Gamasellodes garybauchani sp. nov. Rueda-Ramírez & Santos is described based on specimens collected at the Beltsville Agricultural Research Center (BARC) (Maryland, USA). Twenty-one specimens were used for the description, of which five were subjected to low temperature scanning electron microscopy (LTSEM), followed by DNA extraction for genetic analysis and subsequent slide mounting. The remaining 16 specimens were subjected to only DNA extraction for genetic analysis and subsequent slide mounting. Morphological characters of the new species observed both in the images obtained in LTSEM and in the observation of the mounted specimens are detailed. Molecular information available on the Barcode of Life Datasysetm (BOLD) is presented. An update to the recent key to the Gamasellodes species is provided.

Current and future legislation requiring the reduction of pesticides use, coupled with global initiatives for the promotion of soil health and conservation of soil biodiversity are creating opportunities for studies aimed at highlighting ecosystem services provided by functioning soil food webs in agricultural systems, including soil predatory mites. However, the key personnel for performing such studies are expert taxonomists, who are already spread very thin. To meet this demand, we propose an integrative approach where scientists (without expertise in taxonomy) play a significant role in supporting expert taxonomists. Soil samples were collected at the USDA ARS Farming Systems Project (FSP) at the Beltsville Agricultural Research Center, either incubated or not, followed by extraction of mites and nematodes. Improved modified Berlese funnels and an extraction protocol were utilized to improve sequencing success. Incubation dramatically enhanced the number of extracted individuals per sample whilst the daily freezing of extracted mites substantially improved the sequencing success rate compared to previous studies. Taken together, this led to the addition of records for eight Mesostigmata and ten Oribatida BINs to BOLD (Barcode of Life Datasystem). Fifteen species of Mesostigmata species were found, with three dominant species, Cycetogamasus diviortus (Athias-Henriot, 1967) (Parasitidae), Lasioseius youcefi Athias-Henriot 1959 (Blattisociidae) and a new species of Gamasellodes (Ascidae). LTSEM imaging followed by molecular identification contributed further details to the published descriptions of C. diviortus and L. youcefi. In line with our general aim, collecting, extracting, identification to morpho-species, sample preparation for DNA barcoding and uploading relevant information to BOLD was performed by trained personnel, but without taxonomic expertise. Whereas our skilled taxonomists focused on the morphological identifications using light microscopy, expanding on existing descriptions using LTSEM images and in a subsequent manuscript the description of a new species. We believe this division of tasks and labor will set the stage for further collaborative integrated studies between ecologists, biocontrol specialists and expert taxonomists for the identification, evaluation, and description of known and novel soil acarine biological control agents (BCAs).

Deutonymphs of two new genera in the family Winterschmidtiidae, subfamily Winterschmidtiinae, are described from the Eastern United States and compared with existing taxa. Bostrichiella delfinadoae gen. nov., sp. nov. is described from Xylobiops basilaris (Say, 1824) from Connecticut, Tennessee, Louisiana and Florida. Xylacarus bauchani gen. nov., sp. nov. is described from Amphicerus bicaudatus (Say, 1824) and A. cornutus (Pallas, 1772), from New Jersey, New York, Michigan and Florida. A few specimens of each species were collected from other bostrichid species. The two new genera are sister-taxa and more closely related to Winterschmidtia than to Parawinterschmidtia. A table of all species included in the Winterschmidtiinae is presented.

Most species of the mite genus Winterschmidtia Oudemans, 1923 are associated with bark beetles. These mites are predacious on eggs of their coleopteran hosts and may be potential biocontrol agents for pest species of bark beetles. Here we describe three new species of Winterschmidtia from Peru based on phoretic deutonymphs: W. parallela sp. nov. (from Loganius flavicornis), W. alekhini sp. nov. (from Phloeotribus biguttatus) and W. reducta sp. nov. (from Phloeotribus pilula). The name Calvolia fusiformis Zachvatkin, 1941 was recombined as Winterschmidtia fusiformis (Zachvatkin, 1941) com. nov. An illustrated key to species of the genus Winterschmidtia (phoretic deutonymphs) of the world is provided.

The single known specimen of the monotypic genus Caenonychus Oudemans, 1902 was examined. No distinguishing characters could be found to justify the retention of Speleorchestes Trägårdh, 1909 as a separate genus from Caenonychus. Grandjean (1939) suspected these genera were synonymous but retained Speleorchestes as valid because of a difference between the two genera in opisthosomal shape. An artifactual explanation for the difference in opisthosomal shape is herein accepted based on the effects of applying different pressures to the coverslip over the same specimen. Therefore, Speleorchestes is treated as a junior synonym of Caenonychus.

