The genus Perissopalla Brennan and White, 1960 (Trombidiformes: Trombiculidae) in Brazil: Redescriptions, new localities, and host records with the first molecular data for the genus.

The genus Perissopalla Brennan and White (Trombidiformes: Trombiculidae) is currently represented by ten species with three from Brazil: Perissopalla barticonycteris Brennan, Perissopalla ipeani Brennan, and Perissopalla tanycera Brennan. In the present study, these three species are redescribed and illustrated based on the types and additional non-type specimens. New host and locality records for P. ipeani and P. tanycera are included. Additionally, a partial sequence for the 18S rRNA gene for P. ipeani was provided.

Influence of temperature on the population size of Aceria litchii (Acari: Eriophyidae) and the development of its galls.

The lychee erinose mite, Aceria litchii (Keifer), is a tiny eriophyid mite known to induce the formation of open galls (erinea) on lychee plants, Litchi chinensis Sonn. In lychee infested by A. litchii, four stages of erineum are observed, based on erineum color: hyaline, white, amber and dark brown. The cause of the color change in erinea is unknown, but it might be linked to the extent of A. litchii infestation. Artificially infested lychee seedlings were used to determine the developmental time, trichome density, and mite population size in each of the four erineum stages. The effect of temperature (15, 25, and 35 °C) on A. litchii population size and erineum developmental time was also investigated. Overall, each erineum stage lasted approximately 50 days and the population size of A. litchii increased gradually through the hyaline, white and amber stages, and a strong decline was observed in dark brown erinea. Visual comparisons of the low-temperature scanning electron microscope (LT-SEM) images revealed that the trichome density was lower in the hyaline stage than in the other stages. Temperature influenced mite population size and amber erinea developmental time. Mite population was lower at 35 °C than at 15 and 25 °C, suggesting that high temperatures promote detrimental effects on A. litchii. Amber erinea developed slower at 15 °C than at 25 and 35 °C. Possible effects of the temperature on A. litchii population in lychee plants are discussed.

A New Species of Ultratenuipalpus (Acari: Tenuipalpidae) from Brazil and Re-Description of Ultratenuipalpus meekeri (De Leon), the Type Species of the Genus, with DNA Barcodes.

Species of the genus Ultratenuipalpus bear a broad subquadrate propodosoma with many large, flattened, lanceolate to ovate dorsal setae. They also bear some plesiomorphic character states, such as the presence of three pairs of ventral ps setae. Here, we describe Ultratenuipalpus parameekeri Castro, Ochoa & Feres sp. nov. based on adult females, males, and immatures, collected on ferns from Brazil. We also re-describe Ultratenuipalpus meekeri (De Leon), the type species of the genus, based on types and newly collected material from Mexico, and include additional novel data (e.g., dorsal and ventral ornamentation, leg chaetotaxy, and setal measurements) in a standardized form. We include highly detailed images obtained using LT-SEM, accompanied by DNA barcodes, for both species. The ontogenetic additions of leg chaetotaxy are presented and discussed.

Where Eriophyoidea (Acariformes) Belong in the Tree of Life.

Over the past century and a half, the taxonomic placement of Eriophyoidea has been in flux. For much of this period, this group has been treated as a subtaxon within Trombidiformes. However, the vast majority of recent phylogenetic analyses, including almost all phylogenomic analyses, place this group outside Trombidiformes. The few studies that still place Eriophyoidea within Trombidiformes are likely to be biased by incomplete taxon/gene sampling, long branch attraction, the omission of RNA secondary structure in sequence alignment, and the inclusion of hypervariable expansion-contraction rRNA regions. Based on the agreement among a number of independent analyses that use a range of different datasets (morphology; multiple genes; mitochondrial/whole genomes), Eriophyoidea are almost certain to be closely related to Nematalycidae, a family of vermiform mites within Endeostigmata, a basal acariform grade. Much of the morphological evidence in support of this relationship was apparent after the discovery of Nematalycidae in the middle of the 20th century. However, this evidence has largely been disregarded until very recently, perhaps because of overconfidence in the placement of Eriophyoidea within Trombidiformes. Here, we briefly review and identify a number of biases, both molecular- and morphology-based, that can lead to erroneous reconstructions of the position of Eriophyoidea in the tree of life.

