Contribution to the knowledge of the oribatid mite genus Gittella (Acari, Oribatida, Oppiidae), with description of a new species from Peru

A new species of the genus Gittella (Oribatida, Oppiidae) - G. kontschani n. sp. - is described, based on materials collected from upper soil and leaf litter in the primary evergreen lowland rainforest of Amazonian Peru. Generic diagnosis, an identification key, distribution, and habitats of all known species of Gittella are presented.


Introduction
The oribatid mite genus Gittella (Acari, Oribatida, Oppiidae) was proposed by Hammer (1961) with Gittella punctata Hammer, 1961 as type species. At present, the genus comprises seven species, which are distributed in the Neotropical region (Subías 2004(Subías , online version 2021. The main goals of the paper are: to describe and illustrate a new species of Gittella collected from Amazonian Peru; to summarize generic morphological traits; to provide an identification key and to present distribution and habitats of all known species of the genus.
Types are deposited in three institutions: the Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima, Peru (MUSM); the Tyumen State University Museum of Zoology, Tyumen, Russia (TSUMZ); and the SNSB-Bavarian State Collection of Zoology, Munich, Germany (ZSM).
Observation and documentation -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 gastronotum. Notogastral width refers to the maximum width of the notogaster in dorsal view. 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".
Integument -Body color light brown to brown. Body surface densely microgranulate (diameter of granule less than 1). Notogaster and anogenital region sparsely foveolate (diameter of foveola up to 8). Lateral part of body between bothridium and acetabula I-III densely tuberculate (diameter of tubercle up to 4).
Type material -Holotype (male) and 16 paratypes (11 males and five females). The holotype is deposited in the collection of the MUSM; two paratypes are deposited in the collection of the ZSM; 14 paratypes are deposited in the collection of the TSUMZ. All specimens are preserved in 70% solution of ethanol with a drop of glycerol.
Etymology -The species name kontschani is given in honour of our friend and colleague, the well-known acarologist Dr. Jenő Kontschán (Budapest, Hungary), for his invaluable contributions to the knowledge of the mite fauna of ACP Panguana.
Remarks -Gittella kontschani n. sp. is morphologically most similar to Gittella variabilis Ermilov, Sandmann, Marian and Maraun, 2013 in having foveolate notogaster and anogenital region, but differs from the latter by the smaller body length (481-531 versus 647-680), the relative length of prodorsal setae (ro ˃ le = in = ex versus in ˃ le = ro ˃ ex), and the absence (versus presence) of interlamellar and postbothridial tubercles.
Distinctive characters of the new species compared with other members of Gittella can be found in the identification key below.
Key to known species of Gittella  Mahunka, 1998.