Pergalumna pietertheroni, Ermilov & Khaustov, 2019

Ermilov, Sergey G. & Khaustov, Alexander A., 2019, New Galumnoidea (Acari, Oribatida) from Tanzania, Zootaxa 4545 (4), pp. 531-547 : 533-534

Pergalumna pietertheroni sp. nov.

( Figs 14–25 , 41, 42 )

Diagnosis. Body size: 315–348 × 215–249. Body surface microgranulate. Rostral, lamellar and interlamellar setae short, thin, smooth, ro longest. Bothridial setae long, setiform, smooth. Dorsosejugal suture present. With three pairs of rounded porose areas, A1 absent. Porose areas Aa located between la and lm, closer to la. Median pore absent. Epimeral setal formula: 3–1–3–3. Epimeral and anogenital setae short, thin, smooth. Postanal porose area elongate oval.

Description. Measurements. Body length: 332 (holotype), 315–348 (five paratypes); notogaster width: 232 (holotype), 215–249 (five paratypes). Females larger than males: 348 × 249 versus 315–332 × 215–232.

Integument ( Fig. 41 ). Body color pale yellowish. Body surface (including subcapitular mentum and genital and anal plates) densely microgranulate (diameter of granules less than 1).

Prodorsum ( Figs 14, 15 , 19 , 42 ). Rostrum rounded. Lamellar and sublamellar lines thin, parallel, curving backwards at ventral ends. Prodorsal leg niches and lateral ridges of prodorsum well developed. Rostral (20–28), lamellar (8) and interlamellar (12) setae setiform, thin, smooth. Insertions of lamellar setae clearly distanced from lamellar lines. Bothridial setae (90–102) setiform, smooth. Exobothridial setae and their alveoli absent. Sejugal porose areas (12–16 × 4) elongate oval, transversely oriented, located posterolateral to interlamellar setae. Dorsophragmata distinctly elongated.

Notogaster ( Figs 14 , 19–21 ). Dorsosejugal suture present, simple. With 10 pairs of setal alveoli and three pairs of rounded porose areas (Aa, 8–10; A2, 6–8; A3, 4–6), A1 absent. Porose areas Aa located between la and lm, closer to la. Median pore absent. All lyrifissures distinct, im located anterolateral to A1, ip between p 1 and p 2 and closer to p 1, ih anterior to p 3, ips posterior to p 3. Opisthonotal gland openings located lateral to A2. Circumgastric sigillar band present, but poorly visible.

Gnathosoma ( Figs 16–18 ). Subcapitulum size: 106–110 × 90–94. Subcapitular setae setiform, smooth, a (20–28) longer than m (12) and h (4–6); a thickest, h thinnest. Adoral setae (10–12) setiform, heavily barbed. Length of palps 73–77. Postpalpal setae (6) spiniform, smooth. Length of chelicerae 127–131. Cheliceral setae setiform, barbed, cha (41–45) longer than chb (24–26). Trägårdh’s organ of chelicerae long, elongate triangular.

Epimeral and lateral podosomal regions ( Figs 15 , 19 ). Anterior tectum of epimere I smooth. Pedotecta I broadly rounded, pedotecta II triangular in ventral view. Discidia triangular. Epimeral setal formula: 3–1–3–3. Epimeral setae (4–6) setiform, thin, smooth. Circumpedal carinae (slightly developed in mediodistal part) of medium length, directed to insertions of setae 3b, but reaching them.

Anogenital region ( Figs 15 , 19–21 , 41 ). Six pairs of genital, one pair of aggenital, two pairs of anal and three pairs of adanal setae similar in length (4–6), setiform, thin, smooth. Anterior edge of genital plates with two setae. Aggenital setae equally distanced from genital and anal plates. Adanal lyrifissures located close and parallel to anal plates. Adanal setae ad 1 posterior, ad 2 posterolateral, ad 3 lateral to anal aperture; ad 3 anterolateral to iad. Distance ad 1 – ad 2 shorter than ad 2 – ad 3. Postanal porose area elongate oval (8–12 × 4–6).

Legs ( Figs 22–25 ). Median claw with basal tooth, distinctly thicker than laterals, all slightly barbed on dorsal side. Porose areas on all femora and on trochanters III, IV poorly visible. 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]; homologies of setae and solenidia indicated in Table 1. Famulus on tarsi I inserted anterior to solenidia ω 1 and ω 2. Solenidion on tibiae IV inserted in their middle part.

Type deposition. The holotype and two paratypes are deposited in the collection of SMNH. Three paratypes are deposited in the collection of TSUMZ .

Etymology. The specific name is dedicated to our friend and colleague, well-known acarologist, Dr. Pieter Theron (North-West University, Potchefstroom, South Africa).

Remarks. In having dorsosejugal suture, three pairs of rounded notogastral porose areas, setiform bothridial setae and short rostral, lamellar and interlamellar setae, Pergalumna pietertheroni sp. nov. is morphologically most similar to Pergalumna tanzanica Mahunka, 1984 from Tanzania (see Mahunka 1984 b), but clearly differs from the latter species by the morphology of bothridial setae (smooth versus heavily, unilaterally ciliate) and position of porose areas Aa (located closer to la versus equally distanced from la and lm).

Figures

FIGURES 14–18. Pergalumna pietertheroni sp. nov., adult: 14—dorsal view; 15—ventral view (gnathosoma, legs and right pteromorph not shown); 16—subcapitulum, ventral view; 17—palp, left, paraxial view; 18—chelicera, left, paraxial view. Scale bar 50 µm (14, 15), 20 µm (16–18).

FIGURES 19–21. Pergalumna pietertheroni sp. nov., adult: 19—anterior part of body, lateral view (gnathosoma, pteromorph and legs not shown); 20—posterior part of body, lateral view; 21—posterior view. Scale bar 50 µm.

FIGURES 22–25. Pergalumna pietertheroni sp. nov., adult: 22—leg I, right, antiaxial view; 23—trochanter, femur and genu of leg II, right, ventroantiaxial view; 24—trochanter, femur and genu of leg III, left, antiaxial view; 25—leg IV, left, antiaxial view. Scale bar 20 µm.

FIGURES 38–45. Galumnoidea, adults, microscope images: 38—Pergalumna hugocoetzeeae sp. nov., prodorsal sculpturing and rostrum, dorsoanterior view; 39—Pergalumna hugocoetzeeae sp. nov., dorsosejugal suture; 40—Pergalumna hugocoetzeeae sp. nov., dorsophragma and sejugal porose area; 41—Pergalumna pietertheroni sp. nov., granulate sculpturing in anogenital region; 42—Pergalumna pietertheroni sp. nov., dorsophragma and sejugal porose area; 43—Galumnella paraokinawana sp. nov., foveolate ornamentation in epimeral region; 44—Galumnella paraokinawana sp. nov., reticulate ornamentation between genital and anal apertures; 45—Galumnella paraokinawana sp. nov., claw of leg tarsus II.