The cohort Astigmatina is divided in two major groups: Psoroptidia, composed mainly by feather and fur mites, and Non-psoroptidia, a dominant component of the acarofauna in ephemeral habitats. In these environments Astigmatina usually are saprophages or feed on fungi or bacteria. Astigmatina protonymphs undergo a complete reorganization of the body structure leading to the production of heteromorphic deutonymphs, generally specialized for dispersion through phoresy using arthropods and vertebrates as phoronts. Although most Astigmatina occur in natural environments, some species live in anthropic environments, such as food deposits, where some of them became pests; some Astigmatina infest subterraneous plant organs. Despite their economic and ecological importance, studies on the diversity and taxonomy of Astigmatina in Brazil have been rare over the last decades. The general objective of this thesis was to collaborate to the knowledge of the diversity and to evaluate the potential practical uses of these mites in Brazil. For this, new genera and species were described, method for rearing dust mites was studied and the efficiency of Astigmatina as prey for edaphic predators was evaluated. A new species of Thyreophagus (Astigmatina: Acaridae) was described based on specimens collected in Brazil, the association of three other species of this genus with stored food was reviewed and a key to all species of this genus was prepared. The genus Neotropacarus (Astigmatina: Acaridae), commonly found on plant leaves, was reviewed with the redescription of two species and description of new species collected in Brazil and from the Philippines. Two new genera and seven new species of Acaridae associated with the bee family Apidae was described and a key to Acaridae genera in subfamily Horstiinae was prepared. Several species of Astigmatina were evaluated as prey for predatory mites Stratiolaelaps scimitus (Womersley) (Mesostigmata: Laelapidae) and Protogamasellopsis zaheri Abo-Shnaf, Castilho and Moraes (Mesostigmata: Rhodacaridae), which oviposited on all evaluated astigmatids, with Tyrophagus putrescentiae (Schrank) and Aleuroglyphus ovatus (Tropeau) (Acaridae) being the most suitable prey. Seven foods and two development period, 30 and 60 days, after the introduction of 400 females of two important dust mite species, Blomia tropicalis van Bronswijk, de Cock e Oshima and Dermatophagoides pteronyssinus (Trouessart) were evaluate. With the most suitable foods, the population growth were higher than 20.2 and 15.3 for B. tropicalis and D. pteronyssinus, respectively. / A coorte Astigmatina é dividida em dois grandes grupos: Psoroptidia, composto majoritariamente por ácaros de pena e pelos, e Não-Psoroptidia, componente dominante da acarofauna de habitats efêmeros. Nestes ambientes, os Astigmatina geralmente são saprófagos ou se alimentam de fungos e bactérias. Protoninfas de Astigmatina passam por uma completa reorganização da estrutura corporal levando à produção de deutoninfas heteromórficas geralmente especializadas para dispersão por forese utilizando artrópodes e vertebrados como forontes. Apesar de a maioria dos Astigmatina ocorrer em ambientes naturais, algumas espécies passaram a ocupar ambientes antrópicos, como depósitos de alimentos, onde algumas se tornaram pragas; alguns Astigmatina infestam órgãos subterrâneos de plantas. A despeito de sua importância econômica e ecológica, estudos sobre a diversidade e taxonomia dos Astigmatina no Brasil têm sido raros nas últimas décadas. O objetivo geral desta tese foi colaborar para o conhecimento da diversidade e avaliar o potencial de uso prático de espécies Astigmatina no Brasil. Para isso, novos gêneros e espécies foram descritos, métodos para criação de ácaros de poeira foram estudados e a eficiência de Astigmatina como presas para ácaros predadores edáficos foi avaliada. Uma nova espécie de Thyreophagus (Astigmatina: Acaridae) foi descrita com base em espécimes coletados no Brasil, uma revisão sobre três outras espécies deste gênero associadas com alimentos armazenados foi realizada e uma chave para todas as espécies deste gênero foi elaborada. O gênero Neotropacarus (Astigmatina: Acaridae), comumente associado a folhas de plantas, foi revisado, com redescrição de duas espécies e descrição de novas espécies coletadas no Brasil e nas Filipinas. Dois novos gêneros e sete novas espécies de Acaridae associados à família de abelha Apidae foram descritos e uma chave para os gêneros da subfamília Horstiinae foi elaborada. Diversas espécies de Astigmatina foram avaliadas como presas para os ácaros predadores Stratiolaelaps scimitus (Womersley) (Mesostigmata: Laelapidae) e Protogamasellopsis zaheri Abo-Shnaf, Castilho e Moraes (Mesostigmata: Rhodacaridae), que ovipositaram em todas os Astigmatina avaliados, sendo Tyrophagus putrescentiae (Schrank) e Aleuroglyphus ovatus (Tropeau) (Acaridae) as presas mais promissoras. Sete alimentos e dois períodos de desenvolvimento, 30 e 60 dias, após inoculação de 400 fêmeas de duas espécies importantes na poeira residencial, Blomia tropicalis van Bronswijk, de Cock e Oshima e Dermatophagoides pteronyssinus (Trouessart) foram avaliados. Com os alimentos mais adequados, o crescimento populacional nas colônias foram maiores que 20.2 e 15.3 para B. tropicalis e D. pteronyssinus, respectivamente.

