Brazil has 58 species of chigger mites parasitizing different animal groups. Of these, only 6 species were reported for birds, being 1 of Apolonia, 2 of Eutrombicula, 1 of Neoschoengastia and 2 of Parasecia. The larvae of chiggers cause deep lesions and cutaneous reactions in the host, and are often cited as vectors of pathogens. In the United States, public health departments have come across the need for cataloging and knowledge of the biology of these mites as potential vectors of Rickettsia spp. In Brazil, the first cases of Brazilian Macular Fever (BMF) diagnosed in São Paulo were associated with these mites because they were found in outbreaks of the disease. However, its role in the epidemiology of rickettsial disease has not been confirmed. Another concern is dermatitis caused by the bite of these mites, popularly known as trombiculiasis. As it is well known, thrombiculid mites are not specific and several cases of bites in humans have been reported. Thus, the purpose of the present study is to know the current situation of chigger mites parasitizing birds, to clarify aspects of its taxonomic complexity, as well as to provide information about its participation in the epidemiology of Rickettsia in some localities in the southeastern region of the country. From the material examined in the present study were identified 8 species: Blankaartia shatrovi n. sp., Blankaartia sinnamaryi, Microtrombicula n. sp., Eutrombicula tinami, Eutrombicula goeldii, Parasecia n. sp.1, Parasecia n. sp.2, Parasecia n. sp.3. The mites were kept in absolute alcohol, were submitted to DNA extraction and investigation of the presence of Rickettsia. One of the samples showed 100% for Rickettsia felis. Therefore, for Brazil now, we have 13 species described for the entire national territory, with the exception of the Midwest region, and, in addition, the first record of the presence of Rickettsia in chigger mites on South America. / O Brasil possui 58 espécies de ácaros trombiculídeos parasitando diferentes grupos animais. E destas, somente 6 espécies foram reportadas para aves, sendo 1 de Apolonia, 2 de Eutrombicula, 1 de Neoschoengastia e 2 de Parasecia. As larvas de trombiculídeos provocam lesões profundas e reações cutâneas no hospedeiro, sendo por muitas vezes citados como vetores de agentes patogênicos. Nos Estados Unidos, os departamentos de saúde pública se depararam com a necessidade de catalogação e conhecimento da biologia desses ácaros por serem considerados potenciais vetores de Rickettsia spp. No Brasil, os primeiros casos de Febre Maculosa Brasileira (FMB) diagnosticados em São Paulo, foram associados a esses ácaros porque terem sido encontrados em focos da doença. No entanto, o seu papel na epidemiologia da riquetsiose não foi confirmado. Outra preocupação é a dermatite causada pela mordida desses ácaros, popularmente conhecida como trombiculíase. Como é bem conhecido, trombiculídeos não são específicos e vários casos de mordidas em humanos já foram relatados. Dessa forma, a proposta do presente estudo é conhecer a situação atual dos trombiculídeos de aves, esclarecer os aspectos de sua complexidade taxonômica, bem como fornecer informações sobre sua participação na epidemiologia de riquétsias em algumas localidades da região sudeste do país. Do material examinado no presente estudo foram identificadas 8 espécies: Blankaartia shatrovi sp. n., Blankaartia sinnamaryi, Microtrombicula sp. n., Eutrombicula tinami, Eutrombicula goeldii, Parasecia sp. n.1, Parasecia sp. n.2, Parasecia sp. n.3. Os ácaros mantidos em álcool absoluto foram submetidos à extração de DNA e investigação da presença de Rickettsia. Uma das amostras aprentou 100% para Rickettsia felis. Portanto, para o Brazil agora, temos 13 espécies descritas para todo o território nacional, com excessão da região Centro-Oeste, e, além disso, o primeiro registro da presença de Rickettsia em ácaros trombiculídeos da América do Sul.

