Pergalumna (Pergalumna) amatholensis, Ermilov & Hugo-Coetzee & Khaustov, 2021

Ermilov, Sergey G., Hugo-Coetzee, Elizabeth A. & Khaustov, Alexander A., 2021, Three new species of oribatid mites of the family Galumnidae (Acari, Oribatida) from South Africa, Zootaxa 4920 (1), pp. 91-100 : 95-97

Pergalumna (Pergalumna) amatholensis sp. nov.

( Fig. 3 )

Diagnosis. Body size: 332–349 × 232–249. Rostral, lamellar and interlamellar setae long, setiform, barbed. Bothridial seta long, with elongate, unilaterally narrowly dilated, barbed head, pointed apically. Dorsosejugal suture complete. With four pairs of rounded notogastral porose areas. Median pore present. Epimeral and anogenital setae short, setiform, roughened. Circumpedal carina of medium length. Postanal porose area elongate oval.

Description of adult. Measurements. Body length: 332 (holotype, male), 332, 349 (two paratypes, male and female, respectively); notogaster width: 249 (holotype), 232, 249 (two paratypes).

Integument. Body color brown in holotype and one paratype and light yellowish in one paratype. Body surface microporose (visible under high magnification, × 1000). Lateral side of body between bothridium and acetabula I–IV with microgranulate cerotegument. Leg femora I–IV and trochanters III, IV partially tuberculate and striate.

Prodorsum ( Fig. 3A, C ). Rostrum rounded. Lamellar and sublamellar lines thin, parallel, curving backwards. Lateral structure N and ridges E, T well visible. Rostral (41–45), lamellar (41–45) and interlamellar (65–69) setae setiform, barbed. Bothridial seta (82–86) with long stalk and elongate, unilaterally narrowly dilated, barbed head, pointed apically. Dorsosejugal porose area elongate oval (16–20 × 4), transversely oriented, located posterolateral to interlamellar seta. Dorsophragma distinctly elongated longitudinally.

Notogaster ( Fig. 3A, C, D ). Dorsosejugal suture complete. With ten pairs of setal alveoli and four pairs of rounded porose areas (Aa, 14–16; A1, A2 and A3, 10–12). Porose area Aa located close to pteromorphal hinge, anterior to setal alveolus la. Median pore present in both sexes, located behind virtual line connected A1. Opisthonotal gland opening and all lyrifissures distinct: gla located close and lateral to A2; im between lm and A1 (equally removed from them); ip between p 1 and p 2 (equally removed from them); ih and ips close to each other, anterior to p 3.

Gnathosoma. Generally, similar to that of Pilogalumna hogsbackensis sp. nov. Size of subcapitulum: 90 × 82. Subcapitular (a, 16; m and h, 12) and adoral (8) setae setiform, roughened; a thicker than others. Length of palp: 65. Postpalpal seta (4) thorn-like, smooth. Length of chelicera: 110. Cheliceral setae (cha, 41; chb, 28) setiform, barbed.

Epimeral and lateral podosomal regions ( Fig. 3B, C ). Epimeral setal formula: 1-0-1-2. Setae (1a, 10; 3b, 12; 4a, 4b, 8) setiform, thin, roughened. Pedotectum II rounded in ventral aspect. Discidium triangular. Circumpedal carina of medium length, thin, directed to insertion of 3b, but not reaching them.

Anogenital region ( Fig. 3 B–D). Genital (6), aggenital (8), anal (8), and adanal (8) setae setiform, thin, roughened. Anterior edge of genital plate with two setae. Aggenital seta located between genital and anal apertures, closer to the former. Adanal lyrifissure located close and parallel to anal plate. Adanal setae ad 1 and ad 2 posterior, ad 3 lateral to iad and anal plate. Distance ad 1 – ad 2 shorter than ad 2 – ad 3. Unpaired postanal porose area elongate oval (18–20 × 4–6).

Legs. Identical to that of Pilogalumna hogsbackensis sp. nov. (see Table 1).

Material examined. Holotype (male) and two paratypes (one male and one female): South Africa, Amathole mountains in the Eastern Cape Province, Hogsback State Forest at the village of Hogsback , 32°35’21.6”S, 26°57’38.5’’E, indigenous Afro-montane mixed forest, in soil, 14.IX.2019 (collected by V. A. Khaustov, S.G. Ermilov, J.A. Neethling, E.A. Hugo-Coetzee, and A.A. Khaustov).

Type deposition. The holotype is deposited in the collection of the National Museum Bloemfontein, South Africa ( NMB); two paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia ( TSUMZ). All specimens are preserved in 70% solution of ethanol with a drop of glycerol .

Etymology. The specific name amatholensis refers to the Amathole mountains, where the new species was collected.

Remarks. Pergalumna amatholensis sp. nov. is morphologically most similar to Pergalumna distincta Liu & Wu, 2013 from northern China in the presence of bothridial setal head, median pore, long prodorsal setae, complete dorsosejugal suture, elongate oval postanal porose area, and four pairs of rounded notogastral porose areas, and the absence of body sculpturing and ornamentation, but differs from the latter by the smaller body size (332–349 × 232–249 versus 555 × 400), rounded rostrum (versus pointed), unilaterally dilated bothridial head (versus fusiform), one pair of notogastral porose areas Aa (versus two pairs), and localization of gla close to A2 and im removed from A1 (versus gla removed from A2 and im close to A1).

From other South African species/subspecies ( P. altera , P. elongata , P. incomperta , P. magnipora capensis , P. myrmophila , P. nervosa , and P. obvia ), the new species distinctly differs by the presence of one pair of rounded porose area Aa (versus two pairs of Aa or Aa elongate oval/triangular) and bothridial seta with elongate, narrowly unilaterally dilated head, pointed apically (versus setiform or clavate, rounded apically).

Note: Roman letters refer to normal setae, Greek letters to solenidia (except ɛ = famulus), Single quote (’) marks seta on anterior and double quote (”) seta on posterior side of the given leg segment. Parentheses refer to a pair of setae.

Figures

FIGURE 3. Pergalumna amatholensis sp. nov., adult: A—dorsal view; B—ventral view (gnathosoma and legs omitted); Clateral view (pteromorph, gnathosoma and legs omitted); D—posterior view (pteromorphs omitted). Scale bar 50 μm.