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Vineyards are a favorable culture for the habitat of phytophagous mites. These pests feed on the cellular sap of vegetables, causing damage to plants. The aim of this study was to comparatively evaluate the effects of applied biological control of Panonychus ulmi (Koch) (Tetranychidae) using Neoseiulus californicus (McGregor) (Phytoseiidae) on the physicochemical properties and bioactive compounds profile in grapes of Merlot variety, in one single property in the municipality of Bento Gonçalves, Rio Grande do Sul, Brazil. Treatments were conducted in three different areas of the vineyard: area attacked by P. ulmi (AP), area with P. ulmi controlled by N. californicus (APN), and a third area without the presence of mites (AWM). Berries in the AP treatment had lower hardness, with both test probes used (cutting line type and cylinder type). Grapes of AWM treatment had higher red coloration in parameter 'a*', both in the skin and in the pulp. Sugar content did not significantly differ between fruits from grapevines with presence of mites. In grape skins of AP treatment, total phenol, flavonoid, and anthocyanin contents were significantly higher, whereas resveratrol content was lower. Compared to fruits of grapevines without mites (AWM treatment), grapes with biological treatment (APN) had significantly higher contents of sugar, total phenols (pulp and skin), flavonoids (skin), anthocyanins (skin), and antioxidants (skin and pulp). Results suggest that biological control applied using predatory mites increases the concentration of phenolic compounds in fruits, improving the nutritional quality of the grapes. [ABSTRACT FROM AUTHOR]

Phytophagous mites can cause economic losses in many crops, including grapevines. The changes in their population levels may be associated with changes in the predator-prey relationship. Knowledge of the distribution of mites in plants is important for planning sampling strategies and facilitating control decisions. The aims of this study were to (i) evaluate the abundances of Tetranychus urticae (Tetranychidae) and Neoseiulus californicus (Phytoseiidae), and the correlations between them and environmental factors; (ii) determine their distribution on the top, middle, or base strata of the evaluated grapevines (Vitis vinifera, Chardonnay cultivar) and, additionally, report the first occurrence of damage caused by T. urticae in grapevine leaves in the state of Rio Grande do Sul, Southern Brazil. Sixteen samplings were conducted, divided between the 2018 and 2019 seasons. In each sampling, three leaves from the three strata of the plant (top, middle, and base) were collected from 20 plants, totaling 60 leaves per sampling. The predator-prey relationship and their association with environmental variables were evaluated with multivariate correlation, whereas the number of mites per plant leaf strata was compared using a generalized linear mixed model in R software. It was possible to observe the symptoms of damage caused by T. urticae attacks on grapevines in Southern Brazil, characterized by the presence of yellow spots and general yellowing of the vineyard. Our findings indicate that T. urticae and N. californicus individuals are strongly associated with each other regardless of the environmental variables, and such relationship occurs mainly on the lower strata (middle and base leaves) of grapevines. Thus, by taking into account the damage on the leaves of grapevines and the occurrence of T. urticae and N. californicus majorities on specific strata of these vineyards, we suggest that the lower strata of grapevines should be the priority targets for management strategies to control such mites. [ABSTRACT FROM AUTHOR]

BACKGROUND: Brevipalpus yothersi mite is the main vector of Citrus leprosis virus (CiLV), the causal agent of citrus leprosis disease. The acaricide spirodiclofen has been widely used to control this mite. However, failures in control using spirodiclofen have been frequently reported by citrus growers. In this study, we estimated the diagnostic concentration to monitor the resistance to spirodiclofen of B. yothersi populations collected in nine citrus groves in Brazil. We then selected the B. yothersi population that showed lowest mortality with the estimated diagnostic concentration of spirodiclofen to characterize the frequency of resistant individuals, as well as demographic and life table parameters. RESULTS: Variability was higher between populations in terms of susceptibility to spirodiclofen. The frequency of resistant eggs between populations ranged from 0.7% to 85.8%. The resistance ratio of B. yothersi to spirodiclofen was low to moderate. Survival rates of the immature stage, total adult longevity, oviposition days, and female fecundity were lower in the resistant strain. Furthermore, net reproduction rate, intrinsic rate of increase, finite rate of increase, and mean length of a generation were also lower in the R strain. CONCLUSION: Although variations in resistance to spirodiclofen were observed between populations, the resistance ratio was low to moderate. Such data can be useful in the development of resistance management strategies for B. yothersi in Brazilian citrus groves. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The objective of the present study was to determine the mite fauna associated with Myrtaceae from Cariri, a microregion with peculiar climatic conditions in the center of the Caatinga Domain in northeastern Brazil. Samples were collected in eight municipalities in Cariri region. In each municipality, five collection sites equidistant at approximately 10 km were established. The sampling was carried out in two periods, rainy season (March to April 2013) and dry season (September to October 2013). A total of 3.831 mites distributed in 14 families, 39 genera and 46 species were recorded. The Phytoseiidae was the dominant predatory mite family with 11 species. The most common phytoseiid species was Euseius concordis (Chant), followed by Euseius citrifolius Demark & Muma and Euseius alatus De Leon. Among the phytophagous mites, two families were the most abundant: Tenuipalpidae and Tetranychidae. Our results indicated that Myrtaceae in Caatinga Domains hosts a considerable diversity of potentially important predatory mites for the control of phytophagous species. [ABSTRACT FROM AUTHOR]

