Contribution to the knowledge of the oribatid mite genus Hardybodes (Acari, Oribatida, Carabodidae) with description of a new species from the Philippines

A new species of the genus Hardybodes (Oribatida, Carabodidae) is described from the nest of an unknown species of ants (Formicidae) in soil in Luzon Island, Philippines. Hardybodes minutus n. sp. differs from all species of the genus by the localization of notogastral setae (lm and h2 inserted in the same longitudinal rowdorsocentrally together with da, dm, dp, lp and h1 versus lm and h2 in dorsolateral positions and da, dm, dp, lp and h1 inserted in dorsocentral positions in the other species). Revised generic diagnosis and an identification key to the four known species of Hardybodes are presented.


Introduction
The oribatid mite genus Hardybodes (Acari, Oribatida, Carabodidae) was proposed by Balogh, 1970 with Hardybodes mirabilis Balogh, 1970 as type species. It comprises three species (Balogh 1970;Mahunka 1995), which are distributed in the Oriental and Australian regions: H. flabellatus Mahunka, 1995 andH. penicillatus Mahunka, 1995 were described from soil of tropical forest on Borneo (Mahunka 1995); H. mirabilis Balogh, 1970 from litter of small forest in New Guinea and also recorded in different plant associations in the Philippines (Corpuz-Raros 1979) and in litter of tropical forests on Borneo (Mahunka 1987). Subías (2004Subías ( , online version 2017 considers the genus Carabodella Mahunka, 1986(b) as the junior synonym of Hardybodes, including its type species Carabodella calcarata Mahunka, 1986(b) in the latter. However, we support independence of Carabodella after explanations of Fernandez et al. (2015).
In the course of taxonomic study of new materials of carabodid mites from the collection of the Museum of Natural History (University of the Philippines Los Baños), we found a new species of Hardybodes. It is the fourth representative of the genus, and the species is second only to H. mirabilis which was recorded earlier (e.g. Corpuz-Raros 1979) for the Philippine fauna.
This paper aims to describe and illustrate the new species, update generic diagnosis and give an identification key to known species of the genus Hardybodes. Material examined -Holotype (male) and one paratype (male): Philippines, Luzon Island, boundary between Laguna and Quezon Provinces, University of the Philippines Land Grant, nest in soil of unknown species of ants (Formicidae) (the nest is located by following major ant trails), extracted with Berlese funnel, 23.I.2016 (collected by R. Garcia, J. Naredo and H. Klompen).
Methods -Specimens were mounted in lactic acid on temporary cavity slides for measurement and illustration. Body length was measured in lateral view, from the tip of the rostrum to the posterior edge of the ventral plate. Notogastral width refers to the maximum width of notogaster. 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-tibia-tarsus (famulus included). Formulas for leg solenidia are given in square brackets according to the sequence genu-tibia-tarsus. Drawings were made with a camera lucida using a Leica transmission light microscope "Leica DM 2500". Morphological terminology used in this paper follows that of F. Grandjean: see Travé and Vachon (1975) for references, Norton (1977) for leg setal nomenclature, and Norton and Behan-Pelletier (2009), for overview.
The following collections are used: SMNH -Senckenberg Museum of Natural History, Görlitz, Germany; TSUMZ -Tyumen State University Museum of Zoology, Tyumen, Russia.
Juvenile instars -Not known.