The cohort Astigmatina is divided in two major groups: Psoroptidia, composed mainly by feather and fur mites, and Non-psoroptidia, a dominant component of the acarofauna in ephemeral habitats. In these environments Astigmatina usually are saprophages or feed on fungi or bacteria. Astigmatina protonymphs undergo a complete reorganization of the body structure leading to the production of heteromorphic deutonymphs, generally specialized for dispersion through phoresy using arthropods and vertebrates as phoronts. Although most Astigmatina occur in natural environments, some species live in anthropic environments, such as food deposits, where some of them became pests; some Astigmatina infest subterraneous plant organs. Despite their economic and ecological importance, studies on the diversity and taxonomy of Astigmatina in Brazil have been rare over the last decades. The general objective of this thesis was to collaborate to the knowledge of the diversity and to evaluate the potential practical uses of these mites in Brazil. For this, new genera and species were described, method for rearing dust mites was studied and the efficiency of Astigmatina as prey for edaphic predators was evaluated. A new species of Thyreophagus (Astigmatina: Acaridae) was described based on specimens collected in Brazil, the association of three other species of this genus with stored food was reviewed and a key to all species of this genus was prepared. The genus Neotropacarus (Astigmatina: Acaridae), commonly found on plant leaves, was reviewed with the redescription of two species and description of new species collected in Brazil and from the Philippines. Two new genera and seven new species of Acaridae associated with the bee family Apidae was described and a key to Acaridae genera in subfamily Horstiinae was prepared. Several species of Astigmatina were evaluated as prey for predatory mites Stratiolaelaps scimitus (Womersley) (Mesostigmata: Laelapidae) and Protogamasellopsis zaheri Abo-Shnaf, Castilho and Moraes (Mesostigmata: Rhodacaridae), which oviposited on all evaluated astigmatids, with Tyrophagus putrescentiae (Schrank) and Aleuroglyphus ovatus (Tropeau) (Acaridae) being the most suitable prey. Seven foods and two development period, 30 and 60 days, after the introduction of 400 females of two important dust mite species, Blomia tropicalis van Bronswijk, de Cock e Oshima and Dermatophagoides pteronyssinus (Trouessart) were evaluate. With the most suitable foods, the population growth were higher than 20.2 and 15.3 for B. tropicalis and D. pteronyssinus, respectively. / A coorte Astigmatina é dividida em dois grandes grupos: Psoroptidia, composto majoritariamente por ácaros de pena e pelos, e Não-Psoroptidia, componente dominante da acarofauna de habitats efêmeros. Nestes ambientes, os Astigmatina geralmente são saprófagos ou se alimentam de fungos e bactérias. Protoninfas de Astigmatina passam por uma completa reorganização da estrutura corporal levando à produção de deutoninfas heteromórficas geralmente especializadas para dispersão por forese utilizando artrópodes e vertebrados como forontes. Apesar de a maioria dos Astigmatina ocorrer em ambientes naturais, algumas espécies passaram a ocupar ambientes antrópicos, como depósitos de alimentos, onde algumas se tornaram pragas; alguns Astigmatina infestam órgãos subterrâneos de plantas. A despeito de sua importância econômica e ecológica, estudos sobre a diversidade e taxonomia dos Astigmatina no Brasil têm sido raros nas últimas décadas. O objetivo geral desta tese foi colaborar para o conhecimento da diversidade e avaliar o potencial de uso prático de espécies Astigmatina no Brasil. Para isso, novos gêneros e espécies foram descritos, métodos para criação de ácaros de poeira foram estudados e a eficiência de Astigmatina como presas para ácaros predadores edáficos foi avaliada. Uma nova espécie de Thyreophagus (Astigmatina: Acaridae) foi descrita com base em espécimes coletados no Brasil, uma revisão sobre três outras espécies deste gênero associadas com alimentos armazenados foi realizada e uma chave para todas as espécies deste gênero foi elaborada. O gênero Neotropacarus (Astigmatina: Acaridae), comumente associado a folhas de plantas, foi revisado, com redescrição de duas espécies e descrição de novas espécies coletadas no Brasil e nas Filipinas. Dois novos gêneros e sete novas espécies de Acaridae associados à família de abelha Apidae foram descritos e uma chave para os gêneros da subfamília Horstiinae foi elaborada. Diversas espécies de Astigmatina foram avaliadas como presas para os ácaros predadores Stratiolaelaps scimitus (Womersley) (Mesostigmata: Laelapidae) e Protogamasellopsis zaheri Abo-Shnaf, Castilho e Moraes (Mesostigmata: Rhodacaridae), que ovipositaram em todas os Astigmatina avaliados, sendo Tyrophagus putrescentiae (Schrank) e Aleuroglyphus ovatus (Tropeau) (Acaridae) as presas mais promissoras. Sete alimentos e dois períodos de desenvolvimento, 30 e 60 dias, após inoculação de 400 fêmeas de duas espécies importantes na poeira residencial, Blomia tropicalis van Bronswijk, de Cock e Oshima e Dermatophagoides pteronyssinus (Trouessart) foram avaliados. Com os alimentos mais adequados, o crescimento populacional nas colônias foram maiores que 20.2 e 15.3 para B. tropicalis e D. pteronyssinus, respectivamente.

