Nothrus bilongisetosus, Ermilov, Sergey G. & Hugo-Coetzee, Elizabeth A., 2012

Ermilov, Sergey G. & Hugo-Coetzee, Elizabeth A., 2012, The oribatid mite genus Nothrus Koch, 1836 (Acari: Oribatida: Nothridae) of South Africa, including a key to African species, Zootaxa 3243, pp. 29-51 : 30-35

Nothrus bilongisetosus sp. nov.

( Figs. 1–29 )

Diagnosis. Body length 717–796 × 320–365; dorsal side and anogenital region of body alveolate (diameter of alveoli up to 10 on prodorsum and 16 on notogaster); prodorsal setae covered with broad, phylliform cerotegument; interlamellar setae longer than lamellar and rostral setae; sensilli 164–205, rod-like, barbed; notogastral setae h 2 (287–369) and p 1 (164–205) setiform, longest on notogaster, other notogastral setae and also anogenital and epimeral setae considerable shorter, covered with phylliform cerotegument; distance between setae c 1– c 2 shorter than between c 2– c 3; epimeral setal formula 7–4–5–6; hypostomal setae h covered with phylliform cerotegument, others (m 1, m 2, a) setiform, slightly barbed; two pairs of adoral setae: or 1 simple, slightly thickened; or 2 expanded distally, truncate; leg tarsi with one claw.

Description. Adult.

Measurements. Body length 717 (holotype, female), 730–796 (mean 762; n = 10); body width 320 (holotype), 330–365 (mean 343; n = 10).

Integument. Body color yellow-brownish to brown. Dorsal side and anogenital region of body alveolate (diameter of alveoli up to 10 on prodorsum and 16 on notogaster). Sternal region slightly folded, epimeres with dense microfoveolae, rarely larger foveolae. Genital plates slightly folded.

Prodorsum ( Figs 1 , 4–9). Rostrum broadly rounded, with short medial indentation in dorsal view. Rostral (ro, 20–28), lamellar (le, 12–16), interlamellar (in, 49–53) and exobothridial (ex, 16) setae covered with broad, phylliform cerotegument, set on small tubercles. Sensilli (ss) longest setae on prodorsum (164–205), rod-like, barbed.

Notogaster ( Figs 1, 3 , 10–17). Weakly convex in dorso-central and dorso-lateral part and with circummarginal furrow between them (visible only in dorso-lateral and dorso-caudal views). Sixteen pairs of notogastral setae set on tubercles. Setae h 2 (287–369) and p 1 (164–205) setiform, covered with thin layer of cerotegument. Other setae considerably shorter (many of these 41–49, except c 2 24–32, f 2 61–69, h 1 49–53, h 3 49–57, p 2 36–49, p 3 24), covered with broad, phylliform cerotegument. Distance between setae c 1– c 2 shorter than between c 2– c 3. Lyrifissures ia and im not evident. Large opisthonotal gland opening (gla) present postero-lateriad f 2.

Anogenital region ( Figs 2, 3 , 18–21). Two pairs of anal (an 1 and an 2 18–22), three pairs of adanal (ad 1 32–36, ad 2 24–28, ad 3 20–24) and nine pairs of genital setae (g 1– g 9 16–20) with covered phylliform cerotegument, set on small tubercles. Lyrifissures ian and iad clearly visible, others (ih, ips and ip) not evident.

Epimeral region ( Figs 2 , 22, 23). Epimeral setal formula 7–4–5–6. Setae short, 16–20 (only 1d longer, 24–32), covered with phylliform cerotegument, set on small tubercles.

FIGURES 4–13. Nothrus bilongisetosus sp. nov., adult: 4—rostral seta; 5—lamellar seta; 6—interlamellar seta; 7—sensillus; 8—apical part of sensillus; 9—exobothridial seta; 10—microsculpture of notogaster between setae d 2; 11—notogastral seta c 1; 12—notogastral seta c 2; 13—notogastral seta f 2. Scale bars (4, 8, 9) 10 μm, (5, 6, 10–13) 20 μm, (7) 50 μm.

