Thesis (M.Sc.)(Zoology)--University of Pretoria, 2006. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (M.S. in entomology)--Washington State University, December 2008. / Title from PDF title page (viewed on Mar. 4, 2009). "Department of Entomology." Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 42-52).

This work is focused on the study of physiology and proteome of the the mite Varroa destructor and on comparison with the honeybee Apis mellifera. Varroa is currently a major problem for beekeeping, because infects most of the colonies. The control of the mite can not be done without residues both in the hive and for example in the honey or other resources used by the man. Another problem can also be the simultaneously discussed issue of the connection with the Colony Collapse Disorder. The internal anatomy of V. destructor was studied by using paraffin histology. On histological sections stained using hematoxylin and PAS was possible to observe the mite digestive system, but also egg, ovaries or brain. The primary aim of this study was to identify the proteins of mite V. destructor and bee A. mellifera as a host of this parasite. For the electrophoretic separation was used two- dimensional gel electrophoresis, where the second dimension was carried out using 12% and 15% SDS-PAGE. The most abundant spots were selected for analysis using MALDI TOF/TOF mass spectrometry. The most abundant protein identified in samples of V. destructor was hexamerin, arginine kinase or hemelipoglycoprotein precursor. Hexamerins were also identified as the major proteins in the pupae samples. On the contrary the main...

Aspects concerning the bionomics of the parasitic honey bee brood mite, Varroa jacobsoni Oudemans were investigated. Mite mortality is great during the winter season when the host colony is not rearing brood, appearing to be independent of the mortality of its host. In winter period, no significant association between the number of dead mites and the number of dead adult workers was observed. It appears that the mites are dying by factors other than the host death. Drifting drones facilitate the horizontal transmission of Varroa jacobsoni mites between colonies, especially in modern beekeeping in which managed colonies are kept similarly hived and close together. A great tendency of drones to drift among colonies was observed. A significant correlation was found in the rate of mites per drones and the number of drones in the colonies. It was concluded that the transmission of Varroa jacobsoni among colonies via drifting drones is a common mechanism for the transmission of mites. The relationship between mite load and the size of the honey bee brood host was investigated. The data showed significant statistical differences between the infestation rate of the mite that is, number of female mites per infested pupae and the size of the worker brood nest of its host. With a high number of worker cells in the colony, the mite load is lowered. Feeding activities of V. jacobsoni causes a great impact on A. mellifera colony survival not only through physical damage caused by this mite but also through transmission of various entomopathogenic agents responsible for the outbreak of secondary diseases in the colony. I concluded that mites fed on adult bees during summer time. It appears that the frequency of mite feeding on adult bees at this time is low, suggesting that probably the mite feeds only for maintenance and survival rather than for reproduction. / Graduation date: 1997