Brazil has 58 species of chigger mites parasitizing different animal groups. Of these, only 6 species were reported for birds, being 1 of Apolonia, 2 of Eutrombicula, 1 of Neoschoengastia and 2 of Parasecia. The larvae of chiggers cause deep lesions and cutaneous reactions in the host, and are often cited as vectors of pathogens. In the United States, public health departments have come across the need for cataloging and knowledge of the biology of these mites as potential vectors of Rickettsia spp. In Brazil, the first cases of Brazilian Macular Fever (BMF) diagnosed in São Paulo were associated with these mites because they were found in outbreaks of the disease. However, its role in the epidemiology of rickettsial disease has not been confirmed. Another concern is dermatitis caused by the bite of these mites, popularly known as trombiculiasis. As it is well known, thrombiculid mites are not specific and several cases of bites in humans have been reported. Thus, the purpose of the present study is to know the current situation of chigger mites parasitizing birds, to clarify aspects of its taxonomic complexity, as well as to provide information about its participation in the epidemiology of Rickettsia in some localities in the southeastern region of the country. From the material examined in the present study were identified 8 species: Blankaartia shatrovi n. sp., Blankaartia sinnamaryi, Microtrombicula n. sp., Eutrombicula tinami, Eutrombicula goeldii, Parasecia n. sp.1, Parasecia n. sp.2, Parasecia n. sp.3. The mites were kept in absolute alcohol, were submitted to DNA extraction and investigation of the presence of Rickettsia. One of the samples showed 100% for Rickettsia felis. Therefore, for Brazil now, we have 13 species described for the entire national territory, with the exception of the Midwest region, and, in addition, the first record of the presence of Rickettsia in chigger mites on South America. / O Brasil possui 58 espécies de ácaros trombiculídeos parasitando diferentes grupos animais. E destas, somente 6 espécies foram reportadas para aves, sendo 1 de Apolonia, 2 de Eutrombicula, 1 de Neoschoengastia e 2 de Parasecia. As larvas de trombiculídeos provocam lesões profundas e reações cutâneas no hospedeiro, sendo por muitas vezes citados como vetores de agentes patogênicos. Nos Estados Unidos, os departamentos de saúde pública se depararam com a necessidade de catalogação e conhecimento da biologia desses ácaros por serem considerados potenciais vetores de Rickettsia spp. No Brasil, os primeiros casos de Febre Maculosa Brasileira (FMB) diagnosticados em São Paulo, foram associados a esses ácaros porque terem sido encontrados em focos da doença. No entanto, o seu papel na epidemiologia da riquetsiose não foi confirmado. Outra preocupação é a dermatite causada pela mordida desses ácaros, popularmente conhecida como trombiculíase. Como é bem conhecido, trombiculídeos não são específicos e vários casos de mordidas em humanos já foram relatados. Dessa forma, a proposta do presente estudo é conhecer a situação atual dos trombiculídeos de aves, esclarecer os aspectos de sua complexidade taxonômica, bem como fornecer informações sobre sua participação na epidemiologia de riquétsias em algumas localidades da região sudeste do país. Do material examinado no presente estudo foram identificadas 8 espécies: Blankaartia shatrovi sp. n., Blankaartia sinnamaryi, Microtrombicula sp. n., Eutrombicula tinami, Eutrombicula goeldii, Parasecia sp. n.1, Parasecia sp. n.2, Parasecia sp. n.3. Os ácaros mantidos em álcool absoluto foram submetidos à extração de DNA e investigação da presença de Rickettsia. Uma das amostras aprentou 100% para Rickettsia felis. Portanto, para o Brazil agora, temos 13 espécies descritas para todo o território nacional, com excessão da região Centro-Oeste, e, além disso, o primeiro registro da presença de Rickettsia em ácaros trombiculídeos da América do Sul.