Phyllhermannia bimaculata Hammer, 1979

Ermilov, Sergey G. & Salavatulin, Vladimir M., 2023, Ontogenetic Instars Of Phyllhermannia Bimaculata Hammer, 1979 (Acari, Oribatida, Hermanniidae), Acta Zoologica Academiae Scientiarum Hungaricae 69 (1), pp. 11-24 : 13-16

Phyllhermannia bimaculata Hammer, 1979

( Figs 1–8 )

Main diagnostic traits of adult – ( Figs 1A–D ; 2A–C ; based on our data and data from HAMMER (1979) and LUXTON (1991)). Body length: 540–700. Body color brown, covered by thick layer of gel-like cerotegument, partially forming tubercles on dorsal side and foveate-reticulate ornamentation on epimeres I–III and leg segments; cuticle densely porose; epimeral border IV with some tubercles. Rostrum rounded. Dorsal part of prodorsum with two longitudinal, arch-like (concave in median part) ridges; interbothridial part of prodorsum with two oval, convex structures having one posterior tubercle; lateral longitudinal ridge present, extending basally into lateral (anterior) tubercle (opposite posterior lateral tubercle absent). Rostral and lamellar setae short, setiform, barbed; interlamellar seta medium-sized, broadly phylliform, barbed; bothridial seta long, bacilliform proximally and gradually dilating in distal half to well visible, flattened head having microscales; dorsal exobothridial seta spiniform; bs> in> ro = le> exd. Anterodorsal part of notogaster with median longitudinal and one pair of lateral semicircular band-like furrows resembling the shape of two large cells. Notogastral setae medium-sized, broadly phylliform, barbed. Subcapitular setae a and h setiform, roughened, m minute, simple (m 2 absent); a> h> m; adoral seta or 1 dilated and truncate distally, or 2 bacilliform. Palp with setation 0–1–1–3–9(+ω). Chelicera with two setiform, barbed setae; cha> chb. Epimeral setal formula: 3–1–3(4)–5(6); lateral setae of epimere III medium-sized, other setae short, setiform, all barbed. Genital, aggenital, adanal, and anal setae setiform, roughened or barbed. Adanal lyrifissure diagonal. Formulas of leg setation and solenidia (see Table 1): I (1–6–5–5–20) [1–2–1], II (1–6–5–5–15) [1–1–1], III (2–3–4–4–14) [1–1–0], IV (1–3–4–4–14) [0–1–0]; tc’ elongate phylliform on tarsi III, IV.

Description of juvenile instars ( Figs 2D ; 3A, B ; 4A–E ; 5A, B ; 6A, B ; 7A–D ; 8A–D ) – Measurements. Total length of larva: 270–285 (n = 16), protonymph: 330–345 (n = 8), deutonymph: 345–375 (n = 9), tritonymph: 435–510 (n = 4). Total width of larva: 120–135 (n = 16), protonymph: 150–173 (n = 8), deutonymph: 165–180 (n = 9), tritonymph: 225–240 (n = 4).

Integument. Body cuticle colorless (larva and protonymph) to light brownish (deuto- and tritonymph). Cuticle porose. Prodorsum with rare ridges; two of them well developed, diagonal, convergent, connected or separated medially. Interlamellar (between bothridium and prodorsal median ridge) and posterolateral gastronotic regions, and lateral parts of epimeres slightly tuberculate-reticulate in nymphal instars (versus indistinct in larva). Gastronotic and anogenital regions folded. Genital valves longitudinally striate. Subcapitular mentum and leg segments partially foveate-reticulate in nymphal instars.

Prodorsum. Triangular, about 2/3 length of gastronotic region. Rostrum rounded. Rostral seta (La: 5; Pn, Dn: 9–11; Tn: 15) setiform, erect, slightly barbed, divergent, located on tubercle. Lamellar seta (La: 5; Pn, Dn: 7–9; Tn: 9–11) similar in morphology to rostral setae in larva and protonymph versus slightly thickened or indistinctly phylliform in deuto-and tritonymph. Interlamellar seta (La: 5–7; Pn: 9–11; Dn: 15–22; Tn: 19–26) broadly phylliform, barbed. Bothridial seta (La: 60–64; Pn: 71–75; Dn: 82–86; Tn: 90–94) bacilliform proximally and gradually dilating in distal half to well visible, flattened head having microscales. Dorsal exobothridial seta (La, Pn, Dn: 7; Tn: 7–9) spiniform, smooth, located very close to bothridium. Ventral exobothridial seta represented by alveolus.

Gastronotic region. Prodorsum and gastronotum separated by folds. Posterior part rounded. Longitudinal ecdysial cleavage line well visible (transverse line not observed). Larva with 13 pairs of setae; h 3 vestigial, h 2 (13–15) setiform, erect, roughened, other setae (7) broadly phylliform, barbed. Nymphal instars with 16 pairs (Pn: p 1, p 2: 7–9, others: 9–11; Dn: p 1, p 2: 9–11, others: 15–22; Tn: p 1, p 2: 11, others: 19–26) of broadly phylliform, barbed setae (except p 2 and p 3 setiform, roughened in protonymph). Cupules ia and im and opisthonotal gland opening (near seta f

2

) visible, cupule ip not observed.