Submitted by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2016-10-13T18:21:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Identificacao de virus que afetam apis mellifera.pdf: 2079239 bytes, checksum: 490f111cf7ddb616e9d3cc3373a5be07 (MD5) / Made available in DSpace on 2016-10-13T18:21:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Identificacao de virus que afetam apis mellifera.pdf: 2079239 bytes, checksum: 490f111cf7ddb616e9d3cc3373a5be07 (MD5) Previous issue date: 2014-04-30 / A apicultura é uma atividade de importância econômica e ambiental. O clima e a flora do Brasil somados à presença da abelha africanizada conferem um excelente potencial apícola. Entretanto, as abelhas são suscetíveis a uma variedade de doenças. Vários são os patógenos que podem acometer abelhas melíferas, sendo o foco deste trabalho a relação entre o ácaro Varroa destructor e os vírus que acometem abelhas. V. destructor é um ectoparasita, sendo a varroose, doença causada por este ácaro, responsável pela mortalidade de milhares de colônias de Apis mellifera em várias partes do mundo. Entretanto, os danos causados pela varroose variam com a raça de abelhas e condições climáticas. Embora o ácaro cause poucos danos nas colônias de abelhas africanizadas no Brasil, a coexistência deste ectoparasita com determinados tipos virais pode comprometer seriamente a saúde da colônia, uma vez que muitos destes vírus tem sua transmissão relacionada ao ectoparasita, apontando este como um vetor da infecção. Portanto, faz-se necessária a identificação de quais vírus estão associados ao ácaro e que, possivelmente, utilizam-se do ácaro como vetor. Dentro deste contexto, objetivamos verificar a existência de vírus associados ao ácaro V. destructor em espécimes coletadas em apiários de diferentes regiões do Rio Grande do Sul. Foram realizadas coletas de ácaros em apiários localizados em oito municípios gaúchos. A partir das amostras coletadas, foi realizada extração de RNA total e síntese de cDNA. O cDNA sintetizado foi submetido à PCR utilizando-se 9 pares de primers para detecção de vírus que afetam abelhas e um par de primers para controle endógeno. As amostras foram submetidas a eletroforese em gel de agarose. Identificou-se, em três apiários, a presença dos vírus SBV (Vírus da Cria Ensacada) e VDV-1 (Vírus Varroa destructor-1) associados ao ácaro V. destructor. Estes dados são inéditos uma vez que estudos semelhantes nunca foram realizados no Brasil ou em abelhas africanizadas e poderão servir de base no desenvolvimento de programas de controle deste parasita. / Beekeeping is an activity that has both economic and environmental importance. Brazil has excellent climate and flora for beekeeping, and alongside the presence of Africanized bee populations, it has great potential for apiculture. However, Apis mellifera bees are susceptible to a variety of diseases. There are several pathogens that can affect honeybees and the focus of this work is to assess the relationship between the Varroa destructor mite and viruses that affect bees in the state of Rio Grande do Sul. V. destructor is an ectoparasite and the disease caused by this mite may be responsible for the death of thousands of colonies of A. mellifera in several parts of the world. However, the damage caused by the varroa mite vary according to the race of the affected bees and weather conditions. Although the varroa mite cause little damage in colonies of Africanized bees in Brazil, the coexistence of this ectoparasite with certain types of viruses can seriously compromise the health of the colony, since many of these viruses use the mite for transmission, pointing this as a probable vector. Therefore, it is necessary to identify which viruses are associated with the mite and that possibly use it as vector. Within this context, the objective of this work is to verify the presence of viruses associated with the V. destructor mite in specimens collected in apiaries in different regions of Rio Grande do Sul. Mite collections were made in apiaries located in eight different cities in the state. Collected samples were subjected to total RNA extrection and cDNA synthesis was performed. The synthesized cDNA was subjected to PCR using nine primer pairs for detection of viruses affecting bee and one pair of primers for endogenous control. Amplified samples were subjected to electrophoresis on agarose gel. With this work, we have been able to identify in the presence of SBV and VDV-1 virus associated with V. destructor mite in three different apiaries. The obtained data are novel, since similar studies have never been conducted before in Brazil or using Africanized bee colonies, and could be used as basis in development of control strategies of this parasite.

The European honeybee (Apis mellifera) is a managed insect pollinator of global economic importance. Over the last few decades honeybees have been undergoing a major health crisis, with one of the biggest causes the parasitic mite, Varroa destructor and its role in changing the viral landscape of deformed wing virus (DWV), which consists of two major variants: DWV-A and DWV-B. Prior to the start of this project there was limited information known about the mechanisms behind the relationships between Varroa, DWV and honeybees. The overarching aim of this project was to further enhance our understanding of these complex relationships, focusing on the impact of Varroa DWV transmission and differences between the main DWV variants. One of the initial obstacles to understanding these complex interactions was the inability to accurately quantify DWV variants. Prior to the start of this project, there was a need for an accurate assay for the quantification of DWV-A, DWV-B and total DWV, allowing the role of both variants in viral transmission and establishment to be investigated. While primers did exist for DWV quantification, the majority did not distinguish between variants, or provide accurate levels of DWV. Given these challenges in variant detection, a new assay for the quantification of DWV-A, DWV-B and total DWV was designed and validated. The assay consists of an external plasmid standard with distinct sections, for the detection of variants and total DWV. This DWV variant plasmid assay was essential for further transmission studies in this project. DWV variant transmission was explored using a variety of different methods. A new in vitro feeding system was used, to allow investigations into Varroa DWV variant transmission in isolation. The feeding system utilises locust haemolymph, allowing changes in DWV transmission to be detected. In multiple feeding experiments significant changes in DWV transmission were detected. Significant changes in DWV composition within feeding Varroa were detected with decreased levels of DWV, and changing variant levels. Switches in variant composition within mites and transmission rates occurred during Varroa in vitro feeding. These variant switches occurred in both directions from DWV-A to DWV-B, and DWV-B to DWV-A dominance. These changes in mite variant composition corresponded to changes in levels of replicating strands. iv These changes in DWV transmission, composition and replicating strand detection were only seen due to the use of this in vitro feeding system. The in vitro work provided valuable information about Varroa variant transmission and composition changes during feeding but this is not a natural system. Honeybee pupae from a Varroa-free area with extremely low DWV titres provided the opportunity to investigate Varroa variant transmission and pupal DWV establishment. Over 96 hours total DWV levels underwent a 1339408X fold increase, within pupae following Varroa feeding, with a sharp increase after 12 hours, followed by a plateau after 60 hours. Within this time period, DWV-A underwent a similar increase, while DWV-B increased at a much slower rate (33X fold change). In contrast to the in vitro work, mite DWV levels did not decrease during feeding. The impact of natural Varroa cell infestation on L5 larvae was investigated, showing no significant effects between pupal total DWV levels and mite density, and DWV levels between infested and none-infested larvae. However, this lack of significance could be attributed to the use of L5 larvae, which had only undergone a maximum of 24 hours Varroa feeding within the cell. Additionally, the use of two drug treatments (ribavirin and hydroxyurea) to reduce DWV levels was explored. Both drug treatments were tested against Varroa and honeybees, using a variety of methods: immersion (Varroa), injections (honeybees) and feeding (both). While neither drug treatment resulted in consistent DWV decreases, some reduction in DWV levels were seen following Varroa soaking in drug solutions. A significant decrease in DWV was seen in honeybees following bolus and ad libitum feeding of drug treatments. Overall, information and insights have been gained regarding the complex relationship between Varroa, honeybees and DWV. A new DWV variant qPCR assay was developed and utilised in subsequent studies. DWV variant switches in both transmission rates and mite composition were found to occur in in vitro studies. Differences in DWV variant establishment within honeybees were detected following Varroa in vivo feeding, in low DWV pupae. Though the tested drug treatments did not affect DWV levels, this highlights the difficultly facing the establishment of any DWV treatment.

Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-07T22:33:38Z No. of bitstreams: 1 126110036.pdf: 2091532 bytes, checksum: 8020f2b19bedcc2aebd080e502846a88 (MD5) / Made available in DSpace on 2015-05-07T22:33:38Z (GMT). No. of bitstreams: 1 126110036.pdf: 2091532 bytes, checksum: 8020f2b19bedcc2aebd080e502846a88 (MD5) Previous issue date: 2014-04-30 / A apicultura é uma atividade de importância econômica e ambiental. O clima e a flora do Brasil somados à presença da abelha africanizada conferem um excelente potencial apícola. Entretanto, as abelhas são suscetíveis a uma variedade de doenças. Vários são os patógenos que podem acometer abelhas melíferas, sendo o foco deste trabalho a relação entre o ácaro Varroa destructor e os vírus que acometem abelhas. V. destructor é um ectoparasita, sendo a varroose, doença causada por este ácaro, responsável pela mortalidade de milhares de colônias de Apis mellifera em várias partes do mundo. Entretanto, os danos causados pela varroose variam com a raça de abelhas e condições climáticas. Embora o ácaro cause poucos danos nas colônias de abelhas africanizadas no Brasil, a coexistência deste ectoparasita com determinados tipos virais pode comprometer seriamente a saúde da colônia, uma vez que muitos destes vírus tem sua transmissão relacionada ao ectoparasita, apontando este como um vetor da infecção. Portanto, faz-se necessária a identificação de quais vírus estão associados ao ácaro e que, possivelmente, utilizam-se do ácaro como vetor. Dentro deste contexto, objetivamos verificar a existência de vírus associados ao ácaro V. destructor em espécimes coletadas em apiários de diferentes regiões do Rio Grande do Sul. Foram realizadas coletas de ácaros em apiários localizados em oito municípios gaúchos. A partir das amostras coletadas, foi realizada extração de RNA total e síntese de cDNA. O cDNA sintetizado foi submetido à PCR utilizando-se 9 pares de primers para detecção de vírus que afetam abelhas e um par de primers para controle endógeno. As amostrasforam submetidas a eletroforese em gel de agarose. Identificou-se, em três apiários, a presença dos vírus SBV (Vírus da Cria Ensacada) e VDV-1 (Vírus Varroa destructor-1) associados ao ácaro V. destructor. Estes dados são inéditos uma vez que estudos semelhantes nunca foram realizados no Brasil ou em abelhas africanizadas e poderão servir de base no desenvolvimento de programas de controle deste parasita. / Beekeeping is an activity that has both economic and environmental importance. Brazil has excellent climate and flora for beekeeping, and alongside the presence of Africanized bee populations, it has great potential for apiculture. However, Apis mellifera bees are susceptible to a variety of diseases. There are several pathogens that can affect honeybees and the focus of this work is to assess the relationship between the Varroa destructor mite and viruses that affect bees in the state of Rio Grande do Sul. V. destructor is an ectoparasite and the disease caused by this mite may be responsible for the death of thousands of colonies of A. mellifera in several parts of the world. However, the damage caused by the varroa mite vary according to the race of the affected bees and weather conditions. Although the varroa mite cause little damage in colonies of Africanized bees in Brazil, the coexistence of this ectoparasite with certain types of viruses can seriously compromise the health of the colony, since many of these viruses use the mite for transmission, pointing this as a probable vector. Therefore, it is necessary to identify which viruses are associated with the mite and that possibly use it as vector. Within this context, the objective of this work is to verify the presence of viruses associated with the V. destructor mite in specimens collected in apiaries in different regions of Rio Grande do Sul. Mite collections were made in apiaries located in eight different cities in the state. Collected samples were subjected to total RNA extrection and cDNA synthesis was performed. The synthesized cDNA was subjected to PCR using nine primer pairs fordetection of viruses affecting bee and one pair of primers for endogenous control. Amplified samples were subjected to electrophoresis on agarose gel. With this work, we have been able to identify in the presence of SBV and VDV-1 virus associated with V. destructor mite in three different apiaries. The obtained data are novel, since similar studies have never been conducted before in Brazil or using Africanized bee colonies, and could be used as basis in development of control strategies of this parasite.