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-11T21:16:25Z No. of bitstreams: 1 2012 - Matheus Dias Cordeiro.pdf: 852495 bytes, checksum: c420562c23340ca737374426f8c5e0f7 (MD5) / Made available in DSpace on 2017-04-11T21:16:25Z (GMT). No. of bitstreams: 1 2012 - Matheus Dias Cordeiro.pdf: 852495 bytes, checksum: c420562c23340ca737374426f8c5e0f7 (MD5) Previous issue date: 2012-02-29 / CNPq / Brazilian Spotted Fever and Baggio-Yoshinari Syndrome are emerging diseasest characterized as the only known to tick-borne zoonoses in Brazil. This study aimed to avaluate IgG antibodies against Borrelia burgdorferi and Rickettsia rickettsii in stray and domiciled dogs from Serop?dica-RJ and studying the fauna of ixodida these animals. To investigate the prevalence of antibodies against R. rickettsii and B. burgdorferi was performed to collect blood from 293 dogs in four areas of the city of Serop?dica-RJ. Serum samples were processed by Indirect Immunofluorescence (IFA) against crude antigens of R. rickettsii. The same animals were tested for IgG antibodies against B. burgdorferi strain of North American origin, using the Indirect Enzyme-linked immunosorbent assay (ELISA). To confirm the presence of Borrelia spp., 102 positive samples were tested by Western Blotting (WB). Ticks were also collected from the inspection of the animals. The specimens found were manually removed and stored in polypropylene bottles, and later identified. The association between seropositive animals and variables, were performed using the chi-square and analysis of variance (ANOVA) with significance level of 5%. Of the 283 sera tested by IFA, 23.67% (67/283) showed reactivity against species-specific antigens of R. rickettsii. Thus, we found a prevalence of 21.11% (19/90) in "40 km", 21.84% (19/87) in "Km 49", 25% (8 / 32) in "54 km" and 28.38% (21/74) in UFRRJ. The titles ranged from 1:64 to 1:512. On the other hand, of the 293 animals studied, 154 (52.56%) were positive for homologous antibodies anti-B. burgdorferi. It was founded a prevalence of 43.75% (14/32) in the "54 km", 51.72% (45/87) in the "49 km", 46.67% (42/90) in the "40 km" and 63.1% (53/84) in UFRRJ. It was no significant difference (p<0.05) between the prevalence of antibodies against Borrelia sp. in stray dogs and domiciled. Dogs with access to the street had a frequency against R. rickettsii significantly (p<0.05) greater than animals kept in prison. There were no statistical differences (p>0.05) the relationship between the variables: presence of ticks, animal sex, habits, frequenting pastures and age of the animals with seropositivity observed in either species. Regarding ticks, at least 64.5% (189/293) dogs were infested with ticks at the moment of collection. Only two species of ticks were identified, Rhipicephalus sanguineus and Amblyomma cajennense. The presence of antibodies anti-R. rickettsii and anti-B. burgdorferi in dogs from Serop?dica-RJ is indicative of the presence of rickettsias of the Rock Mountain Spotted Fever Group and spirochetes dogs in this area. / A Febre Maculosa Brasileira e a S?ndrome de Baggio-Yoshinari s?o enfermidades emergentes, caracterizadas como as ?nicas zoonoses conhecidamente transmitidas por carrapatos, no Brasil. O presente estudo teve como objetivo detectar anticorpos da classe IgG contra Rickettsia rickettsii e Borrelia burgdorferi e estudar a fauna de Ixod?deos nesses animais. Para investigar a preval?ncia de anticorpos contra R. rickettsii e B. burgdorferi foi efetuada a coleta de sangue de 293 c?es, em quatro ?reas do munic?pio de Serop?dica-RJ. Os soros obtidos foram processados atrav?s da Rea??o de Imunofluoresc?ncia Indireta (RIFI), contra ant?genos brutos de R. rickettsii. Os mesmos animais foram submetidos ? pesquisa de anticorpos hom?logos da classe IgG contra B. burgdorferi cepa americana G39/40, utilizando Ensaio de Imunoadsor??o Enzim?tico (ELISA) Indireto. Para confirma??o da presen?a de Borrelia spp. no munic?pio, 102 amostras positivas foram testadas pelo Western Blotting (WB). A fauna de ixod?deos foi estudada atrav?s da coleta de carrapatos a partir da inspe??o das regi?es das orelhas, dorso e coxins palmares e plantares dos animais. Os esp?cimes encontrados foram removidos manualmente e acondicionados em frascos de polipropileno, e posteriormente, identificados. O estudo da associa??o entre animais soropositivos e as vari?veis avaliadas, foram realizados por meio do teste de Qui-quadrado e An?lise de Vari?ncia (ANOVA), com n?vel de signific?ncia de 5%. Dos 283 soros testados ? RIFI, 23,67% (67/283) apresentaram reatividade contra ant?genos esp?cie-espec?fico de R. rickettsii, sendo encontrada uma frequ?ncia de 21,11% (19/90) no ?Km 40?, 21,84% (19/87) no ?Km 49?, 25% (8/32) no ?Km 54? e 28,38% (21/74) no campus da UFRRJ. A titula??o variou entre 1:64 ? 