Spider mites from Florida identified as Tetranychus gloveri Banks yielded COI and ITS1/ITS2 sequences that were either highly similar or identical to GenBank sequences of Tetranychus okinawanus Ehara from Japan. In the description of T. okinawanus, only a single morphological character, the length of the solenidion on tarsus III, was used to separate T. okinawanus from T. gloveri. Using types of both species, this character was reassessed and is shown to provide no basis for the treatment of T. okinawanus as a distinct species. Therefore, we assert that Tetranychus okinawanus Ehara is a junior synonym of Tetranychus gloveri Banks. We also provide a diagnosis and supplementary description of T. gloveri based on specimens from available geographic regions (USA: Louisiana, Florida; Japan) and designated a female lectotype.

A new tribe, Obuloidini tr. nov. Beard, Ueckermann & Seeman, is proposed to include the genera Krugeria Meyer, Obuloides Baker & Tuttle and two new genera, Bauchania gen. nov. Beard & Seeman and Krobuloides gen. nov. Ueckermann. The genus Krugeria is revised, with the redescription of the type species Kru. ramosa Meyer (based on type material) and the addition of four new species, Kru. neseri sp. nov. Beard & Seeman, Kru. tshipise sp. nov. Beard & Seeman, and Kru. esseleeae Ueckermann from South Africa, and Kru. ueckermanni Beard & Seeman from Australia (new generic record). A new genus from South Africa, Krobuloides gen. nov. Ueckermann, is described based on three new species, Kro. aydeni sp. nov. Ueckermann, Kro. eduani sp. nov. Ueckermann and Kro. waldoi sp. nov. Ueckermann. The genus Obuloides is revised with redescriptions of the following species, all based on type material: the type species O. rajamohani Baker & Tuttle from India; O. rimando Corpuz-Raros from The Philippines; and O. crinitus Maake & Ueckermann, O. flavae Ueckermann, Theron & Tiedt, O. inquilinus Ueckermann et al., O. namibiensis Ueckermann et al., O. occidentalis Ueckermann et al., and O. ruginosus Ueckermann et al. from South Africa. A new genus, Bauchania gen. nov. Beard & Seeman, is described from Australia, based on two new species, B. dampiera sp. nov. Beard & Seeman and B. goodenia sp. nov. Beard & Seeman. A discussion of the character states shared by these four genera is presented, with a key to separate them.

The flat mite genus Raoiella Hirst (Tenuipalpidae) has attracted considerable research interest due to the rapid spread of Raoiella indica Hirst which feeds most commonly on species of palms (Arecaceae). Raoiella are frequently observed with their stylets inserted into the leaf stomatal openings, suggesting they feed on this site. Herein, we use transmission electron microscopy (TEM), scanning electron microscopy (SEM), low temperature scanning electron microscopy (LTSEM) and light microscopy (LM) to describe the mouthpart organization and the feeding behavior found in R. indica and R. bauchani Beard & Ochoa. The feeding mechanism is also discussed based on their distinctive morphological aspects. The structure of the gnathosoma of Raoiella generally agrees with the organization previously observed in Brevipalpus and Cenopalpus. As in other tetranychoid mites, there is no anatomical connection between the inter-stylet tube and the food channel, corroborating the theory that the stylets are used to pierce plant tissue (and assumedly inject saliva) but play no role in sucking up fluid from damaged host cells. As in Brevipalpus, the adoral setae are mechanoreceptors that may help guide the mite to the site for feeding. The ultrastructure of supracoxal setae e remains enigmatic. We also present observations of possible epidermal feeding on Phoenix roebelenii O'Brien (Arecaceae) for R. indica. Raoiella indica were shown to penetrate both the guard cells of the stomata and the epidermis of P. roebelenii, suggesting that feeding via the epidermis could be possible on this host plant.

A new species of flat mite (Acari: Tenuipalpidae), Tenuipalpus bauchani sp. nov., collected on Trichilia casaretti C. de Candolle and T. elegans A. Juss (Meliaceae), is described from the State of São Paulo, Brazil. A key to the Brazilian species of Tenuipalpus based on females is provided.

The family Tarsonemidae (Acari: Prostigmata) exhibits a high diversity of feeding habits and morphological structures, which allow them to be successful in many habitats. In Costa Rica, the Mesoamerican forest is a biome that includes all tropical and subtropical natural plant formations with high biodiversity. In Brazil, Theobroma cacao L. (Malvaceae) is cultivated under the canopies of larger trees, in a shaded plantation system called cabruca. Two new Metatarsonemus species are described from Brazilian cabruca agroforest. New records for the genus from Mesoamerica, Atlantic Forest and cabruca agroforest are presented. A key to the species of Metatarsonemus of the world is included.