Gnathosoma. Subcapitulum size: La: 52–56 × 52–56; Pn: 71 × 64; Dn: 90 × 79; Tn: 97 × 86. Subcapitular setae a and h (La: a: 15–19, h: 9–11; Pn: a: 19, h: 11; Dn, Tn: a: 22–26, h: 15) setiform, roughened; m vestigial. Two pairs of adoral setae present; adoral seta or 1 (La: 7–9; Pn: 9; Dn, Tn: 11) dilated and truncate distally, or

2

(La: 7–9; Pn: 9; Dn, Tn: 11) setiform. Palp notogastral cerotegument; D = dorsal view

(La: 30; Pn: 37; Dn: 45; Tn: 52) setation: 0–1–1–3–9(+ω). Postpalpal seta (length: La: 15–19; Pn, Dn, Tn: 15) setiform, blunt-ended, erect, roughened. Chelicera (length: La: 64; Pn: 79; Dn: 101; Tn: 112) with two setiform, barbed setae (cha: La: 15–19; Pn: 22; Dn: 30; Tn: 34) distinctly barbed; chb: La: 9–11; Pn: 13; Dn: 17–19; Tn: 19–22) barbed.

Epimeral and lateral podosomal regions. Setal formulas for epimeres: La: 3–1–2 (third seta of first epimere forms protective scale over respective Claparède’s organ); Pn: 3–1–2–1; Dn: 3–1–2(sometimes 3)–3; Tn: 3–1–3–4. Epimeral setae (La, Pn: 7; Dn, Tn: 9–11) setiform, erect, roughened but setae 1a, 2a and 3a distally bifurcate in larval instar.

Anogenital region. Ontogeny of genital, aggenital, adanal, and anal setal formulas, larva to tritonymph, 0–1–4–7 (Pn: 11; Dn: one pair: 19–26, others: 7–11; Tn: one pair: 26–33, others: 9–11), 0–0–1–2 (Dn, Tn: 9–11), 0–0–3–3 (Dn, Tn: 9–11), 0–0–0–2 (Tn: 9–11), respectively. All setae setiform, roughened to barbed. Cupules ih, ips, iad appearing in normal ontogenetic pattern; becoming inconspicuous when shifted away from anal valves.

Legs. Claw of each leg strong, slightly barbed on dorsal side. Femora I–IV and trochanters III, IV with poorly visible ventroparaxial porose area. Formulas of leg setation and solenidia (see Table 1 for designations): La: I (0–2–3–4–16) [1–1–1], II (0–2–3–4–13) [1–1–1], III (0–2–2–3–12) [1–1–0]; Pn: I (0–4–4–5–16) [1–1–1], II (0–4–4–4–13) [1–1–1], III (1–2–2–3– 12) [1–1–0], IV (0–0–1–0–7) [0–0–0]; Dn: I (1–5–4–5–16) [1–2–1], II (1–5–4–5–13) [1–1–1], III (2–3–2–3–12) [1–1–0], IV (1–2–2–3–12) [0–1–0]; Tn: I (1–5–5–5–18) [1–2–1], II (1–5–5–5–13) [1–1–1], III (2–3–3–4–12) [1–1–0], IV (1–3–3–4–12) [0–1–0]. Tibiae I–IV and genua I–III with seta d coupled with respective solenidion; it”, it’ absent on all tarsi; tc’ elongate phylliform on tarsi III, IV; ft’ absent on tarsus III.

Figures

Fig. 1. Phyllhermannia bimaculata Hammer, 1979, adult, SEM micrographs: A, B = dorsal view; C = ventral view; D = ventrolateral view

Fig. 2. Phyllhermannia bimaculata Hammer, 1979, adult (A–C) and protonymph (D), SEM micrographs: A = dorsoanterior view; B = right lateral view; C = notogastral seta e1 and

Fig. 3. Phyllhermannia bimaculata Hammer, 1979, deutonymph, microscope images:A = dorsal view; B = right lateral view

Fig. 4. Phyllhermannia bimaculata Hammer, 1979, larva (A–C) and protonymph (D, E): A, D = dorsal view; B, E = ventral view (gnathosoma and legs except trochanters not shown); C =

Fig. 5. Phyllhermannia bimaculata Hammer, 1979, deutonymph: A = dorsal view; B = ventral view (gnathosoma and legs except trochanters not shown). Scale bar 50 μm

Fig. 6. Phyllhermannia bimaculata Hammer, 1979, tritonymph: A = dorsal view; B = ventral view (gnathosoma and legs except trochanters not shown). Scale bar 50 μm

Fig. 7. Phyllhermannia bimaculata Hammer, 1979, gnathosoma (dissected and pressed) of larva: A = subcapitulum, ventral view; B = left lip with adoral setae; C = palp, right, an-

Fig. 8. Phyllhermannia bimaculata Hammer, 1979, legs of larva (A–C) and protonymph (D): A = leg I, left, paraxial view; B = leg II, right, antiaxial view; C = leg III, left, antiaxial view; D = leg IV, left, antiaxial view. Scale bars 20 μm