Gnathosoma ( Figs 24–27 ). Subcapitulum longer than wide (151–155 × 114–118). Hypostomal setae h 24–28, covered with broad, phylliform cerotegument; other setae (m 1 12–16, m 2 4–8, a 24–28) setiform, slightly barbed. Two pairs of smooth adoral setae (or, 12–16): or 1 simple, slightly thickened; or 2 modified, expanded distally, truncate. Palps 73–77, with setation 0–1–1–3–9(+1ω). Solenidion long, slightly thickened, blunt-ended, not coupled with acm. Chelicerae 155–164; cheliceral setae long, setiform, barbed; cha (45–49) longer, than chb (20–28). Trägårdh’s organ clearly visible.

Legs ( Figs 28, 29 ). Tarsi with one smooth claw. Formulae of leg setation and solenidia: I (1–9–5–6–27) [1–2– 3], II (1–8–5–5–25) [1–1–1], III (4–5–5–5–22) [1–1–0], IV (2–6–5–5–22) [1–1–0]; homology of setae and solenidia indicated in Table 1. Setae covered with broad, phylliform cerotegument (except setiform p, tc, ft, u, a, s, pv, v 1– v 3 on tarsi, setae d on tibiae and genua and some ventral setae on tibiae, genua, femora). Famulus short, setiform, pointed. All solenidia rod-like, blunt-ended.

Leg Trochanter Femur Genu Tibia Tarsus

I v' d, (l1), (l2), bv'', d σ, (l), (v) d φ 1, (l1), l2'', (v), φ 2 (ft), pl', (l1), (l2), (l3), (tc), (p), (u), (a), s,

v1 '', v 2'', v 3'' (pv), (v 1), (v 2), (v 3), e, ω 1, ω 2, ω 3

II v' d, (l1), (l2), bv'', d σ, (l), (v) d φ, (l), (v) (ft), (l1), (l2), (l3), (tc), (p), (u), (a), s, (pv),

v1 '', v 2'' (v 1), (v 2), (v 3), ω 1

III l'1, l'2, l'3*, v' d, (l), bv'', v'' d σ, (l), (v) d φ, (l), (v) (ft), (l1), (l2), (tc), (p), (u), (a), s, (pv), (v 1),

(v 2), v 3'

IV v' d, (l1), l2'', bv'', v'' d σ, (l), (v) d φ, (l), (v) (ft), (l1), (l2), (tc), (p), (u), (a), s, (pv), (v 1),

(v 2), v 3'

Roman letters refer to normal setae (e to famulus), Greek letters to solenidia; d σ, d φ – setae and solenidia coupled. Single prime

(') marks setae on anterior and double prime (") setae on posterior side of the given leg segment. Parentheses refer to a pair of

setae. *Setae absent in two specimens of Nothrus anauniensis .

FIGURES 14–23. Nothrus bilongisetosus sp. nov., adult: 14—notogastral seta h 2; 15—notogastral seta p 1; 16—notogastral seta p 2; 17—notogastral seta p 3; 18—anal seta an 2; 19—adanal seta ad 1; 20—adanal seta ad 3; 21—genital seta g 5; 22—epimeral seta 1a; 23—epimeral seta 1d. Scale bars (14, 15) 50 μm, (16–23) 10 μm.

Type material and type deposition. The holotype (3662.38.1) and 10 paratypes (3662.38) have the following collection data: South Africa, Eastern Cape, Cintsa, 32º48‘S, 28º05‘E, in decomposed plant debris, collected by C.M. Engelbrecht, 1 December 1989.

The holotype and three paratypes are deposited in the National Museum, Bloemfontein, South Africa. Five paratypes are deposited in the collection of Zoological Institute of Russian Academy of Sciences, St. Petersburg, Russia. Two paratypes are in the personal collection of the first author.