1:512. Por outro lado, dos 293 animais estudados, 154 (52,56%) foram positivos para anticorpos hom?logos anti-B. burgdorferi, sendo encontrada uma frequ?ncia de 43,75% (14/32) no ?Km 54?, 51,72% (45/87) no ?Km 49?, 46,67% (42/90) no ?Km 40? e 63,1% (53/84) na UFRRJ. Houve diferen?a significativa (p<0,05) entre as preval?ncias de anticorpos contra Borrelia spp. encontradas em caninos errantes e domiciliados. Os c?es com acesso a rua tiveram uma frequ?ncia de anticorpos contra R. rickettsii significativamente (p<0,05) maior que animais mantidos preso. N?o foram observadas diferen?as estat?sticas (p>0,05) entre a rela??o das vari?veis: presen?a de carrapatos, sexo dos animais, h?bitos de frequentar pastos e idade dos animais com a soropositividade observada em nenhuma das duas esp?cies. Quanto aos carrapatos, 64,5% (189/293) dos c?es estavam infestados por carrapatos no momento da coleta. Apenas duas esp?cies de carrapatos foram identificadas, Rhipicephalus sanguineus e Amblyomma cajennense. A presen?a de anticorpos hom?logos anti-R. rickettsii e anti-B. burgdorferi em caninos de Serop?dica-RJ ? um indicativo da presen?a de rickettsia do grupo da Febre Maculosa e espiroquetas em c?es nesta ?rea.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-18T13:01:13Z No. of bitstreams: 1 daniellealnavarro.pdf: 600639 bytes, checksum: c614912f6fd31f4aa5eddd47114bc93d (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-02-26T13:29:34Z (GMT) No. of bitstreams: 1 daniellealnavarro.pdf: 600639 bytes, checksum: c614912f6fd31f4aa5eddd47114bc93d (MD5) / Made available in DSpace on 2016-02-26T13:29:34Z (GMT). No. of bitstreams: 1 daniellealnavarro.pdf: 600639 bytes, checksum: c614912f6fd31f4aa5eddd47114bc93d (MD5) Previous issue date: 2014-02-24 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A Febre Maculosa é uma zoonose causada por bactérias do gênero Rickettsia. A relação natural entre vetores e seus hospedeiros vertebrados, durante o ciclo enzoótico, pode variar no tempo e espaço, evidenciando uma complexidade epidemiológica que deve ser investigada e monitorada como principal indicador para as ações de políticas públicas na prevenção e controle de casos humanos. Nesse aspecto, cães e equinos podem atuar como sentinelas, sinalizando a circulação de riquétsias em uma região, bem como servindo como dispersores de potenciais vetores, permitindo, assim, a amplificação de um foco já estabelecido ou o estabelecimento de novos focos. Com o objetivo de melhor entender a circulação de riquétsia através de pesquisa sorológica no perímetro urbano do município de Juiz de Fora, Minas Gerais, Brasil, considerado área endêmica para febre maculosa, sangue de cães e equinos de diversas regiões foram testados através da Reação de imunofluorescência indireta (RIFI) e Reação em Cadeia da Polimerase (PCR). As amostras resultaram 12,75% (31/243) de cães e 23,68% (9/38) de equinos pela RIFI com títulos ≥ 1:64. Na PCR foram utilizados iniciadores para amplificar fragmentos dos genes gltA e ompA. Nenhum resultado positivo foi encontrado. O maior número de cães positivos ocorreu na região leste da cidade, área com casos humanos descritos entre 2007 e 2008. Entretanto, a maior prevalência e concentração de títulos elevados em cães foi assinalada na região norte, área com casos recentes confirmados (2012), resultado semelhante àquele obtido para equinos, confirmando uma maior atividade dos focos naquela região. Áreas sem caso humano confirmado apresentaram animais com altos títulos, sugerindo um potencial risco para a população. Os resultados confirmam o papel de cães e equinos no ciclo enzoótico de