Pilogalumna hogsbackensis, 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 : 92-95

Pilogalumna hogsbackensis sp. nov.

( Figs 1 , 2 )

Diagnosis. Body size: 481–547 × 348–398. Rostral and lamellar setae long, setiform, barbed. Interlamellar seta minute. Bothridial seta long, with elongate, narrowly unilaterally dilated, barbed head, pointed apically. Dorsosejugal suture interrupted medially. Notogastral seta short, setiform, smooth. With five pairs of notogastral porose areas, Aal, Aam, A1, and A2 rounded, A3 elongate oval. Median pore absent. Epimeral and anogenital setae short, setiform, roughened (except minute and smooth 1c). Circumpedal carina short. Adanal lyrifissure located close and diagonal to anal plate. Postanal porose area elongate oval.

Description of adult. Measurements. Body length: 481 (holotype, male), 481–547 (seven paratypes, three males and four females); notogaster width: 348 (holotype), 348–398 (seven paratypes). Females larger than males: 514–547 × 381–398 versus 481–498 × 348–365.

Integument. Body color brown. Body surface microporose (visible under high magnification, × 1000). Lateral part of prodorsum with some microtubercles. 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. 1A, C ). Rostrum rounded. Lateral structure N and ridges E, T well visible. Rostral and lamellar setae (45–49) setiform, barbed. Interlamellar seta (8) setiform, thin, smooth. Bothridial seta (110–114) with long stalk and elongate, narrowly unilaterally dilated, barbed head, pointed apically. Dorsosejugal porose area oval (14–16 × 6–8), transversely oriented, located posterolateral to interlamellar seta. Dorsophragma slightly elongated longitudinally.

Notogaster ( Fig. 1A, C, D ). Dorsosejugal suture interrupted medially. Ten pairs of short (4–6), setiform, thin, smooth setae developed. Five pairs of porose areas present: Aal, Aam, A1, and A2 rounded (10–14); A3 elongate oval (28–36 × 6–8). Porose area Aal located close to pteromorphal hinge, anterior to seta la. Median pore absent in both sexes. Opisthonotal gland opening and all lyrifissures distinct: gla located lateral to A1 and removed from it; im between Aam and A1 (clearly closer to A1); ip between p 1 and p 2 (clearly closer to p 1); ih and ips close to each other, anterior to p 3.

Gnathosoma ( Fig. 2 A–C). Size of subcapitulum: 114–118 × 94–102. Subcapitular (a, 24; m and h, 20) and adoral (12–14) setae setiform, barbed; a thicker than others. Length of palp: 86–90. Postpalpal seta (8) thorn-like, smooth. Length of chelicera: 143–147. Cheliceral setae (cha, 41–45; chb, 28) setiform, barbed.

Epimeral and lateral podosomal regions ( Fig. 1B, C ). Epimeral setal formula: 2-0-1-2. Setae setiform, thin, 1c (2) smooth, others (1a, 16–20; 3b, 20–24; 4a, 4b, 12–14) roughened. Pedotectum II rounded in ventral aspect. Discidium triangular. Circumpedal carina comparatively short, thin, reaching level of acetabula IV.

Anogenital region ( Fig. 1 B–D). Genital, aggenital, anal, and adanal setae (12) setiform, thin, roughened. Anterior edge of genital plate with two setae. Aggenital seta located between genital and anal apertures, slightly closer to the former. Adanal lyrifissure located close and diagonal to anal plate. Adanal setae ad 1 and ad 2 posterior, ad 3 (posterior to iad) lateral to anal plate. Distance ad 1 – ad 2 shorter than ad 2 – ad 3. Unpaired postanal porose area elongate oval (28–32 × 6–8).

Legs ( Fig. 2 D–G). Median claw distinctly thicker than lateral claws, all barbed on dorsal side. Formulas of leg setation and solenidia: I (1-4-3-4-20) [1-2-2], II (1-4-3-4-15) [1-1-2], III (1-2-1-3-15) [1-1-0], IV (1-2-2-3-12) [0- 1-0]; homology of setae and solenidia indicated in Table 1. Solenidion on tibia IV inserted in anterior part of the segment.

Material examined. Holotype (male) and seven paratypes (three males and four females): 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); seven 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 hogsbackensis refers to the place of origin, Hogsback State Forest.

Remarks. Pilogalumna hogsbackensis sp. nov. is morphologically most similar to Pilogalumna tenuiclava ( Berlese, 1908) from the Holarctic region and P. ornatula Grandjean, 1956 from the Mediterranean, Mexico and Ethiopia in the presence of minute interlamellar seta, long rostral and lamellar setae and elongate oval notogastral porose area A3, and the absence of sexual dimorphism, but differs from both by the elongate oval postanal porose area (versus very long, band-like) and narrowly unilaterally dilated bothridial head (versus lanceolate).

From other South African species ( P. bloemfonteinensis , P. kimberleyensis and P. variabilis ), the new species distinctly differs by the presence of minute interlamellar seta (versus long).

Figures

FIGURE 1. Pilogalumna hogsbackensis sp. nov., adult: A—dorsal view; B—ventral view (gnathosoma and legs omitted); C—lateral view (pteromorph, gnathosoma and legs omitted); D—posterior view (pteromorphs omitted). Scale bar 100 μm.

FIGURE 2. Pilogalumna hogsbackensis sp. nov., adult: A—subcapitulum, ventral view; B—chelicera, left, paraxial view; C—palp, left, antiaxial view; D—leg I (trochanter omitted), left, paraxial view; E—leg II, right, antiaxial view; F—leg III, left, antiaxial view; G—leg IV, left, antiaxial view. Scale bar 20 μm (A–C), 50 μm (D–G).