações sobre o inseto e seu manejo não são passadas ao cliente. O baixo retorno dos questionários preenchidos nesta pesquisa pode ser devido ao pouco conhecimento que as empresas têm sobre o controle de percevejos de cama, o que pode tê-las inibido em fornecer informações. Desta maneira, informações técnicas e treinamentos sobre o controle de percevejos de cama se faz necessário, uma vez que o controle ainda está pautado na utilização de produtos químicos e que esta estratégia pode incorrer em riscos de intoxicação quando feita de maneira inadequada principalmente pela falta de capacitação dos responsáveis técnicos. / Bed bugs belong to the order Hemiptera and family Cimicidae with hemimetabolous metamorphosis; they show anthropophilic behavior and are hematophagous at nymph and adult stages, which causes interest in public health. The reappearance of this pest has led many people to seek for pest control companies to control it. This study aimed to identify, from May 2013 to May 2015, which are the control strategies and used products as well as the profile of the pest control companies in Brazil. The study was made through an electronic survey sent to 2136 Brazilian companies, One hundred and fifty eight companies answered the survey and were invited to fill in a questionnaire on bed bug control. Only 13 questionnaires were received from companies located in the South, Southeast, Midwest and Northeast regions of Brazil. Most companies that make bed bug control are in the area for more than 21 years and they use mainly pesticides to control the insects. Almost 50 per cent of the technical managers of these companies did not attend to any training on bed bug control in the last two years, and information on their management is not given to their clients. The few questionnaires received are probably due to the little knowledge that pest control companies have on bed bugs, which may have inhibited them to provide information. In this way, technical information and training on the bed bug control is necessary, since the control is still founded on the use of chemicals and that this strategy may incur intoxication risk when done improperly mainly by lack of training of technical experts.
5

Descrição das Infestações e estudo morfométrico de percevejos de cama (Hemiptera: Cimicidae) do Estado de São Paulo / Description of infestations and morphometric study Bed Bug (Hemiptera: Cimicidae) in the State of Sao Paulo.

Marcio Rodrigues Lage 29 April 2014 (has links)
Os cimicídeos, conhecidos popularmente como percevejos-de-cama, são insetos hematófagos durante os estágios de ninfas e adulto. Algumas espécies apresentam marcante antropofilia e apesar de não transmitirem patógenos, podem causar algumas complicações a saúde humana, como alergias graves e anemia. O número de infestações nos últimos anos em muitos países tem aumentado significativamente e a relação com lugares de baixo IDH não é mais observada, inclusive na cidade de São Paulo. A precariedade nos estudos dificulta o conhecimento sobre as infestações. No presente estudo, teve-se o objetivo descrever infestações no estado de São Paulo e seus aspectos, e estudar a morfologia dos percevejos de cama encontrados, através de análise morfométrica. Foram coletadas e descritas cinco infestações, quatro na cidade de São Paulo e uma na cidade de Mirandópolis. Os resultados sugerem haver falta de conhecimento da população sobre esta praga urbana e comfirmam Cimex lectularius como principal espécie presente no estado de São Paulo, assim como sugere uma proximidade populacional das infestações dentro da cidade de São Paulo em relação a infestações de outras localidades. Porém os estudos devem ser estimulados no intuito de enriquecer o conhecimento sobre estes insetos, haja vista o grande fluxo de pessoas e a possibilidade de agravamento das infestações, uma vez que grandes eventos internacionais ocorrerão em capitais brasileiras. / The Cimicidae, commonly known as bedbugs are bloodsucking insects throughout all their life cycle. Some species show striking anthropophily and despite they dont transmit diseases they can cause some complications for human health, such as severe allergies and anemia. The number of infestations over the last few years in many countries has increased significantly compared to places with low HDI that is no longer observed, including São Paulo city. The lack of studies hinders knowledge about infestations. The present study aims to describe infestations in the state of São Paulo and its aspects, and to study the morphology of bedbugs found, through morphometric analysis. Five infestations in the city of São Paulo and one in the city of Mirandópolis were collected and described. The results suggest lack of knowledge of the population about this urban blight and confirm Cimex lectularius as the main species present in the state of São Paulo. Also suggests proximity of infestations within the city of São Paulo in relation to infestations of other localities. However, the studies should be encouraged in order to enrich the knowledge about these insects, considering the large flow of people and the possibility of aggravating the infestation, since large international events will occur in the largest Brazilian cities.
6

Insecticide Resistance in the Bed Bug

Gordon, Jennifer R 01 January 2014 (has links)
Populations of Cimex lectularius, the bed bug, have resurged around the world posing significant challenges for pest management professionals and causing physical, economic, and emotional strife. Pyrethroid resistance has been found in the vast majority of populations making pest management more difficult. The objectives of my dissertation research were to document the evolution of resistance to pyrethroid and neonicotinoid combination products (called combination products here) and to a neonicotinoid in the laboratory, to record potential fitness costs to resistance to the combination products, and to compare the efficacy of nine insecticides on six populations. In the laboratory, populations of bed bugs evolve resistance rapidly to a combination product and that resistance translates into cross resistance to another combination product. In a follow up experiment, resistance to a neonicotinoid occurred after three generations of selection. Cross resistance between neonicotinoid and pyrethroid resistance was also found, likely due to a common detoxification mechanism (cytochrome P450 mediated metabolism). Resistance was associated with life history costs in three populations that had been selected with a combination product. Therefore, in the absence of selection pressure, populations of bed bugs should revert towards increasing susceptibility. Two pyrethroid products and three combination products were effective at killing three populations of bed bugs but were relatively ineffective against three other populations. However, the combination product, Transport GHP®, the single action pyrrole product, Phantom SC®, and the single action desiccant, CimeXa®, killed 95 to 100% of all populations investigated over a 14-day exposure. Taken together, results reported in this dissertation suggest that insecticide resistance management may be a useful tool for extending the efficacy of insecticides for control of C. lectularius.
7

Bed Bug (<i>Cimex lectularius</i>) Defecation Behavior Following a Blood Meal

Darrington, Courtney L. 20 May 2015 (has links)
No description available.
8

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
9

Life History of the Common Bed Bug Cimex lectularius L. in the U.S.

Polanco, Andrea M. 15 April 2011 (has links)
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
10

Atualização dos conhecimentos sobre o percevejo de cama Cimex lectularius (Hemiptera: Cimicidae): proposta para um guia de vigilância e controle / Update of the knowledge about bed bug Cimex lectularius (Hemiptera: Cimicidae): proposal for a guide of surveillance and control

Figueiredo, Júlia Vono Alvarez 13 November 2018 (has links)
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.

Page generated in 0.0669 seconds