Diversity and predatory potential of Gamasina soil mites (Mesostigmata) from the Caatinga biome and construction of databases for Ologamasidae and Rhodacaridae (Mesostigmata: Rhodacaroidea)

• Ano de defesa: 2025
• Autor(a) principal: Barros, Ávyla Régia de Albuquerque
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Acarologia; Acarology; Ácaros predadores; Biological control; Brasil; Brazil; Controle biológico; Predatory mites; Taxonomia; Taxonomy
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11146/tde-13052025-114253/

The Caatinga biome occupies an area equivalent to approximately 10% of the Brazilian territory, while constituting an ecosystem exclusively found in this country. Although of great socioeconomic importance, there is little ecological information available about this ecosystem. Human disturbances of the Caatinga have resulted in considerable losses of biodiversity. However, ecological damage is difficult to measure, mainly due to lacking basic information. Studies on groups of invertebrates in this region are scarce, especially those that inhabit the soil. The order Mesostigmata generally constitute the second most abundant soil mite group. Within that order, the Gamasina cohort includes many species of predators potentially useful as biological control agents of pest organisms, that can also be used as ecological bioindicators within varied ecosystems. This study aimed to evaluate the diversity of soil mites, focusing on Gamasina, in cultivated and natural areas of the Caatinga to estimate the impact of agricultural practices on these mites; use molecular tools to characterize common groups of soil Gamasina; describe four new species for science and redescribe one species; verify the potential of two predatory mites for the control of pests that live in the soil or spend part of their life cycle in this environment, as well as to develop a database on the world distribution of Ologamasidae and Rhodacaridae. In the diversity study carried out in Paulo Afonso, Bahia, the Gamasina were represented by 36 morphospecies from 24 genera, of which ten species are new to science. Ascidae was the most numerous family, representing about 46% of the Gamasina collected, followed by Laelapidae and Rhodacaridae (≅21% each). The most abundant species were Protogamasellus mica (Athias-Henriot) (Ascidae) (562) and a new species of Multidentorhodacarus (Rhodacaridae) (411). In the diversity study carried out in Bom Conselho, Pernambuco, the Gamasina were represented by 73 morphospecies from 32 genera, of which 24 morphospecies and one genus are new to science. Ascidae was again the most abundant family, representing approximately 44% of the Gamasina, followed by Rhodacaridae (19%) and Laelapidae (14%). The most abundant species were P. mica (595) and Multidenorhodacarus aegypticus Abo-Shnaf, Castilho & Moraes (270). The molecular study indicated low intraspecific variation within the same biome, while among specimens from populations of different biomes (Amazon Rainforest, Atlantic Forest, Caatinga, Cerrado and Pantanal), cases of higher polymorphism were revealed. Furthermore, Endopodoseius n. sp., Cheiroseius n. sp., Lasioseius biota Barros & Castilho and Proctolaelaps n. sp., were described, and the latter also used molecular markers; Lasioseius meridionalis Chant, was redescribed. For the predation test, a female of the ascid Gamasellodes lavafesii Castro, Azevedo & Castilho or the laelapid Cosmolaelaps mediocuspis (Karg) preyed daily on a mean of 240-245 second-stage juveniles (J2) of root-knot nematode Meloidogyne javanica (Treub) (Heteroderidae). For the databases, information about world distributions and habitats were collected from the world literature on the 472 and 164 species currently considered to belong to Ologamasidae and Rhodacaridae, respectively. Given the increasing threats to the Caatinga, studies of this type are essential to highlight its biodiversity and the ecosystem services that can be provided by Gamasina soil mites, contributing to the appreciation and conservation of this unique biome.