Contributions to the knowledge of oribatid mites (Acari, Oribatida) of Indonesia. 3. The genus Galumna (Galumnidae) with description of a new subgenus and seven new species

Abstract Seven new species of oribatid mites of the genus Galumna are described from litter and soil materials of Sumatra, Indonesia. A new subgenus, Galumna (Atypicogalumna) subgen. n., is proposed; it differs from all galumnid genera and subgenera by the simultaneous presence of porose areas and sacculi on the notogaster (vs. either porose areas or sacculi present). Galumna (Galumna) calva Starý, 1997 is recorded for the first time in the Oriental region, and Galumna (Galumna) sabahna Mahunka, 1995 is recorded for the first time in the Indonesian fauna.


Introduction
This work is a part of a continuing study of the Indonesian fauna of oribatid mites (see Ermilov et al. 2015c, d), and includes data on the genus Galumna Heyden, 1826 (Acari, Oribatida, Galumnidae). During taxonomic identification, ten species were found belonging to four subgenera: G. (Atypicogalumna) subgen. n., G. (Galumna) Heyden, 1826, G. (Cosmogalumna) Aoki, 1988 and G. (Neogalumna) Hammer, 1973. The main goal of the paper is to present data on the specific localities, notes on new records and overall known distribution of registered taxa, and to describe and illustrate a new subgenus and seven new species.

Material and methods
Exact collection locality and habitat are given in the respective "Material examined" section for each species.
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 of the ventral plate. Notogastral width refers to the maximum width 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-tibia-tarsus (famulus included). Formulas for leg solenidia are given in square brackets according to the sequence genu-tibia-tarsus. General terminology used in this paper follows that of Grandjean (summarized by Norton and Behan-Pelletier 2009). Drawings were made with a camera lucida using a Carl Zeiss transmission light microscope "Axioskop-2 Plus". located between A3. All lyrifissures (ia, im, ip, ih, ips) distinct, im located anteriorly and nearly to A1. Opisthonotal gland openings located antero-laterally to A2.
Type deposition. The holotype is deposited in LIPI (Indonesian Institute of Science) Cibinong, Indonesia; two paratypes are deposited in the collection of the Senckenberg Museum, Görlitz, Germany; three paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.
Type deposition. The holotype is deposited in LIPI (Indonesian Institute of Science) Cibinong, Indonesia; two paratypes are deposited in the collection of the Senckenberg Museum, Görlitz, Germany; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.
Type deposition. The holotype is deposited in LIPI (Indonesian Institute of Science) Cibinong, Indonesia; two paratypes are deposited in the collection of the Senckenberg Museum, Görlitz, Germany; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.
Etymology. The specific name is dedicated to our friend and colleague, acarologist, Dr. Ladislav Miko (Czech University of Life Sciences Prague, Charles University in Prague, Prague, Czech Republic).
Remarks. Galumna (Galumna) mikoi sp. n. is morphologically most similar to G. Integument. Body color brown. Body surface, pteromorphs, genital and anal plates punctate (visible in dissected specimens). Subcapitular mentum smooth. Transverse band of strong, branched cerotegumental ridges developed in the middle part of the notogaster and between the genital and anal plates. These ridges comparatively short and not forming a clear reticulate pattern, only a few cells present exeptionally.
Legs. Morphology of leg segments, setae and solenidia typical for Galumna (Cosmogalumna) (see Ermilov et al. 2011;Ermilov and Anichkin 2013). Tridactylous, claws smooth. Formulas of leg setation and solenidia are similar to Galumna (Atypicogalumna) corpuzrarosae sp. n. (Table 1). Solenidion φ of tibiae IV inserted dorsally at about 2/3 length of segment.   Type deposition. The holotype is deposited in LIPI (Indonesian Institute of Science) Cibinong, Indonesia; two paratypes are deposited in the collection of the Senckenberg Museum, Görlitz, Germany; six paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.
Etymology. The specific name areticulata refers to the absence of clear reticulate pattern on the body.
Remarks. Galumna (Cosmogalumna) areticulata sp. n. is morphologically most similar to G. (C.) praeoccupata Subías, 2004 from southern China and Vietnam (see Aoki and Hu 1993; including personal data based on the Vietnamese specimens) in having transverse band of reticulation in the middle part of the notogaster and between genital and anal plates, and the absence of striate and reticulate pattern on the prodorsum and pteromorphs. However, the new species differs from the latter by the presence of strong, branched cerotegumental ridges, which do not form a reticulate pattern (vs. distinct reticulate pattern, represented by small, numerous, dense cells in G. Integument. Body color brown. Body surface, pteromorphs, genital and anal plates, and subcapitular mentum punctate. Reticulate pattern in the middle part of notogaster present, cells large and not numerous. Reticulate pattern between genital and anal plates represented by small, numerous, dense cells. Prodorsum. Rostrum rounded. Lamellar and sublamellar lines parallel, curving backwards. Rostral (16) and lamellar (10-12) setae thin, indistinctly barbed. Interlamellar setae represented by alveoli. Bothridial setae (49-53) clavate, with long stalk and short head, rounded and barbed distally. Exobothridial setae and their alveoli absent. Porose areas Ad oval, transversally oriented (14-16 × 4-6).
Type deposition. The holotype is deposited in LIPI (Indonesian Institute of Science) Cibinong, Indonesia; one paratype is deposited in the collection of the Senckenberg Museum, Görlitz, Germany; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.   Notogaster. Anterior notogastral margin developed. Dorsophragmata of medium size, elongated longitudinally. Four pairs of porose areas rounded, with distinct margins: Aa (16-24) usually slightly larger than A1, A2 and A3 (all 12-16). Notogastral setae represented by 10 pairs of alveoli, however, based on their localization, la absent and c x present. Median pore absent in all specimens. All lyrifissures distinct, im located between lm and A1. Opisthonotal gland openings located laterally to A1.
Type deposition. The holotype is deposited in LIPI (Indonesian Institute of Science) Cibinong, Indonesia; two paratypes are deposited in the collection of the Senckenberg Museum, Görlitz, Germany; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.  Etymology. The specific name specifica refers to the specific set of notogastral alveoli (la absent, c x present).
Remarks. Galumna (Neogalumna) specifica sp. n. is morphologically most similar to G. (N.) tolstikovi Ermilov & Anichkin, 2014 from Vietnam (see Ermilov and Anichkin 2014b) in having straight lamellar lines, short prodorsal setae, setiform bothridial setae, setal alveoli c x and striate genital plates. However, the new species differs from the latter by larger body size (498-531 × 348-365 vs. 381-415 × 265-298 in G. (N.)  Technology of Indonesia (RISTEK) for the research permit and the Indonesian Institute of Sciences (LIPI) and Ministry of Forestry (PHKA) for the collection permit, the village heads, local site owners, PT REKI and Bukit Duabelas National Park for granting access to their properties and the many colleagues and helpers for support in the field.
Financial support was provided by the German Research Foundation (DFG) in the framework of the collaborative German -Indonesian research project CRC990 (EFForTS). The taxonomic study on Galumnoidea was supported by the Russian Foundation for Basic Research (project: 15-04-02706 A).