Beyond the Limits of Light: An Application of Super-Resolution Confocal Microscopy (sCLSM) to Investigate Eocene Amber Microfossils.

Amber is known as one of the best sources of fossil organisms preserved with exceptional fidelity. Historically, different methods of imaging have been applied to amber, including optical microscopy and microtomography. These methods are sufficient to resolve millimeter-scaled fossils. However, microfossils, such as microarthropods, require another resolution. Here, we describe a non-destructive method of super resolution confocal microscopy (sCLSM) to study amber-preserved microfossils, using a novel astigmatid mite species (genus Histiogaster, Acaridae) from Eocene Rovno amber as a model. We show that the resolution obtained with sCLSM is comparable to that of scanning electron microscopy (SEM) routinely used to study modern mites. We compare sCLSM imaging to other methods that are used to study amber inclusions and emphasize its advantages in examination of unique fossil specimens. Furthermore, we show that the deterioration of amber, which manifests in its darkening, positively correlates with its increased fluorescence. Our results demonstrate a great potential of the sCLSM method for imaging of the tiniest organisms preserved in amber.

Bacterial pathogens' screening in Brazilian chigger mites (Trombidiformes: Trombiculidae), with the first report of 'Candidatus Rickettsia colombianensi'-like in avian-associated chiggers.

Chiggers are larval ectoparasites of the Trombiculidae that can transmit pathogens to their hosts. In this study, chiggers collected from birds in Brazil were morphologically identified as Blankaartia sinnamaryi, Eutrombicula batatas, Eutrombicula daemoni, Eutrombicula goeldii, Eutrombicula tinami, and Parasecia gilbertoi. For these specimens, a beginning attempt at molecular identification were also provided, as well as, were genetically screened to detect bacterial pathogens. The species B. sinnamaryi and E. tinami were positive for Rickettsia felis-like and 'Candidatus Rickettsia colombianensi'-like, respectively. For the other agents (Anaplasmataceae, Borrelia spp. and Orientia tsutsugamushi), the tests were negative. This is the first report of 'Ca. R. colombianensi'-like and the second record of R. felis-like in chigger collected on birds from Brazil.

Revision of Neotrichobia Tuttle & Baker (Acari, Tetranychidae) with ontogenetic development and redescription of N. arizonensis.

The genus Neotrichobia Tuttle & Baker is redescribed with a revised diagnosis. The type species Neotrichobia arizonensis Tuttle & Baker, 1968 is redescribed based on larvae, protonymphs, deutonymphs and adults including the paratype male and deutonymph.

Review on the Genus Stylophoronychus (Acari: Tetranychidae), with Description of a New Species.

Only two species of the genus Stylophoronychus, S. baghensis (Prasad, 1975) and S. guangzhouensis (Ma and Yuan, 1980), have been recorded in China. Herein we describe a new species Stylophoronychus wangaePan, Jin & Yi sp. nov. based on characteristics of the deutonymphs and adults. The synonym of S. guangzhouensis (Ma and Yuan, 1980) and S. lalli (Prasad, 1975) with S. vannus (Rimando, 1968) is proposed. A redescription of S. vannus (Rimando, 1968) based on the adults of both sexes, deutonymphs and a protonymph is given. The ontogenetic changes of leg chaetotaxy in two species are given and discussed. The updated key to the species of Stylophoronychus of the world is provided.

Sleeping with the enemy: case reports of Ornithonyssus bursa (Berlese, 1888) (Mesostigmata: Macronyssidae) causing human dermatitis in Brazil.