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2018-2019. / En se nourrissant de l’hémolymphe et des corps gras de l’abeille domestique (Apis mellifera L.) et en lui transmettant de nombreux virus, l’acarien parasite Varroa destructor (Acari : varroidae) constitue la principale cause de mortalité des colonies d’abeilles. Les traitements chimiques présentement utilisés pour lutter contre le varroa comportent plusieurs désavantages, tels que le développement de résistance de l’acarien aux acaricides de synthèse et une toxicité variable pour l’abeille. Via l’utilisation d’ennemis naturels du parasite, la lutte biologique pourrait représenter une avenue durable et sécuritaire pour la santé des colonies. L’objectif principal de cette étude était de tester l’efficacité de l’acarien prédateur Stratiolaelaps scimitus (Acari : Lealapidae) comme moyen de lutte biologique contre le varroa. Une étude du comportement alimentaire du prédateur a d’abord été réalisée afin d’évaluer le risque de prédation du couvain d’abeille (oeufs, larves et pupes) par S. scimitus, ainsi que son potentiel de prédation envers les varroas phorétiques (se trouvant sur le corps des abeilles adultes). Des essais in vivo ont ensuite permis d’évaluer l’efficacité de deux doses d’introduction du prédateur (6 250 ou 12 500 acariens/colonie) à contrôler les populations de varroa dans les colonies d’abeilles en septembre (en comparaison avec l’acaricide biologique Thymovar®) et en novembre (en comparaison avec l’acide oxalique). Bien que S. scimitus soit capable de s’alimenter sur tous les stades de développement de l’abeille en laboratoire, nos résultats suggèrent que le prédateur ne représente pas une menace pour le couvain lorsqu’il est introduit dans la colonie. Par contre, nos résultats démontrent que le prédateur n’est pas en mesure de contrôler les populations de varroas dans les colonies d’abeilles sous les conditions testées, c’est-à-dire lorsqu’il est introduit à l’automne selon la dose actuellement recommandée par certains distributeurs. Cette inefficacité est probablement liée à l’incapacité du prédateur à s’attaquer aux varroas phorétiques. / By feeding on the hemolymph and fat bodies of the honey bee (Apis mellifera L.) and transmitting many viruses, the parasitic mite Varroa destructor (Acari: varroidae) is considered as the main cause of honey bee colony losses. The use of chemicals in varroa control shows many disadvantages, such as the development of mite resistance to synthetic acaricides and a variable toxicity for bees. Through the use of natural enemies, the biological control of varroa mites could represent a sustainable and safe avenue for colony health. The main objective of this study was to test the effectiveness of the predatory mite Stratiolaelaps scimitus (Acari: Lealapidae) as a means of biological control against varroa mites. A study of the predator’s feeding behaviour was first performed to evaluate the risk of predation of bee brood (eggs, larvae and pupae) by S. scimitus, as well as its predation potential upon phoretic varroa mites (varroa parasitizing adult bees). In vivo trials were then carried out to evaluate the effectiveness of two predator introduction rates (6,250 or 12,500 mites / colony) to control varroa populations in honey bee colonies in September (compared to the organic acaricide Thymovar®) and in November (compared to oxalic acid). Although S. scimitus is able to feed on all bee developmental stages in the laboratory, our results suggest that the predator does not pose a threat to the bee brood when introduced into the colony. On the other hand, our results demonstrate that the predator is not able to control varroa populations in bee colonies under the tested conditions, that is, when it is introduced in fall according to the rate currently recommended by some biocontrol suppliers. This ineffectiveness is probably related to the inability of the predator to attack phoretic varroa mites.

