Tydeid mites have a cosmopolitan distribution and are associated with diverse substrates such as soil, plants, stored products, and animals like vertebrates and insects. Here we report two new species of tydeid mites living inside stingless bee colonies in Brazil. Lorryia meliponarum n. sp. and Melissotydeus bipunctata n. sp. are described and illustrated, and in addition a key to the species of Melissotydeus is presented.

The aim of this work was to know the population fluctuation of the mites in apple (Malus domestica Borkh: Rosaceae) orchards with different crop management strategies, with emphasis on Aculus schlechtendali Nalepa (Eriophyidae) and Panonychus ulmi (Koch) (Tetranychidae) and their natural enemies. The studies were carried out in 2020-21, in three organic orchards (Eva, Fuji and Gala), from Antônio Prado, two conventional (Fuji and Gala), from Muitos Capões, RS, Brazil, and two of regenerative agriculture (Fuji and Gala), in São Joaquim, SC, Brazil. Forty plants/orchard were sampled, from which three leaves/plant from the apical, median and basal offshoot were detached. The material was screened and identified in the laboratory. A total of 7.193 specimens, belonging to 14 families, 29 genera, and 40 species, were collected. The most common phytophagous mites were A. schlechtendali (46.2%), P. ulmi (16.9%) and Polyphagotarsonemus latus Banks (Tarsonemidae) (10.9%). Panonychus ulmi was observed in all orchards, being abundant in conventional and regenerative orchards. The most common predatory mites were Neoseiulus californicus (McGregor) (Phytoseiidae), Agistemus riograndensis Johann and Ferla (Stigmaeidae) and Agistemus brasiliensis Matioli, Ueckermann and Oliveira (Stigmaeidae). Among predators, greater diversity was observed in organic orchards, while in conventional and regenerative orchards N. californicus was the most common. Greater acarine abundance was observed when there was an increase in temperatures, and the predatory mites increased their populations in response to the presence of phytophagous mites. The results suggest that the mite populations were influenced by the cultivar and mainly by the management used.

The Brazilian Pampa is predominantly composed of native grasslands with riparian forest formations. It preserves a rich biodiversity and provides vast biological resources for economic uses. The objectives of this study were to compare the mite fauna composition on plants in three environments i.e. grassland, grazing exclusions, and riparian forest; to relate mites with microclimatic factors, and to evaluate interactions between mites and vascular plants. Data analysis was based mainly on the relationship between mite and plant species. A total of 117 mite species were collected, most of which were phytophagous (57%). Our studies revealed that mite communities from riparian forest differ from grazing exclusions and grasslands. Grassland and grazing exclusions were dominated by two species i.e. Brevipalpus sp2 and Tydeus californicus (Banks). In the riparian forest, the most abundant species was Lorryia formosa (Cooreman). In conclusion, mites represent environmental indicators of microclimatic factors and landscape. All the sampling sites had high interaction between mites and plants.

A new species of Stigmaeidae (Acari: Trombidiformes), namely Stigmaeus pampaensis Da-Costa & Johann n. sp., is described and illustrated based on the specimens collected from litter in the municipality of São Francisco de Assis, Rio Grande do Sul state, Brazil. A key to the Brazilian species is provided.

Grapevines (Vitis vinifera) require care from budding to harvest and are susceptible to both biotic and abiotic factors, such as infestations by insects, mites, fungi, and pathogenic viruses. This study aimed to evaluate the changes in i) the concentration of chlorophyll a (Chl a), b (Chl b), and total chlorophyll (Chl t), ii) plasma membrane integrity, and iii) stomatal density caused by Tetranychus urticae in different initial population densities maintained on Chardonnay grapevine leaves. The experiment was conducted with four treatments: control (0 mites/leaf), T25 (25 mites/leaf), T50 (50 mites/leaf), and T100 (100 mites/leaf), over eight days. Statistical analysis of the data indicated that the mite density on the leaves did not significantly influence stomatal density or the average levels of Chl a and Chl t. No difference was observed in the number of stomata between treatments. However, a significant difference was observed in the average amount of Chl b at T25, and a continued increase in leaf perforations was noted as a function of mite density. The results suggest that, although the infestation did not alter all the assessed parameters, the presence of T. urticae impacts Chl b and leaf integrity, thereby affecting the health and productivity of the vine. These findings underscore the importance of monitoring and managing mite populations in vineyards to minimize damage.