Submitted by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2016-11-30T18:54:51Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Identificação de vírus que afetam apis mellifera associados ao ácaro ectoparasita varroa destructor em apiários do Rio Grande do Sul.pdf: 2079239 bytes, checksum: 490f111cf7ddb616e9d3cc3373a5be07 (MD5) / Made available in DSpace on 2016-11-30T18:54:51Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Identificação de vírus que afetam apis mellifera associados ao ácaro ectoparasita varroa destructor em apiários do Rio Grande do Sul.pdf: 2079239 bytes, checksum: 490f111cf7ddb616e9d3cc3373a5be07 (MD5) Previous issue date: 2014-04-30 / A apicultura é uma atividade de importância econômica e ambiental. O clima e a flora do Brasil somados à presença da abelha africanizada conferem um excelente potencial apícola. Entretanto, as abelhas são suscetíveis a uma variedade de doenças. Vários são os patógenos que podem acometer abelhas melíferas, sendo o foco deste trabalho a relação entre o ácaro Varroa destructor e os vírus que acometem abelhas. V. destructor é um ectoparasita, sendo a varroose, doença causada por este ácaro, responsável pela mortalidade de milhares de colônias de Apis mellifera em várias partes do mundo. Entretanto, os danos causados pela varroose variam com a raça de abelhas e condições climáticas. Embora o ácaro cause poucos danos nas colônias de abelhas africanizadas no Brasil, a coexistência deste ectoparasita com determinados tipos virais pode comprometer seriamente a saúde da colônia, uma vez que muitos destes vírus tem sua transmissão relacionada ao ectoparasita, apontando este como um vetor da infecção. Portanto, faz-se necessária a identificação de quais vírus estão associados ao ácaro e que, possivelmente, utilizam-se do ácaro como vetor. Dentro deste contexto, objetivamos verificar a existência de vírus associados ao ácaro V. destructor em espécimes coletadas em apiários de diferentes regiões do Rio Grande do Sul. Foram realizadas coletas de ácaros em apiários localizados em oito municípios gaúchos. A partir das amostras coletadas, foi realizada extração de RNA total e síntese de cDNA. O cDNA sintetizado foi submetido à PCR utilizando-se 9 pares de primers para detecção de vírus que afetam abelhas e um par de primers para controle endógeno. As amostras foram submetidas a eletroforese em gel de agarose. Identificou-se, em três apiários, a presença dos vírus SBV (Vírus da Cria Ensacada) e VDV-1 (Vírus Varroa destructor-1) associados ao ácaro V. destructor. Estes dados são inéditos uma vez que estudos semelhantes nunca foram realizados no Brasil ou em abelhas africanizadas e poderão servir de base no desenvolvimento de programas de controle deste parasita.

Zugl.: Hohenheim, Univ., Diss., 2006