Tableau d'honneur de la FÉSP / En se nourrissant de l’hémolymphe et des corps gras de l’abeille domestique (Apis mellifera L.) et en lui transmettant de nombreux virus, l’acarien parasite Varroa destructor (Acari : varroidae) constitue la principale cause de mortalité des colonies d’abeilles. Les traitements chimiques présentement utilisés pour lutter contre le varroa comportent plusieurs désavantages, tels que le développement de résistance de l’acarien aux acaricides de synthèse et une toxicité variable pour l’abeille. Via l’utilisation d’ennemis naturels du parasite, la lutte biologique pourrait représenter une avenue durable et sécuritaire pour la santé des colonies. L’objectif principal de cette étude était de tester l’efficacité de l’acarien prédateur Stratiolaelaps scimitus (Acari : Lealapidae) comme moyen de lutte biologique contre le varroa. Une étude du comportement alimentaire du prédateur a d’abord été réalisée afin d’évaluer le risque de prédation du couvain d’abeille (oeufs, larves et pupes) par S. scimitus, ainsi que son potentiel de prédation envers les varroas phorétiques (se trouvant sur le corps des abeilles adultes). Des essais in vivo ont ensuite permis d’évaluer l’efficacité de deux doses d’introduction du prédateur (6 250 ou 12 500 acariens/colonie) à contrôler les populations de varroa dans les colonies d’abeilles en septembre (en comparaison avec l’acaricide biologique Thymovar®) et en novembre (en comparaison avec l’acide oxalique). Bien que S. scimitus soit capable de s’alimenter sur tous les stades de développement de l’abeille en laboratoire, nos résultats suggèrent que le prédateur ne représente pas une menace pour le couvain lorsqu’il est introduit dans la colonie. Par contre, nos résultats démontrent que le prédateur n’est pas en mesure de contrôler les populations de varroas dans les colonies d’abeilles sous les conditions testées, c’est-à-dire lorsqu’il est introduit à l’automne selon la dose actuellement recommandée par certains distributeurs. Cette inefficacité est probablement liée à l’incapacité du prédateur à s’attaquer aux varroas phorétiques. / By feeding on the hemolymph and fat bodies of the honey bee (Apis mellifera L.) and transmitting many viruses, the parasitic mite Varroa destructor (Acari: varroidae) is considered as the main cause of honey bee colony losses. The use of chemicals in varroa control shows many disadvantages, such as the development of mite resistance to synthetic acaricides and a variable toxicity for bees. Through the use of natural enemies, the biological control of varroa mites could represent a sustainable and safe avenue for colony health. The main objective of this study was to test the effectiveness of the predatory mite Stratiolaelaps scimitus (Acari: Lealapidae) as a means of biological control against varroa mites. A study of the predator’s feeding behaviour was first performed to evaluate the risk of predation of bee brood (eggs, larvae and pupae) by S. scimitus, as well as its predation potential upon phoretic varroa mites (varroa parasitizing adult bees). In vivo trials were then carried out to evaluate the effectiveness of two predator introduction rates (6,250 or 12,500 mites / colony) to control varroa populations in honey bee colonies in September (compared to the organic acaricide Thymovar®) and in November (compared to oxalic acid). Although S. scimitus is able to feed on all bee developmental stages in the laboratory, our results suggest that the predator does not pose a threat to the bee brood when introduced into the colony. On the other hand, our results demonstrate that the predator is not able to control varroa populations in bee colonies under the tested conditions, that is, when it is introduced in fall according to the rate currently recommended by some biocontrol suppliers. This ineffectiveness is probably related to the inability of the predator to attack phoretic varroa mites.