Setoppia paraquattuor, Ermilov & Hugo-Coetzee & Khaustov, 2020

Ermilov, Sergey G., Hugo-Coetzee, Elizabeth A. & Khaustov, Alexander A., 2020, Contribution to the knowledge of the oribatid mite genus Setoppia (Acari, Oribatida, Oppiidae), with description of a new species from South Africa, Acarologia 60 (4), pp. 892-902 : 894-897

Setoppia paraquattuor n. sp.

Zoobank: 3CCF98C5-C43B-4D7D-9BC7-57FA7CAB91BF

( Figures 1 , 2 )

Diagnosis — Body size: 381–465 × 215–249. Rostrum tripartite. Rostral, lamellar and interlamellar setae long, setiform, barbed; in shorter than ro and le. Bothridial seta very long, setiform, shortly ciliate. Interbothridial region with two pairs of muscle sigillae and two pairs of interbothridial tubercles. Notogastral seta c minute; h 1 and h 3 very short, setiform, smooth; p 1, p 2 and p 3 of medium length, setiform, slightly barbed; la, lm, lp, and h 2 long, subequal in length, setiform, barbed, inserted in two longitudinal rows. Epimeral and anogenital setae setiform, slightly barbed. Discidium not observed.

Description — Measurements – Body length 415 (holotype), 381–465 (nine paratypes); body width 215 (holotype), 215–249 (nine paratypes). No distinct difference between male and female in body size.

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).

Prodorsum ( Figs 1A, 1C ) – Rostrum tripartite, teeth small, tightly pressed to each other, incision between teeth vary narrow, median tooth smallest or reduced. Rostral (53–61), lamellar (53–61) and interlamellar (41–49) setae setiform, barbed; le equally removed from ro and in. Exobothridial seta (20) setiform, thin, slightly barbed. Bothridial seta (184–196) setiform, shortly ciliate. Interbothridial region with two pairs of muscle sigillae and two pairs (anterior and posterior) of interbothridial tubercles. Postbothridial tubercle slightly developed. Longitudinal row, comprising several muscle sigillae, present in front of the bothridium.

Notogaster ( Figs 1A–1C ) – Anterior border convex medially. Ten pairs of notogastral setae present: c (4), h 1 (8–12) and h 3 (8–12) setiform, thin, smooth; p 1 (24–28), p 2 (16–20) and p 3 (16–20) setiform, thin, slightly barbed; la, lm, lp, and h 2 (114–135) setiform, barbed, inserted in two longitudinal rows. All notogastral lyrifissures and opisthonotal gland opening, circumgastric scissure, and circumgastric sigillar band distinct.

Gnathosoma ( Figs 2A–2C ) – Subcapitulum longer than wide (86–94 × 69–77). Subcapitular setae setiform, barbed, a (22–24) shorter than m (28–32) and h (28–32). Adoral seta (6) setiform, thin, smooth. Palp (61–65) with setation 0­2­1­3­8(+1 solenidion). Solenidion swollen distally and connected with seta ul′. Postpalpal seta (4) spiniform, smooth. Chelicera (86–94) with two setiform, barbed setae, cha (26–28) longer than chb (18–20). Trägårdh’s organ of chelicerae elongate triangular.

Epimeral and lateral podosomal regions ( Figs 1B, 1C ) – All epimeral setae setiform, slightly barbed, 1b, 1c, 3b, and 3c (45–49) longer than 1a, 2a and 3a (16–20) and others (24–28). Discidium not observed.

Anogenital region ( Figs 1B, 1C ) – Six pairs of genital (g 1, 14–16; others, 10–12), one pair of aggenital (30–32), three pairs of adanal (30–32) and two pairs of anal (22–24) setae setiform, slightly barbed. Adanal lyrifissure diagonal, close and lateral to anal aperture.

Legs ( Figs 2D–2G ) – Leg claw smooth. Porose area on femora I­IV slightly visible. Formulas of leg setation and solenidia: I (1­5­2­4­20) [1­2­2], II (1­5­2­4­16) [1­1­2], III (2­3­1­3­15) [1­1­0], IV (1­2­2­3­12) [0­1­0]; homology of setae and solenidia indicated in

Table 1 . Setae p setiform on tarsi I, and very short, conical on tarsi II­IV. Famulus of tarsus I erect, slightly swollen and blunted distally, inserted between solenidia 1 ω and ω 2. Solenidia ω 1 on tarsi I, ω 1 and ω 2 on tarsi II and σ on genua III bacilliform, other solenidia setiform.

Material examined — Holotype (male) and nine paratypes (two males and seven females): South Africa, Golden Gate Highlands National Park , 28°31′S, 28°39′E, ~ 1900 m a.s.l., soil near termite nests of Trinervitermes trinervoides , 11.IX.2019 (collected by V.A. Khaustov, S.G. Ermilov, E.A. Hugo­Coetzee and A.A. Khaustov).

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 ~ 88, 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).

Figures

Figure 1 Setoppia paraquattuorn. sp., adult: A – dorsal view (legs omitted); B – ventral view (gnathosoma and legs omitted); C – lateral view (gnathosoma and legs omitted). Scale bar 100 μm.

Figure 2 Setoppia paraquattuorn. sp., adult: A – subcapitulum, ventral view; B – palp, left, paraxial view; C – chelicera, left, paraxial view; D – leg I, right, antiaxial view; E – leg II (tarsus omitted), right, antiaxial view; F – leg III (tarsus omitted), left, antiaxial view; G – leg IV, left, antiaxial view. Scale bar 20 μm (A–C), 50 μm (D–G).