riquétsias na região estudada e seu potencial como indicadores epidemiológicos para a investigação de casos e vigilância de ambiente na febre maculosa. / Spotted Fever is a zoonotic disease caused by bacteria of the genus Rickettsia. The natural relationship between vectors and their vertebrate hosts during the enzootic cycle, may vary in time and space, showing an epidemiological complexity that must be investigated and monitored as a key indicator for the actions of public policy in the prevention and control of human cases. This way, dogs and horses are sentinels, indicating the movement of Rickettsia sp. in a region and serving as dispersers of vectors, allowing the amplification of a focus or establishing new foci. To better understanding of the movement of Rickettsia sp. in the urban area of Juiz de Fora, Minas Gerais, Brazil , endemic area for spotted fever, blood of dogs and horses from different regions were tested by indirect immunofluorescence assay (IFA ) and Polymerase Chain Reaction ( PCR ). Samples resulted 12.75% (31/ 243) of dogs and 23.68 % ( 9/38 ) equine with titers ≥ 1:64. PCR primers were used to amplify fragments of the gltA and ompA genes, no positive results. The highest number of positive dogs occurred in the east region, an area with human cases reported between 2007 and 2008. However, the highest prevalence and concentration of high titers in dogs was reported in the northern region, an area with confirmed recent cases ( 2012 ). Similar results were obtained from equine, confirming a higher activity in the foci of the region. Areas with no human case presented animals with high titers, suggesting a potential risk for the population. The results confirm the role of dogs and horses in the enzootic cycle of Rickettsia in the region studied and its potential as epidemiological indicators for the investigation of cases and monitoring of spotted fever in the environment.

The recent discovery of Amblyomma maculatum sensu lato (s. l.) ticks in southern Arizona has renewed discussions around species designations for members of the Amblyomma maculatum tick group. Amblyomma maculatum s. l. from Arizona appear to be morphologically intermediate between A. maculatum sensu stricto (s. s.) and A. triste s. s. At present there is no conclusive species designation for the ticks from Arizona. My research focused on analyzing the systematics of both A. maculatum s. l. and Rickettsia parkeri, a common bacterial pathogen transmitted by these ticks. In the laboratory, A. maculatum s. l. from Arizona and A. maculatum s. s. from Georgia readily mated on experimental animals to produce F1 hybrid ticks; there was no difference in fertility with these two populations when compared with homologous populations. However, the F1 hybrids produced during these experiments exhibited diminished fitness and did not produce a viable F2 generation. These results suggest that A. maculatum s. l. and A. maculatum s. s. represent separate biological species. Results of the crossbreeding experiment conflict with recent genetic analyses of A. maculatum s. l. and A. maculatum s. s. suggesting they are a single species. Thus, I developed and optimized 14 microsatellite loci that amplify both A. maculatum s. s. and A. maculatum s. l. These novel microsatellite markers can be used in future analyses of A. maculatum s. l. and A. maculatum s. s. to further test for conspecificity between the two. I also investigated the genetic relationships within geographically distinct R. parkeri strains through development and implementation of a multi-locus sequence typing analysis. I showed that while there is no consistent genetic delineation of strains isolated from A. maculatum s. l. versus A. maculatum s. s., there is a subset of R. parkeri strains from A. maculatum s. l. that appear to represent an intermediate genotype between the North and South American strains. While the biological causes for these results are not immediately clear, coevolution of R. parkeri and A. maculatum s. l. may account for the detection of the intermediate genotype only found in association with A. maculatum s. l.

