New Oppiidae (Acari, Oribatida) from Chile

A BSTRACT — Two new species of oribatid mites of the family Oppiidae (Oribatida, Oppioidea), belonging to the genera Lanceoppia and Rhinoppia , are described from Sphagnum magellanicum from a swamp in the vicinity of Punta Arenas in Chile. Lanceoppia ( Bicristoppia ) archicostulata n. sp. is morphologically similar to L. ( Bicristoppia ) bicristata Hammer, 1962(b), but differs by the well-developed transcostula, the presence of a median indentation on the rostrum and by setae la and lm being the longest of all notogastral setae. Rhinoppia ( Rhinoppia ) paraundulata n. sp. is morphologically similar to R. ( Rhinoppia ) undulata (Mahunka and Mahunka-Papp, 2010), but differs by the long notogastral setae, the presence of longitudinal ridges in the interbothridial region, ﬁve pairs of genital setae and by the interlamellar setae being distinctly longer than rostral and lamellar setae. An identiﬁcation key to known species of Lanceoppia ( Bicristoppia ) is given.


INTRODUCTION
This work is a part of the continuing study of the Chilean oribatid mite fauna (Acari, Oribatida) by the author (Ermilov and Khaustov 2015;Ermilov and Weigmann 2015;Ermilov 2016). Mites were collected during a one-month expedition to southern Chile in November 2014, organized by the Tyumen State University (Tyumen, Russia). This paper includes data on new taxa of the family Oppiidae. Two new species, belonging to the genera (subgenera) Lanceoppia (Bicristoppia) Subías, 1989 and Rhinoppia (Rhinoppia) Balogh, 1983 were discovered. The aim of this paper is to describe and illustrate these taxa.
Lanceoppia (Bicristoppia) was proposed by Subías (Subías and Balogh 1989) with Oppia bicristata Hammer, 1962(b) as type species. Currently, the subgenus comprises five species, which are distributed in the southern subtropics (Súbias 2004(Súbias , online version 2016. Only one species of this subgenus was recorded in Chile, L. (Bicristoppia) binodosa (Hammer, 1962a). The species herein described follows the following subgeneric characters (based on data from Súbias and Balogh 1989; including our additions): Lanceoppiinae with rostrum rounded or with median indentation; costulae and/or transcostula present or absent, if present -with quadrangular or arch-lake configurations; interbothridial region with one pair of strong tubercles; bothridial setae fusiform, lanceolate or bacilliform; 9 or 10 pairs of notogastral setae, setae c minute or represented by alveoli; setae la inserted laterally to lm; six pairs of genital setae; adanal lyrifissures inverse apoanal.
Rhinoppia (Rhinoppia) was proposed by Balogh (1983) with Oppia nasuta Moritz, 1965 as type species. Currently, the subgenus comprises 36 species and two subspecies, which have a cos-mopolitan distribution, except the Antarctic and Oriental regions (Súbias 2004(Súbias , online version 2016. Some divergences exist in literature as Miko (2006) considers Rhinoppia as a subgenus of the genus Oppiella, Jacot. Clearly, additional research is needed to clarify the systematic placement of this genus. Thus, the classification of Subías was herein followed. No species of this subgenus is known from Chile. The species herein described follows the following subgeneric characters (based on data from Balogh 1983;Súbias andMínguez 1985 -as for Medioppia Súbias andMínguez, 1985;Mahunka 1987-as for Kunoppia Mahunka, 1987Súbias and Balogh 1989; including our additions): Medioppiinae with rostrum rounded, pointed, tripartite or median incision; costulae and transcostula absent; interbothridial region with ridges or tubercles; bothridial setae with dilated heads, ciliate unilaterally; lamellar setae inserted nearer to interlamellar setae than to rostral setae; anterior protruding of notogaster and cristae usually developed; 10 pairs of notogastral setae, c not shorter than others; setae la inserted antero-laterally or anteriorly to lm; four or five pairs of genital setae; adanal setae ad 1 in postanal position; adanal lyrifissures paraanal.
In addition to the description of the two new species, an identification key to known species of Lanceoppia (Bicristoppia) in the world is given.

MATERIALS AND METHODS
Material -The collection locality and habitat for each new species are given in the respective "Material examined" section.
Methods -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 trochanterfemur-genu-tibia-tarsus (famulus included). Formulas for leg solenidia are given in square brackets according to the sequence genu-tibia-tarsus. 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. Drawings were made with a camera lucida using a Carl Zeiss transmission light microscope "Axioskop-2 Plus". DESCRIPTIONS Lanceoppia (Bicristoppia) archicostulata n. sp. (Figures 1-3 Description -Measurements -Very small species. Body length: 237 (holotype, female), 233, 241 (two paratypes: one female and one male); notogaster width: 135 (holotype), 131, 143 (two paratypes).
Type deposition -The holotype is deposited in the collection of the Senckenberg Institution, Görlitz, Germany; two paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.
Etymology -The specific name archicostulata refers to the costulae and transcostula, which form the arch-like structure on the prodorsum.
Remarks -Lanceoppia (Bicristoppia) archicostulata n. sp. is morphologically most similar to L. (Bicristoppia) bicristata (Hammer, 1962(b)) from Argentina in having costulae, long notogastral setae and lanceolate bothridial setae. However, the new species differs from the latter by the well-developed transcostula (vs. transcostula absent), the presence of a median indentation on the rostrum (vs. rostrum rounded) and by setae la and lm being the longest on the notogaster (vs. dorsal notogastral setae similar in length).  (Hammer, 1962(b)). Distribution: Argentina.
Integument -Body color light brownish. Body surface smooth, but lateral sides (between bothridia and pedotecta II and III) with tuberculate cerotegument (diameter of tubercles up to 4).
Type deposition -The holotype is deposited in the collection of the Senckenberg Institution, Görlitz, Germany; two paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.
Etymology -The specific name paraundulata refers to the similarity between the new species to the species Rhinoppia (Rhinoppia) undulata (Mahunka and Mahunka-Papp 2010).
Remarks -Rhinoppia (Rhinoppia) paraundulata n. sp. is morphologically most similar to R. (Rhinoppia) undulata (Mahunka and Mahunka-Papp 2010) from Hungary in having an inverse trapezoid indentation of the rostrum. However, the new species differs from the latter by the long notogastral setae (vs. short), the presence of longitudinal ridges in the interbothridial region (vs. ridges transversely oriented) and five pairs of genital setae (vs, six pairs), and by the interlamellar setae distinctly longer than rostral and lamellar setae (vs. interlamellar, lamellar and rostral setae similar in length).