A new species of Scheloribates ( Acari , Oribatida , Scheloribatidae ) from Vietnam , with key to the striolatus-group

A new species of oribatid mite, Scheloribates daoensis sp. nov. is described from grass rhizosphere of meadow in the Tam Dao National Park, Northern Vietnam. It is morphologically most similar to S. striolatus Balogh, 1960, but differs by the body size, the morphology of bothridial setae, the length of circumpedal carinae and the distance between sacculi S1–S1. An identification key to known species/subspecies of striolatus-group of Scheloribates is provided.


Introduction
Scheloribates Berlese, 1908 is a largest genus of oribatid mites of the family Scheloribatidae.The genus has several subgenera, and the nominal subgenus is currently comprised of 271 species and 20 subspecies, which have a cosmopolitan distribution, collectively (Subías 2004(Subías , updated 2016)).
During taxonomic survey of oribatid mites from Northern Vietnam, we found a new species belonging to Scheloribates.Earlier, only 11 species and one subspecies of this genus were reported from this country (e.g.Ermilov et al. 2012;Ermilov & Anichkin 2013, 2014;Ermilov 2015Ermilov , 2016)).The main purpose of the paper is to describe and illustrate a new species and to present an identification key to known representatives of the striolatus-group of Scheloribates.
Methods.Specimens were mounted in lactic acid on temporary cavity slides for measurement and illustration.The body length was measured in lateral view, from the tip of the rostrum to the posterior edge Ecologica Montenegrina 10: 14-21 (2017) This journal is available online at: www.biotaxa.org/em of the ventral plate.Notogastral width refers to the maximum width behind pteromorphs in dorsal aspect.Lengths of body setae were measured in lateral aspect.All body measurements are presented in micrometers.Formulas for leg setation are given in parentheses according to the sequence trochanter-femur-genu-tibiatarsus (famulus included).Formulas for leg solenidia are given in square brackets according to the sequence genu-tibia-tarsus.Morphological terminology used in this paper follows that of F. Grandjean: see Travé & Vachon (1975) for references, Norton (1977) for leg setal nomenclature, and Norton & Behan-Pelletier (2009), for overview.Drawings were made with a camera lucida using a Leica transmission light microscope -Leica DM 2500‖.4).Body color light brown.Body surface microporose (visible under high magnification, × 1000).Lateral parts of prodorsum microgranulate.Notogaster, ventral parts of pedotecta I and lateral sides of anal plates and ano-adanal region heavily striate.
Etymology.The specific name daoensis refers to the second part of the name of the Tam Dao National Park, Northern Vietnam, where the new species was collected.

Striolatus-group in the subgenus Scheloribates
Known species of Scheloribates with entire or partially striate (forming sometimes reticulate pattern) notogaster (lines present also on ventral side in some species) can be ascribed to striolatus-group (we use this group's name for the first time).At present, this group can be emcompassed 10 species (including present new species) and one subspecies.Some species (e.g. S. schauenbergi Mahunka, 1988, S. rugosus Hammer, 1958) having stria only on the pteromorphs are not included in this newly proposed group.