Contributions to the knowledge of oribatid mites of Indonesia. 1. The genus Allogalumna (Galumnidae) with descriptions of two new species (Acari, Oribatida)

Abstract Two new species of oribatid mites of the genus Allogalumna (Oribatida, Galumnidae) are described from litter and soil materials of Sumatra, Indonesia. Allogalumna indonesiensis sp. n. is morphologically most similar to Allogalumna borhidii Balogh & Mahunka, 1979, Allogalumna quadrimaculata (Mahunka, 1988), Allogalumna rotundiceps Aoki, 1996 and Allogalumna plowmanae Balogh & Balogh, 1983; however, the new species differs by having densely ciliate bothridial heads, larger body size and absence of a median pore. Allogalumna paranovazealandica sp. n. is morphologically most similar to Allogalumna novazealandica Hammer, 1968; however, the new species differs by the shorter body length and barbed and curving postero-laterad bothridial setae. The genus Allogalumna is recorded for the first time in the Indonesian fauna.


Introduction
At present, the oribatid mite fauna (Acari, Oribatida) of Indonesia is poorly known (Sellnick 1925(Sellnick , 1930Willmann 1929Willmann , 1932Csiszár 1961;Balogh and Mahunka 1968;Mahunka 1977Mahunka , 1989Mahunka , 1990Hammer 1979Hammer , 1981aHammer , 1981bHammer , 1982Aoki et al. 1994;Niedbała 2007Niedbała , 2008. This work is a part of a study on Indonesian oribatids and based on material which was collected in 2013 in the framework of the interdisciplinary project "Ecological and socioeconomic functions of tropical lowland rainforest transformation systems (Sumatra, Indonesia)". Litter and soil samples were taken along a land use gradient including rainforest, jungle rubber, rubber and oil palm plantations in Jambi Province. For more details on the study region and experimental design see Barnes et al. (2014).
This paper includes the data on taxa of Allogalumna Grandjean, 1936 (Galumnidae). During taxonomic identification, two new species of this genus were found. The main goal of the paper is to describe and illustrate these species under the names A. indonesiensis sp. n. and A. paranovazealandica sp. n.
Allogalumna is a genus that was proposed by Grandjean (1936) with Galumna alamellae Jacot, 1935 as type species. Based on updated generic diagnosis (Ermilov et al. 2013a), it comprises more than 40 1 species collectively having a cosmopolitan distribution; Allogalumna has not been reported before in the Indonesian fauna. An identification key to all known species of this genus was given by Akrami (2015), while additional keys to selective species were presented by Balogh and Balogh (2002) and Ermilov and Anichkin (2014).

Materials and methods
Exact collection locality and habitat are given in the respective "Material examined" section for each new 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. Formulae for leg setation are given in parentheses according to the sequence trochanter-femur-genu-tibia-tarsus (famulus included). Formulae 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).
Type deposition. The holotype is deposited in LIPI (Indonesian Institute of Science) Cibinong, Indonesia; three paratypes are deposited in the collection of the Senckenberg Museum, Görlitz, Germany; four paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.
Etymology. The specific name paranovazealandica refers to the morphological similarity of the new species to Allogalumna novazealandica Hammer, 1968. Remarks. Allogalumna paranovazealandica sp. n. is most similar to A. novazealandica Hammer, 1968 from New Zealand in having minute prodorsal setae, long bothridial setae with slightly dilated head, four pairs of rounded notogastral porose areas, median pore and elongated postanal porose area. However, the new species differs from the latter by the shorter body length (282-298 versus 400-410 in A. novazealandica) and barbed in medio-distal part and curving postero-laterad bothridial setae (versus smooth and straight, directed upwards-laterally in A. novazealandica).