Perscheloribates paratzitzikamaensis n. sp., with supplementary descriptions of Scheloribates elegans and Monoschelobates parvus (Acari, Oribatida, Scheloribatidae) from Ecuador

A new oribatid mite species, Perscheloribates paratzitzikamaensis n. sp., is described from Ecuador. This species is morphologically similar to Perscheloribates tzitzikamaensis (Pletzen, 1965) from South Africa, however, it differs from the latter by the smaller body size, longer notogastral setae p1, the absence of a translamellar line and prolamellar lines represented only by short basal part. The supplementary descriptions of Scheloribates elegans Hammer, 1958 and Monoschelobates parvus Balogh and Mahunka, 1969 are presented on the basis of Ecuadorian specimens.


INTRODUCTION
The present study is based on the oribatid mite material collected by Dorothee Sandmann (second author) and Franca Marian (third author) in 2008-2010 from Ecuador. This paper includes the data on the family Scheloribatidae (Acari, Oribatida).
In the course of the identification of scheloribatid mites from Ecuador we found one new species belonging to the genus Perscheloribates Hammer, 1973. The primary purpose of our paper is to describe and illustrate this species. Perscheloribates is a genus that was proposed by Hammer (1973) with Perscheloribates clavatus Hammer, 1973 as type species. Currently, it comprises more than 40 species, which are distributed in tropical regions. The main generic characters are summarized by Hammer (1973), Corpus-Raros (1980) and Balogh andBalogh (1990, 1992), including our additional opinion: rostrum rounded (rarely pointed or with incisions); rostral setae inserted dorso-laterally or laterally on prodorsum; interlamellar setae long or medium size; sensilli with dilated head (exceptionally setiform); prolamellar lines present or absent; pteromorphae well developed; notogaster with 10 pairs of setae, which are short (rarely medium size) or represented by alveoli; genital plates with four setae; aggenital setae present; lyrifissures iad in paraanal position; tarsi of all legs with one claw. An identification key for the Neotropical species of Per-scheloribates has been presented earlier (Balogh andBalogh 1990, 2002).
The second purpose of our paper is to present detailed supplementary descriptions of Scheloribates elegans Hammer, 1958 and Monoschelobates parvus Balogh and Mahunka, 1969 on the basis of Ecuadorian specimens. Scheloribates elegans was briefly described by Hammer (1958) from Bolivia. Later, it was briefly redescribed by Corpus-Raros (1980) from the Philippines. Monoschelobates parvus was briefly described by Balogh and Mahunka (1969; see also Balogh and Balogh 1990)  Specimens were studied in lactic acid, mounted in temporary cavity slides for the duration of the study and then stored in 90% alcohol in vials. 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. The length of body setae was measured in lateral aspect. Positions of lyrifissures (ia, im, ip, ih, ips), opisthonotal gland openings (gla), and morphology of subcapitulum, palps, chelicerae, leg segments, leg setae and solenidia resembled that in other Scheloribatidae (Coetzer 1967(Coetzer -1968Ermilov et al. 2011;Ermilov and Kalúz 2012), therefore, we do not give detailed data in this paper. All body measurements are given in micrometers. Formulae of leg setation are given according to the sequence trochanter-femur-genu-tibia-tarsus (famulus included). Formulae of leg solenidia are given (in square brackets) according to the sequence genu-tibia-tarsus. General terminology used in this paper follows that summarized by Coetzer (1967Coetzer ( -1968, and Norton and Behan-Pelletier (2009).
Anogenital region -Four pairs of genital (g 1 , 12 -20, g 2 -g 4 , 6 -12), one pair of aggenital (ag, 6 -12), two pairs of anal (an 1 , an 2 , 6 -12) and three pairs of adanal (ad 1 -ad 3 , 6 -12) setae thin, smooth. Lyrifissures iad in paraanal position. Type deposition -The holotype is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; two paratypes are deposited in the collection of the Siberian Zoological Museum, Novosibirsk, Russia; two paratypes are in the personal collection of the first author.
Etymology -The prefix para is Latin meaning "near" and refers to the similarity between the new species and the species Perscheloribates tzitzikamaensis (Pletzen, 1965).
Also, in having the long notogastral setae p 1 (other setae represented by alveoli), Perscheloribates paratzitzikamaensis n. sp. is similar to Perscheloribates aculeatus (Hammer, 1961) from Peru (see Hammer 1961), however, it differs from the latter by the spindle-form sensilli (versus fusiform in P. aculeatus) and the rounded rostrum (versus pointed in P. aculeatus).  Integument -Body color light brown. Body surface smooth.
Remarks -Ecuadorian specimens of Monoschelobates parvus are similar in general appearance to Brazilian specimens (Balogh and Mahunka 1969;Balogh and Balogh 1990), but there is a clear difference: prolamellar lines present versus absent in Brazilian specimens. Sometimes presence or absence of prolamellar lines or their partial development can vary in specimens of one species in Scheloribatidae: for example, prolamellar lines in Scheloribates fimbriatus Thor, 1930-present (see Subbotina 1978, developed partially (Mahunka 1987), indistinctly visible or absent (data of first author, based on specimens from Western Europe); similar situation is known for Scheloribates (Bischeloribates) mahunkai Subías, 2010 (Ermilov 2013). Hence, we assume this difference to represent intraspecific variability in the case of M. parvus.