Tick-borne diseases are caused by a group of pathogenic microorganisms which are transmitted between animal and human population by vector which is most frequently tick. Evaluation of danger and perils of these diseases is important due to prevention and monitoring of current situation development. The most common tick-borne diseases in the Czech Republic are borreliosis, tick-borne encephalitis and ehrlichiosis. Rarely can we encounter bartonellosis, babesiosis, rickettsiosis and tularemia. All these diseases can have serious consequences and in critical cases they can result in death of the infected person. One of the basic and the most important of preventive measures which lower the risk of the infection by any tick-borne disease is prevention of tick encounter and eventually vaccination. Due to continual global warming we can expect that in near future ticks will spread even to locations which have been so far not suitable for their development. We can expect that we will even more frequently encounter tick-borne diseases - including diseases which were formerly not found in our territory or were very rare. As a part of health education it will be needed more to get known basic information of tick-borne diseases and their prevention. Different educational centres are an ideal place for...

Este estudo objetivou estudar os carrapatos e a infecção por patógenos, e sua correlação com os vertebrados desta região entre 10/2007 e 09/2008 foram realizadas mensalmente doze visitas a uma área de floresta ombrófila densa da Amazônica na Estação Ecológica de Samuel. Foram coletados, 60 aves, 36 mamíferos, 14 répteis e 11 anfíbios. Em vida livre foram realizadas 80 coletas de carrapatos em um total de 39.600m em cerca de 2.640min (44h) e coletados 265 carrapatos adultos de quatro espécies, sendo elas: A. scalpturatum (81), A. latepunctatum (84), A. oblongogutattum (18), A. naponense (69) e 597 ninfas de Amblyomma sp. Dos 104 adultos (11,8% do total de carrapatos) foram testados para Anaplasmataceae, obtive-se 27 (25,9%) positivos e mais 36 adultos (total de 140) e 11 carrapatos foram positivos (1) A. scalpturatum, (4) A. latepunctatum, (3) A. naponense. É notável o impacto da hidrelétrica sobre a fauna de pequenos mamíferos. / This study was aimed to analyze the ticks and the pathogenic infections, and their correlation with the vertebrates of such a region from October 2007 to September 2008, 12 surveys were monthly carried out at the Samuel Ecological Station in an Amazonian dense ombrophilous forest. They were collected from 60 birds, 36 mammals, 14 reptiles, and 11 amphibians. Eighty(80) collections of free-living ticks were carried out within an area of about 39.000 meters, during 2.640 minutes (44 hours), and 265 adult ticks or four species were picked up as following: 81 A.scalpturatum, 84 A. latepunctatum, 18 A. oblongogutattum, 69 A. naponense , and 597 Amblyomma sp. nymphs. 104 the adults, which accounted for 11.8% of total of ticks collected, were tested for Anaplasmataceae, and 27 (25.9%) were positive. In the Rickettsia spp. sample, additionally to the above mentioned 104 ticks tested, 36 adult ticks (out of a total of 140) were positive. It is noteworthy the impact caused by the hydropower plant on the small mammal fauna.

