The production of apples (Malus domestica: Rosaceae) in Brazil is concentrated in three states in the southern region of the country. This crop is of great economic importance for the region, and is usually susceptible to infestations of mite populations. However, recent surveys of mite species associated to apples are scarce. The aim of the present study was to fill this void by analyzing species abundance and composition on three apple cultivars in the southern region of Brazil. The survey was carried out in the states of Rio Grande do Sul (RS), Santa Catarina (SC), and Paraná (PR). A total of 94 apple orchards were evaluated (43 Gala, 40 Fuji and 11 Eva), in 19 municipalities. Twenty plants were sampled from each orchard in March 2019, with four leaves collected from each plant, thus totaling 80 leaves/orchard. Mites were screened and identified in the Laboratório de Acarologia of Universidade do Vale do Taquari - UNIVATES. Data were analyzed using the R software with mixed generalized linear models, non-metric multidimensional scaling, and PERMANOVA. A total of 4,909 mite specimens were identified, belonging to eight species and six genera, of which 1,833 were classified as phytophagous, 1,758 as predators, and 1,318 as generalists. The most abundant phytophagous species was Aculus schlechtendali (33.55%), followed by the predator Neoseiulus californicus (33.14%) and by the generalist Tarsonemus (Tarsonemus) sp. (23.99%). Abundance was similar between Eva and Fuji cultivars. However, these cultivars differed in composition, as did Eva and Gala. The mean number of mites found in Santa Catarina and Rio Grande do Sul was similar, although Paraná had a higher number. Species composition also differed among the three states evaluated. Considering the importance of the apple production in the southern region of Brazil, studies on species composition and abundance are important, aiming to monitor potential damage-causing organisms to the crop and associated predators.

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Many studies have reported that the interaction between water mite larvae and their Odonata hosts affects mating success, flight, and longevity. Males and females of Odonata species collected in the steppes and coastal plains (Pampa Biome) of Rio Grande do Sul were analyzed. Mites were removed when present and the prevalence and intensity of parasites was calculated. The aim of this study was to search and report new Odonata hosts species that are parasitized by water mite larvae and also to evaluate the prevalence and intensity rates; the differences in mite occurrence and frequency between males and females, and between thorax and abdomen of the dragonflies and damselflies in the southern Pampa biome located in Rio Grande do Sul. A total of 162 larval mites were found associated to two Odonata families: Coenagrionidae (Acanthagrion lancea Selys, 1876, Ischnura capreolus Hagen, 1861 and Ischnura fluviatilis Selys, 1876) and Libelullidae (Micrathyria ocellata Martin, 1897 and Perithemis mooma Kirby, 1889). All mites were identified as Arrenurus (Arrenurus) sp. (Arrenuridae) and showed high numbers when attached to I. capreolus (55.5%), I. fluviatilis (33.3%), followed by low numbers on M. ocellata (6.1%), A. lancea (3.7%), and P. mooma (1.2%). Mites were found on males and females of I. capreolus and I. fluviatilis, females of A. lancea and P. mooma and in M. ocellata only in males. As the parasitized Odonata species are generalist and abundant in all water body types, traits associated with mating and oviposition or larval behavior are believed to explain the frequency of parasitism in these species.

The South of Brazil is the largest producer of grapes, however this production is affected by climate and herbivores such as phytophagous mites. The aim of this work was to associate the mite fauna with the grape cultivars Chardonnay, BRS Lorena and hybrid cultivars rootstock Paulsen 1103, in trellising and espalier systems, in the municipalities of Bento Gonçalves and Garibaldi, Rio Grande do Sul State, Brazil. The cultivars were: Chardonnay trellis (Cl) Chardonnay espalier (Ce), BRS Lorena trellis (Ll), BRS Lorena espalier (Le) and the hybrid cultivars Paulsen rootstock 1103 (Pa). Monthly samplings were carried out from November 2016 to April 2017. Twenty plants per area were randomly sampled, from each plant three apical leaves were collected, apical, median and basal branches (60 leaves / area). In total, 6,865 mites belonging to seven families, 13 genera and 22 species were collected. The most abundant phytophagous belong to Tarsonemidae and Tenuipalpidae, the predators to Phytoseiidae and the generalists to Tydeidae and Iolinidae. The cultivars Lorena Ll was the greatest similarity (82.39%) among species mites, followed by Paulsen Pa (72.54%), Lorena Le (70.67%), Chardonnay Cl (31.79%) and Chardonnay Ce (31.48%). The highest dissimilarity among the cultivars occurred between Chardonnay Ce and Lorena Le (66.49%), followed by Chardonnay Ce, Chardonnay Cl (66.44%), Chardonnay Ce and Lorena Ll (61.49 %). Thus, there is homogeneity between the sampled cultivars and the conduction systems and the apical third of the leaves and the sampling period are important in determining the composition of the species.

In this paper, we presented additional information to the description of Cheletomimus (Hemicheyletia) wellsi (Baker, 1949) (Acari: Cheyletidae) collected on Vitis vinifera L. (Vitaceae), Ruellia angustiflora (Ness) Lindau ex Rambo (Acanthaceae) from Dois Lajeados, Marques de Souza and Pantano Grande municipalities in Rio Grande do Sul state, and on Malus domestica Borkh (Rosaceae) in Campo do Tenente municipality, Paraná state, Brazil. The specimens examined presented intraspecific variations from those described previously. These variations will be discussed herein. A key to the known Brazilian species of the genus is provided.

Viticulture is one of the main economic activities in Rio Grande do Sul (RS), Brazil, with emphasis on the American grape varieties, Vitis labrusca L. (Vitaceae), used in producing juices and wines. The present work aimed to identify the mite species associated with American grapevines (V. labrusca), their possible natural enemies, and their population fluctuations. The selected varieties were: Bordô (Bd) and Couderc (Cc and Cd) in Dois Lajeados (RS), Bordô (Bi) in Imigrante (RS) and Bordô (Bp), in Putinga (RS). The study was conducted monthly between March 2017 and March 2018, evaluating 20 randomly selected plants from each municipality. We found 5,452 mites belonging to 13 families, distributed across 29 genera and 42 species, or belonging to the suborder Oribatida. Higher mite richness was observed on Cc (12 species) and higher abundance on Cd (2,812 specimens), Cc (868) and Bi (799). Among the predatory mite families, Stigmaeidae had the highest abundance (896 specimens), followed by Phytoseiidae (746). The most abundant species observed were Euseius mesembrinus (Dean), Agistemus riograndensis Johann & Ferla, Tydeus californicus (Banks), Polyphagotars-onemus latus (Banks) and Tarsonemus sp. This is the first study in southern Brazil that evaluates and reports the mite fauna and its ecology on American grape varieties, with high abundance and frequency of predatory mites. This work is important to assist in implementing management techniques that promote the maintenance of predatory mite species in these vineyards.

A new species of Stigmaeidae (Acari: Trombidiformes), namely Eustigmaeus crassifolius Bizarro and Johann n. sp., is described and illustrated based on females collected on Byrsonima crassifolia (L.) Kunth (Malpighiaceae) in Belém city (1°26'09.2'' S 48°26'28.6'' W), Pará state, Brazil. A dichotomous key of Brazilian species of Eustigmaeus genus is provided.

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