Ornithonyssus bursa, known as the "tropical fowl mite," is a hematophagous mite of domestic and wild birds, which occasionally bites humans. Accidental bites on humans occur mainly when abandoned bird nests are close to homes or when people are handling parasitized birds. In the present study, we describe five case reports of bites on humans and new records of localities for this species. Based on the material examined, we provide morphological and molecular characterizations for this species herein.

Identification of the fibroin of Stigmaeopsis nanjingensis by a nanocarrier-based transdermal dsRNA delivery system.

Stigmaeopsis nanjingensis (Ma and Yuan) (Acari: Tetranychidae) is an important pest of bamboo-feeding behavior and silk production by the female adult mites is seriously harmful to bamboo leaves. Due to its small size, silking and cocooning, its management is difficult. This study discusses a fast and easy method for management of the pest by disturbing the spinning behavior. Stigmaeopsis nanjingensis is host specific and feeds only on bamboo leaves. Leaf margins of bamboo are highly hydrophobic, which makes dsRNA difficult to immerse. Hence, it is a challenge to apply the commonly used feeding method to inhibit gene expression in mites. In this study, we deliver dsRNA to interfere with the expression of fibroin by body wall permeation with a nanocarrier-based delivery system. The dsRNA/nanocarrier formulation droplets could enter the body cavity within 2 min after falling on the mite. The fibroin silencing efficiency was 75.4%, and the results of electron microscopy showed that dsRNA/nanocarrier damage the morphological structure of the silk thread. This study demonstrated the effectiveness of a nanocarrier-based percutaneous dsRNA delivery system in S. nanjingensis and its effect on the fibroin gene that influences the spinning behavior of S. nanjingensis. These findings may provide a new delivery system for RNAi-based control of spider mites that utilize protective webbing in the field.

Report of Tuckerella pavoniformis (Acari: Tuckerellidae) on Mamey, Mammea americana (Calophyllaceae), in Northwestern Peru.

The family Tuckerellidae, or peacock mites, is a monogeneric group comprising approximately 32 species, which are usually collected from the fruits or woody parts of their host plants. Fruits and branchlets of mamey, Mammea americana L. (Calophyllaceae) trees in north-western Peru were sampled for peacock mites throughout spring and summer for two consecutive years. This is the first record of Tuckerella pavoniformis (Ewing) (Acari: Tuckerellidae) feeding on mamey. Aggregations of mites were much higher and more common on the fruit epicarps than on branchlets. Recommendations for the development of an Integrated Pest Management strategy for this peacock mite are included.

Population Dynamics of Eriophyid Mites and Evaluation of Different Management Practices on Timothy Grass.

Several species of eriophyid mites are important economic pests of timothy grass in the Mid-Atlantic United States. Feeding causes stunting, curling, and brown discoloration of leaves, and yield losses ranging up to 50%. Carbaryl is the only approved chemical control for these mites. We investigated the population dynamics of field infestations, host plant resistance, and several cultural control measures to develop a more sustainable management strategy. Seasonal phenology and overall abundance differed among timothy fields and between years, with mean peak densities ranging up to 731 eggs and 1,163 mites per 2.5 cm of leaf blade. Population differences were related to the age of the field, the prevailing temperatures, and snow cover during the fall and winter months. All varieties of timothy tested were susceptible, whereas several other forage grasses were significantly resistant to eriophyid mites as possible alternatives for replacing timothy. Fall harvesting reduced the buildup of mites during the winter but populations eventually rebounded and still reached economic densities by April. Burn-down herbicide, prescribed burning, and urea-based fertilizer treatments prior to green-up in the early spring had variable effects and may help to prevent economic losses; however, several concerns about the benefit/costs and practicality of these practices are discussed.

Temporal Incidence of Eriophyid Mites on Rose Rosette Disease-Symptomatic and -Asymptomatic Roses in Central Georgia, USA.