Este estudo objetivou estudar os carrapatos e a infecção por patógenos, e sua correlação com os vertebrados desta região entre 10/2007 e 09/2008 foram realizadas mensalmente doze visitas a uma área de floresta ombrófila densa da Amazônica na Estação Ecológica de Samuel. Foram coletados, 60 aves, 36 mamíferos, 14 répteis e 11 anfíbios. Em vida livre foram realizadas 80 coletas de carrapatos em um total de 39.600m em cerca de 2.640min (44h) e coletados 265 carrapatos adultos de quatro espécies, sendo elas: A. scalpturatum (81), A. latepunctatum (84), A. oblongogutattum (18), A. naponense (69) e 597 ninfas de Amblyomma sp. Dos 104 adultos (11,8% do total de carrapatos) foram testados para Anaplasmataceae, obtive-se 27 (25,9%) positivos e mais 36 adultos (total de 140) e 11 carrapatos foram positivos (1) A. scalpturatum, (4) A. latepunctatum, (3) A. naponense. É notável o impacto da hidrelétrica sobre a fauna de pequenos mamíferos. / This study was aimed to analyze the ticks and the pathogenic infections, and their correlation with the vertebrates of such a region from October 2007 to September 2008, 12 surveys were monthly carried out at the Samuel Ecological Station in an Amazonian dense ombrophilous forest. They were collected from 60 birds, 36 mammals, 14 reptiles, and 11 amphibians. Eighty(80) collections of free-living ticks were carried out within an area of about 39.000 meters, during 2.640 minutes (44 hours), and 265 adult ticks or four species were picked up as following: 81 A.scalpturatum, 84 A. latepunctatum, 18 A. oblongogutattum, 69 A. naponense , and 597 Amblyomma sp. nymphs. 104 the adults, which accounted for 11.8% of total of ticks collected, were tested for Anaplasmataceae, and 27 (25.9%) were positive. In the Rickettsia spp. sample, additionally to the above mentioned 104 ticks tested, 36 adult ticks (out of a total of 140) were positive. It is noteworthy the impact caused by the hydropower plant on the small mammal fauna.

Little is understood about off-host behavior and ecology of immature Amblyomma maculatum Koch (Gulf Coast tick). A more complete understanding of this tick is essential to protect human and animal health. My research focused on seasonality and distribution of immatures in Mississippi, potential suitability of some insect and human hosts to larvae, and aspects of nymphal questing behavior. A single larva was collected (third off-host collection reported) when sampling A. maculatum habitat using a novel device. Collection of this larva in November expands the stage’s known seasonality and confirmed a prediction concerning seasonality of larval A. maculatum. Low frequency of immatures (8.3%) confirmed that they’re incredibly difficult to collect off-host. Nymphal collections peaked in March, and known seasonality was extended for both nymphs and adults. I examined known records, elucidating seasonality and distribution of A. maculatum in Mississippi. Either multiple generations per year or diapause are responsible for observed bi-modal distribution of immature collections. Additionally, I compiled the most extensive host record of immature A. maculatum in Mississippi and investigated seasonality patterns using USDA plant hardiness zones. I compiled the most complete record of ticks found on arthropods. Amblyomma americanum and A. maculatum were both confirmed to crawl onto arthropods, giving support to occasional, unintentional dispersal by phoresy. There was no conclusive evidence that larval A. maculatum feed on arthropods, however data supported feeding by larval A. americanum. These results have interesting implications regarding evolution of pathogens/endosymbionts. I provided the first evidence that larval A. maculatum can attach to humans. Rickettsia parkeri, a human pathogen transmitted by this species has recently been shown to be capable of transovarial transmission. Therefore, larval A. maculatum may provide another avenue of transmission. I have demonstrated that A. maculatum are difficult to collect off-host in part because they prefer to quest low to the ground. In choice studies, 5-cm-tall stems were most likely to be occupied by nymphs released into an array of stems. Low vapor pressure deficit encouraged questing, while higher VPD and warmer temperature increased questing height. These results may have implications in understanding host-seeking behavior in other tick species as well.