Other material. The known distribution of N. bilongisetosus sp. nov. is indicated by filled triangles on the map of South Africa Fig. 88 . Sodwana Bay KZN (27º32’S, 32º39’E, well wooded area near beach); between Sibasa and Punda Maria LP (22º57’S, 30º31’E, dry soil and decomposed leaf material under indigenous trees).

Etymology. The specific name “ bilongisetosus ” refers to the two long pairs of notogastral setae (h 2, p 1).

Remarks. Nothrus bilongisetosus sp. nov. can be included in the Nothrus species group with two pairs of long notogastral caudal setae: N. angolensis Balogh, 1958 from Angola (see Balogh 1958), N. leleupi Balogh, 1958 from Tanzania (see Balogh 1958), N. quadripilus Ewing, 1909 from the eastern part of the USA (see Seniczak & Norton 1993), N. reunionensis Mahunka, 1978 from Reunion (see Mahunka 1978) and N. septatus Golosova & Karppinen, 1985 from the northern part of Russia (see Golosova & Karppinen 1985). However, N. bilongisetosus sp. nov. clearly differs from all the other species in this group:

— from N. angolensis by the body width (320–365 vs. 405–420 in N. angolensis ), caudal setae longer and h 2 considerable longer than p 1 (h2 287–369, p 1 164–205 vs. h 2 150–170, p 1 135–145 in N. angolensis );

— from N. leleupi by the smaller body size (717–796 × 320–365 vs. 980 × 580 in N. leleupi ), sensilli and lamellar setae shorter (ss 164–205, le 32–36 vs. ss 275–290, le 55 in N. leleupi ), leg tarsi with one claw (three claws in N. leleupi ), caudal setae longer (h 2 287–369, p 1 164–205 vs. h 2 190, p 1 100 in N. leleupi );

— from N. quadripilus by the smaller body size (717–796 × 320–365 vs. 820 × 380 in N. quadripilus ), centrodorsal gastronotic setae d 1, d 2, e 1 short, not reaching insertions of setae of following row (d 1, d 2, e 1 longer, reaching insertions of setae of following row in N. quadripilus ), caudal setae h 2 considerable longer than p 1 (h 2 little longer than p 1 in N. quadripilus );

— from N. reunionensis by the body width (320–365 vs. 380–395 in N. reunionensis ), sensilli shorter (164–205 vs. 220 in N. reunionensis ), leg tarsi with one claw (three claws in N. reunionensis ), caudal setae longer (h 2 287–369, p 1 164–205 vs. h 2 200–250, p 1 120–140 in N. reunionensis );

— from N. septatus by the body width (320–365 vs. 405–420 in N. septatus ), leg tarsi with one claw (three claws in N. septatus ), caudal setae long, h 2 considerable longer than p 1 (h 2 and p 1 considerable shorter, little difference in length in N. septatus ).

Figures

FIGURE 88. Known localities of Nothrus bilongisetosus sp. nov. (filled triangles), N. monolongisetosus sp. nov. (filled circles) and N. anauniensis Canestrini & Fanzago (filled squares) in South Africa.

FIGURES 1 – 3. Nothrus bilongisetosus sp. nov., adult: 1 — dorsal view; 2 — ventral view, subcapitular setae, palps and legs (except trochanters) not shown; 3 — posterior part of notogaster, lateral view. Scale bars (1, 2) 200 μm, (3) 100 μm.

FIGURES 24 – 29. Nothrus bilongisetosus sp. nov., adult: 24 — left half of subcapitulum; 25 — right lip with adoral setae; 26 — palp; 27 — anterior part of chelicera, lateral view; 28 — leg I, left, paraxial view; 29 — leg IV, right, antiaxial view. Scale bars (24, 28, 29) 50 μm, (25) 10 μm, (26, 27) 20 μm.