Phyllocoptes fructiphilus Keifer (Acari: Eriophyidae) is the vector of rose rosette virus (RRV), which causes rose rosette disease (RRD) in North America. The RRD symptoms, such as witches' broom, flower, and leaf deformation, disrupt the aesthetic appearance of plants and cause plant mortality. Because there is no cure for RRV, it is critical to manage the vector and reduce the spread of the virus. The information on the phenology of P. fructiphilus on rose plants is essential to develop management strategies and reduce its spread. Thus, the objectives of the study were to determine 1) the phenology of eriophyid mites (including P. fructiphilus) in central Georgia due to its widespread occurrence in the state and 2) the incidence of eriophyid mites on closed and opened flower buds and other plant parts. In central Georgia, eriophyid mites, including P. fructiphilus were active on both symptomatic and asymptomatic plants from April to December. The mite densities were greater during July and August than during the remaining months on asymptomatic plants. The mites were more abundant on the RRD-symptomatic than on the asymptomatic plants. Similar numbers of eriophyid mites were observed on closed and opened flower buds. Eriophyid mite densities were greater on sepals and leaf bases than on other plant parts.

First Record of Cenopalpus wainsteini [Trombidiformes: Tetranychoidea: Tenuipalpidae] in the Americas and a Description of the Symptoms It Causes on Pines in Peru.

Cenopalpus wainsteini (Livshitz and Mitrofanov, Proceedings Nikitsky Botanic Garden 39:1-72, 1967), a mite species in the family Tenuipalpidae, was discovered on Pinus sylvestris Thumb. in Lima, Peru, and represents the first record of this species in the Americas. Previously, only Cenopalpus pulcher (Canestrini and Fanzago Acari Academia Cientifico Veneto 5:130-142, 1876) and C. officinalis (Papaioannou-Souliotis, Annals Institut Phytopathology Benaki 15:11-27, 1986) have been reported from the Nearctic and Neotropic regions. The current paper describes and illustrates the morphological characters of female, deutonymph, protonymph and includes the first description of the larval stage of the species. Species of C. wainsteini collected in Peru were compared with specimens collected in Italy, as well as with the original description by Livschitz and Mitrofanov of specimens from Ukraine and the re-description of the species by Arabuli and Kvavadze Int J Acarology 39(7): 538-541 (2013) based on specimens collected in Georgia. Furthermore, notes on Cenopalpus lineola (Canestrini and Fanzago 1876) are included since it is frequently associated with C. wainsteini. Severe damage symptoms caused by this flat mite on its host plants were observed and are discussed herein.

Sleeping with the enemy: case reports of Ornithonyssus bursa (Berlese, 1888) (Mesostigmata: Macronyssidae) causing human dermatitis in Brazil

Ornithonyssus bursa, known as the “tropical fowl mite,” is a hematophagous mite of domestic and wild birds, which occasionally bites humans. Accidental bites on humans occur mainly when abandoned bird nests are close to homes or when people are handling parasitized birds. In the present study, we describe five case reports of bites on humans and new records of localities for this species. Based on the material examined, we provide morphological and molecular characterizations for this species herein.

Charletonia rocciai treat and Flechtmann, 1979 (Trombidiformes: Erythraeidae): larval redescription and new records for Brazil

The family Erythraeidae has 60 genera worldwide, of which Charletonia Oudemans has 86 described species, only two of which are recorded in Brazil. Here, we redescribe one of these species based on the holotype, Charletonia rocciai Treat and Flechtmann, and newly collected material. The material represents new records from four different localities in São Paulo State and one in Santa Catarina State. In addition, we provide SEM images of the morphological structures to improve the diagnosis and redescription, an updated distribution map, including biological data, and new host-associations of C. rocciai with the following orders of insects, Coleoptera and Thysanoptera, and with an order of Arachnida – Araneae.

Size, shape, and direction matters: Matching secondary genital structures in male and female mites using multiple microscopy techniques and 3D modeling.

