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

A new species of the genus Setoppia (Oribatida, Oppiidae) is described from soil of Golden Gate Highlands National Park, South Africa. Setoppia paraquattuor n. sp. differs from Setoppia quattuor in having smaller lateral teeth and incision on the tripartite rostrum, shorter notogastral setae h3 and subequal sized la, lm, lp, and h2 setae. Summarized generic traits, identification key, distribution worldwide and in South Africa, and habitats of all known species of Setoppia are presented.


Introduction
During taxonomic identification of oribatid mites (Acari, Oribatida) from South African Golden Gate Highlands National Park, we found a new species, belonging to the genus Setoppia (family Oppiidae). The main goals of our paper are: to describe and illustrate this new species based on adults; to summarize generic morphological traits; to provide identification key to known species of Setoppia; to present data on distribution and habitats of representatives of the genus.
Integument (Figs 1A, 1C) -Body color light brown to brown. Body surface microporose (visible only under high magnification in dissected specimens, × 1000). Lateral part of rostrum foveolate (diameter of foveola up to 1). Lateral parts of body between bothridium and acetabula IIII with numerous cuticular granules (their diameter up to 4).

Leg
Tr Note: Roman letters refer to normal setae, Greek letters to solenidia (except ɛ = famulus). Single prime (' ) marks setae on the anterior and double prime (" ) setae on the posterior side of a given leg segment. Parentheses refer to a pair of setae.
Type deposition -The holotype is deposited in the collection of the NMB; nine 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 name paraquattuor refers to the similarity between the new species and Setoppia quattuor Kok, 1967. Remarks -The holotype and paratypes of S. quattuor, housed at NMB, were reexamined. It was observed that all types have a tripartite rostrum (incorrectly described and figured by Kok, 1967 as rounded), with wide lateral teeth, wide incision, and a medium sized middle tooth. With this new evidence, Setoppia paraquattuor n. sp. is morphologically most similar to Setoppia quattuor and S. tuberosa in having tripartite rostrum, very long bothridial seta, long notogastral setae la, lm, lp, and h 2 located in two longitudinal rows and other notogastral setae short. Setoppia paraquattuor n. sp. differs from S. quattuor by the smaller lateral teeth and incision in the rostrum, very short seta h 3 (versus longer), similar sized notogastral setae la, lm, lp, and h 2 (114-135) (versus setae of different sizes; la, h 2~8 8, lm~100, lp~130) and seta p 1 longer than p 2 and p 3 (versus p 1 , p 2 and p 3 subequal in size). The new species differs from S. tuberosa by the smaller or reduced middle tooth and incisions in the rostrum, smaller body size (381-465 × 215-249 versus 475-533 × 270-303) and the presence of long interlamellar seta (versus very short) and two pairs of interbothridial tubercles (versus four or five pairs).
Neotropical region (two species). Setoppia angustopili was originally described from Chile and later recorded in Argentina. It was recorded from moss and fern on moist mouldering soil in forests of bamboo and tall trees in the Andes Mountains near Peulla in central Chile (Hammer 1962) and from soil, leaf litter and pitfall traps in Austrocedrus chilensis and Nothofagus forests of northwestern Patagonia (Kun et al. 2010), and from an unknown collecting site in Argentina in the northwestern Patagonia (Balogh & Csiszár 1963). Setoppia parrillarensis was described from swamp moss near Laguna Parrillar National Park in southern Chile (Ermilov 2019).
Australasian region (seven species). Six species of Setoppia (S. bornemisszai, S. compressa, S. longisetosa, S. strinovichi, S. toroki, and S. toxotes) were found and described in Australia: S. bornemisszai, S. strinovichi, S. toroki, and S. toxotes were registered from litter in rainforest near Urbenville village in eastern Australia (Balogh 1982); S. compressa from wet sclerophyllous rain forest on Mount Glorious in Queensland in northeastern Australia, without designation of sample (Balogh & Mahunka 1975); and S. longisetosa from black rock, dry sclerophyllous country in Queensland in northeastern Australia, without designation of sample (Balogh & Mahunka 1975). Setoppia mahunkai was recorded from Selaginella vegetation and dead leaves under treeferns of native forest on the west coast of the North Island near New Plymouth in New Zealand (Hammer 1968).