Stictozetes ihaguensis, 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 : 97-99

Stictozetes ihaguensis sp. nov.

( Fig. 4 )

Diagnosis. Body size: 298–332 × 232–249. Body surface granulate. Rostral seta long, setiform, slightly barbed. Lamellar seta short, setiform, slightly barbed. Interlamellar seta minute. Bothridial seta long, with elongate, narrowly unilaterally dilated, barbed head, pointed apically. Dorsosejugal suture complete. With three pairs of rounded notogastral porose areas. Median pore represented by 2–4 foveae. Epimeral and anogenital setae short, setiform, roughened. Circumpedal carina long. Postanal porose area absent.

Description of adult. Measurements. Body length: 315 (holotype, female), 315, 332, 298 (three paratypes, male and two female, respectively); notogaster width: 232 (holotype), 232, 249, 240 (three paratypes).

Integument. Body color brown. Body surface heavily granulate (diameter of granule up to 1). 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. 4A, C ). Rostrum rounded. Lamellar and sublamellar lines thin, parallel, curving backwards. Lateral structure N and ridges E, T well visible. Rostral (24–28) and lamellar (12–16) setae setiform, slightly barbed. Interlamellar seta (4–6) setiform, thin, smooth. Bothridial seta (73–77) with long stalk and elongate, narrowly unilaterally dilated, barbed head, pointed apically. Dorsosejugal porose area rounded (6), located posterolateral to interlamellar seta. Dorsophragma distinctly elongated longitudinally.

Notogaster ( Fig. 4A, C, D ). Dorsosejugal suture complete. Ten pairs of short (8–12), setiform, thin, smooth setae developed. Three pairs of rounded porose areas poorly visible (Aa and A1, 6–8; A3, 2–4). Porose area Aa removed from pteromorphal hinge, located between setae la and lm (clearly closer to lm). Median pore present in both sexes, represented by two (four in one female) foveae, located between h 2. Opisthonotal gland opening and all lyrifissures (except ip not observed) distinct: gla located lateral to A1 and removed from it; im anterolateral to A1 and removed from it; ih and ips close to each other, anterior to p 3.

Gnathosoma. Generally, similar to that of Pilogalumna hogsbackensis sp. nov. Size of subcapitulum: 73 × 65. Subcapitular (a, 16; m, 12; h, 6–8) and adoral (8) setae setiform, roughened; a thicker than others. Length of palp: 57. Postpalpal seta (4) thorn-like, smooth. Length of chelicera: 94. Cheliceral setae (cha, 36; chb, 24) setiform, barbed.

Epimeral and lateral podosomal regions ( Fig. 4B, C ). Epimeral setal formula: 1-1-1-3. Setae (8–12) setiform, thin, roughened; 2a removed from median region. Pedotectum II rounded in ventral aspect. Discidium triangular. Circumpedal carina long, thick, directed to PdI.

Anogenital region ( Fig. 4 B–D). Genital (6–8), aggenital (10–12), anal (10–12), and adanal (10–12) setae setiform, thin, roughened. Anterior edge of genital plate with three 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. Postanal porose area absent.

Legs. Similar to that of Pilogalumna hogsbackensis sp. nov.

Material examined. Holotype (female) and three paratypes (one male and two 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 coniferous litter, 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); three 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 ihaguensis , is derived from the Xhosa word, ‘ihagu’, meaning ‘pig’ or ‘hog’. Hogsback is supposedly named after one of the mountain peaks overlooking the town which resembles a hog’s back.

Remarks. Stictozetes ihaguensis sp. nov. is morphologically most similar to Stictozetes scaber ( Berlese, 1916) from Somali in the presence of bothridial seta with dilated head and minute lamellar seta, and the absence of reticulate pteromorph and sexual dimorphism in presence of median pore and notogastral porose areas, but differs from the latter by the bothridial seta with narrowly dilated bothridial head (versus broadly dilated) and the presence of median pore (versus absent).

Figures

FIGURE 4. Stictozetes ihaguensis 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 50 μm.