Studies of female genital structures have generally lagged behind comparable studies of male genitalia, in part because of an assumption of a lower level of variability, but also because internal genitalia are much more difficult to study. Using multiple microscopy techniques, including video stereomicroscopy, fluorescence microscopy, low-temperature scanning electron microscopy (LT-SEM), and confocal laser scanning microscopy (CLSM) we examined whether the complex sperm transfer structures in males of Megalolaelaps colossus (Acari: Mesostigmata) are matched by similarly complex internal structures in the female. While both LT-SEM and CLSM are well suited for obtaining high-quality surface images, CLSM also proved to be a valuable technique for observing internal anatomical structures. The long and coiled sperm transfer organ on the chelicera of the males (spermatodactyl) largely matches an equally complex, but internal, spiral structure in the females in shape, size, and direction. This result strongly suggests some form of genital coevolution. A hypothesis of sexual conflict appears to provide the best fit for all available data (morphology and life history).

Dorsal setae in Raoiella (Acari: Tenuipalpidae): Their functional morphology and implication in fluid secretion.

The setae of mites are not regarded as secretory structures, yet in the flat mite genus Raoiella, each developmental stage presents droplets of fluid associated with the tips of their dorsal setae. To understand the origin of this fluid, the ultrastructure of the dorsal setae is investigated in females of Raoiella bauchani Beard & Ochoa and the invasive pest species Raoiella indica Hirst using scanning and transmission electron microscopy techniques. The dorsal setae are barbed along their entire length and have either a broadened plumose or a flat spatulate tip. Ultrastructurally, they present the typical features of mechanoreceptors, but have a "hollow" axis represented by a protoplasmatic core containing dendritic branches. This combination of ultrastructural characters indicates that the setae might be multimodal receptors: acting as both mechanoreceptors and contact chemoreceptors. The epidermal cells that underlie the setal sockets are columnar and have an ultrastructure that suggests they have a glandular function. Moreover, these cells present regular microvilli apically and form extracellular cuticular canals, containing epicuticular filaments, that are connected with the microvilli proximally and which open via pores onto the surface of the setal base distally. This arrangement indicates that the secretion from the microvilli passes into the canals and is then conducted to pores at the base of the seta, where it then accumulates and moves up the setal shaft, along the longitudinal grooves of the barbs. Based on similar arrangements in some insect taxa, the organization of the structures here observed in Raoiella suggests the passage of a non-polar, water insoluble, lipoid fluid through the cuticle, the function of which is still obscure.

A Revision of Parasecia (Trombidiformes: Trombiculidae) With a Description of a New Species, a New Genus and a Key to Species.

Chiggers of the genus Parasecia Loomis parasitize birds, mammals, and reptiles in the Nearctic and Neotropical regions. In the present review, we examined 18 species previously included in the genus, 15 of them being retained in the genus Parasecia, one genus is created, Nahuacarus bulbocalcarn. gen. (Trombidiformes: Trombiculidae), and new combinations are proposed for two species: Lorillatum lasiurusn. comb. and Lorillatum orphanan. comb. (Trombidiformes: Trombiculidae). In addition, Parasecia kansasensis (Loomis) (Trombidiformes: Trombiculidae) is synonymized with Parasecia gurneyi (Ewing) (Trombidiformes: Trombiculidae), Parasecia gilbetoin. sp. (Trombidiformes: Trombiculidae) is described and new locality and host records are added for Parasecia chara (Wharton), Parasecia longicalcar (Brennan and Jones), Parasecia manueli (Brennan and Jones), and Parasecia thalurania (Brennan) (Trombidiformes: Trombiculidae).

Italian acarine species intercepted in the United States

In the last century, biological invasions have increased greatly due to the intensification in international trade and world climate change, thus representing one of the most relevant issues for agricultural productivity and biodiversity. The Animal and Plant Health Inspection Service of the United States, from 2019 to 2021, intercepted different species from Italy belonging to the Orders Ixodida, Sarcoptiformes and Trombidiformes. The study reported four new records and several new host plant associations. In this framework, the inspection system not only plays a relevant role in the plant protection, human and animal health, but also contributes to the knowledge of the Acari fauna from exporting countries.