Mite infestations in laying hens can cause losses to producers due to stress, reduced egg production and even death of birds. A new species of mite, Allopsoroptoides galli ( A. galli ), Analgoidea: Psoroptoididae, was recently identified in commercial laying farms in Brazil, causing damage due to its highly aggressive infestation that results in a sharp drop in egg production and culling. The present study evaluated the acaricidal action of a formulation containing fluralaner (Exzolt) against A. galli. Thirty-four laying hens naturally infested with A. galli were equally divided into a fluralaner-treated group and an untreated control group. The fluralaner-treated group received Exzolt in drinking water at a dose of 0.05 mL/kg body weight (equivalent to 0.5 mg fluralaner/kg body weight), twice, 7 d apart. Both groups were followed for 70 d evaluating the level of infestation by counting mites in skin scrapings and assessment of skin lesions. The average mite count of the treated group decreased significantly, dropping from 61.6 to 3.8 mites (D+7 to D+70). The efficacy progressively increased on subsequent days, reaching 98.8% on d +56 post-treatment and 96.9% on d +70. Recovery of skin lesions was observed after administration of Exzolt, showing a marked remission in the degree of lesions (2.5 on d −14 to 0.2 on d +70). The mean number of mites in the untreated control group ranged from 79.3 to 124.1 and the lesion score from 2.6 to 2.9, thus remaining stable throughout the study. The results obtained in the present study demonstrated that Exzolt administered at a dose of 0.05 mL of product/kg body weight (equivalent to 0.5 mg of fluralaner/kg body weight), twice at a 7-d interval, in drinking water was effective in the treatment of the mite Allopsoroptoides galli in naturally infested laying hens. [ABSTRACT FROM AUTHOR]

A new species of stigmaeid mite (Acari: Stigmaeidae)Agistemus paraguariensissp. nov.is described and illustrated from the State of Rio Grande do Sul, Brazil, based on specimens collected on yerba mate (Ilex paraguariensisA. St.-Hil.) (Aquifoliaceae). A key to Brazilian species of the genus is provided. urn:lsid:zoobank.org:pub:D92FFB81-BD07-414E-A7B0-DDAA6C71CE52 [ABSTRACT FROM PUBLISHER]

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The blattisociid mite Lasioseius floridensis Berlese was found associated with the broad mite, Polyphagotarsonemus latus (Banks), on gerbera leaves in Mogi das Cruzes, State of Sao Paulo, Brazil. Blattisociid mites are not common on aerial plant parts, except under high air humidity levels. Some Lasioseius species have been mentioned as effective control agents of rice pest mites, but nothing is known about the biology of L. floridensis. The objective of this study was to evaluate whether the observed co-occurrence of L. floridensis and P. latus was just occasional or whether the latter could be important as food source for the former, assumed by laboratory evaluation of the ability of the predator to maintain itself, reproduce and develop on that prey. Biological parameters of L. floridensis were compared when exposed to P. latus and to other items as food. The study showed that mating is a pre-requisite for L. floridensis to oviposit and that oviposition rate was much higher on the soil nematode Rhabditella axei (Cobbold) (Rhabditidae) than on P. latus. Ovipositon on the acarid mite Tyrophagus putrescentiae (Schrank) was about the same as on P. latus, but it was nearly zero when the predator was fed the fungi Aspergillus flavus Link or Penicillium sp., or cattail ( Typha sp.) pollen. Survivorship was higher in the presence of pollen and lower in the presence of A. flavus or Penicillium sp. than in the absence of those types of food. Life table parameters indicated that the predator performed much better on R. axei than on P. latus. To evaluate the potential effect of L. floridensis as predator of P. latus, complementary studies are warranted to determine the frequency of migration of L. floridensis to aerial plant parts, when predation on P. latus could occur. [ABSTRACT FROM AUTHOR]

In the vineyards of the Region of the Campanha of Rio Grande do Sul, Brazil, the grape rust mite Calepitrimerus vitis (Nalepa, 1905) (Acari: Eriophyidae), has been found frequently since the 2004/2005 harvest associated with symptoms of tanning on the leaves. The fluctuation of C. vitis in 'Cabernet Sauvignon' was studied in a commercial vineyard located in Candiota, RS, during the agricultural years 2007/2008 (November-June) and 2008/2009 (October-May). The sampling was carried out on the leaves and by using traps constituted by double-faced adhesive installed in the branches of production. The populational peak in the first year occurred in March, 2008, which recorded 0.34 individuals per square centimeter of the abaxial face of the medium leaves and 29.48 individuals per traps. In the second year of the experiment, the populational peak was less intense and occurred on October, 2008, when it was detected 0.11 individuals per square centimeter of the medium leaves abaxial faces and 0.43 individuals per traps. It was detected that the beginning of the displacement of C. vitis to hibernation places occurs on summer, starting in February. The adhesive traps were more efficient in identifying the presence of C. vitis in the vineyard than the direct evaluation on leaves. A positive correlation was found between the number C. vitis on the abaxial surface of leaves and percentage of leaves infested. [ABSTRACT FROM AUTHOR]

Since its first contact with Apis mellifera, the population dynamics of the parasitic mite Varroa destructor varies from one region to another. In many regions of the world, apiculture has come to depend on the use of acaricides, because of the extensive damage caused by varroa to bee colonies. At present, the mite is considered to contribute to the recent decline of honey bee colonies in North America and Europe. Because in tropical climates worker brood rearing and varroa reproduction occurs all year round, it could be expected that here the impact of the parasite will be even more devastating. Yet, this has not been the case in tropical areas of South America. In Brazil, varroa was introduced more than 30 years ago and got established at low levels of infestation, without causing apparent damage to apiculture with Africanized honey bees (AHB). The tolerance of AHB to varroa is apparently attributable, at least in part, to resistance in the bees. The low fertility of this parasite in Africanized worker brood and the grooming and hygienic behavior of the bees are referred as important factors in keeping mite infestation low in the colonies. It has also been suggested that the type of mite influences the level of tolerance in a honey bee population. The Korea haplotype is predominant in unbalanced host-parasite systems, as exist in Europe, whereas in stable systems, as in Brazil, the Japan haplotype used to predominate. However, the patterns of varroa genetic variation have changed in Brazil. All recently sampled mites were of the Korea haplotype, regardless whether the mites had reproduced or not. The fertile mites on AHB in Brazil significantly increased from 56% in the 1980s to 86% in recent years. Nevertheless, despite the increased fertility, no increase in mite infestation rates in the colonies has been detected so far. A comprehensive literature review of varroa reproduction data, focusing on fertility and production of viable female mites, was conducted to provide insight into the Africanized bee host-parasite relationship. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine effects of total rainfall, mean temperature, predators, height of canopy, levels of nitrogen and potassium in leaves, and the density of leaf trichomes on the attack intensity of Tetranychus evansi and T. urticae (Acari: Tetranychidae) and Aculops lycopersici (Acari: Eriophyidae) in five plantations of the eggplant Solanum melongena var. ‘Natu Nobilis’ in two regions of Brazil. Higher numbers of individuals of A. lycopersici, T. evansi and T. urticae/cm2 were observed on eggplants in the Municipality of Guidoval than in Viçosa which might be explained by the fact that Guidoval showed hotter and more rainy weather. A. lycopersici was positively correlated with mean temperature (r = 0.54, P = 0.03), and T. evansi was positively correlated with total rainfall (r = 0.54; P = 0.04), while for T. urticae the correlation with total rainfall was almost significant (r = 0.47, P = 0.055). No significant effects were found (P > 0.05) of natural enemies, levels of N and K and leaf trichome density on population densities of mites. A. lycopersici showed higher density on the apical leaves while nymphs and adults of T. evansi and eggs of T. urticae had higher numbers on leaves of the apical and medium parts of eggplants than on the lower leaves. Nymphs and adults of T. urticae showed higher attack intensity on leaves from the medium and lower thirds of the plants. [ABSTRACT FROM AUTHOR]

Investigates the effects of strategic but selective acaricide treatments of cattle within herds against Boophilus microplus in the state of Rio Grande do Sul, southern Brazil. Description of a small experimental using a herd of European breed heifers that were treated with an injectable avermectin endectocide designed to act directly against the first and third generations of parasitic B. microplus per 'cattle tick year'; Results of experiments; Comparison of advantages of maintaining chemically untreated cattle ticks within a herd to their disadvantages as contaminants to classical strategic control procedures.